Wikipedia talk:WikiProject Mathematics/Archive2007

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Jan 2007

This is the archive file "Wikipedia talk:WikiProject Mathematics/Archive 21". It is for January 2007.

Jasna Mađarević

Could someone take a look here? The article is about Serbian mathematician and is on AfD. TIA Pavel Vozenilek 02:32, 1 January 2007 (UTC)

Nonsense in Liber Abaci and Egyptian fraction

I'm getting very tired of repeatedly reverting Milo Gardner's changes (some under Milogardner (talk · contribs), some under various 172.x.x.x addresses) to Liber Abaci and Egyptian fraction, which I see as...not wrong exactly, but badly written, off-topic, giving undue weight to fringe points of view, and generally damaging to the usefulness and readability of the articles. And I'm a little worried that in doing so I'm becoming too single-minded myself and may be violating WP:OWN. Someone else want to give me a reality check, are his edits really as revert-worthy as I think they are? As an example, here is the diff from a sequence of 11 of his edits that I reverted with the somewhat abrupt summary "rv incomprehensible damage", which he took exception to. Was I too harsh? —David Eppstein 19:44, 1 January 2007 (UTC)

I don't have time to help out now, or in the coming days, but I'll just note that I had quite some problems with Milo on ancient Egyptian mathematics, see the talk page and also my user talk page. He obviously knows quite a bit about that, but he is unable to write it down in a format suitable for Wikipedia; specifically, his contributions are not neutral, but seem to be written in order to push certain theories which are not mainstream (e.g., remainder arithmetic). That's my own opinion, but it matches well with David's observations. -- Jitse Niesen (talk) 20:41, 1 January 2007 (UTC)
Without trying to follow the math, I observe that both articles contain a lot of derivations and many attempts to show the affinity of ancient and modern methods. Although we seem to tolerate a fair number of do-it-yourself derivations in the mathematics pages, strict application of policy would probably say that we should only repeat derivations published by others, and we should only make historical comparisons that have been published by others. On that view, both articles would probably become shorter. As to your specific revert in Liber Abaci, I have no complaints. The bibliography in Egyptian fraction looks huge, with many esoteric entries. Most of these are not cited in the text. It might perhaps be shortened by including a link to an online article with a good bibliography. EdJohnston 21:05, 1 January 2007 (UTC)
Gardner clearly has a lot of expertise on the subject, but his inability to write an intelligible sentence seriously detracts from the value of his contributions. I don't think you were too harsh. -- Dominus 23:52, 3 January 2007 (UTC)

Article listed for deletion

Wikipedia's mathematicians may wish to give their opinions at Wikipedia:Articles for deletion/List of books in computational geometry. Michael Hardy 01:54, 4 January 2007 (UTC)

Laplace-Runge-Lenz vector is now FAC

Hi, I just nominated Laplace-Runge-Lenz vector to be a Featured article candidate. Hopefully, you all think that the article is excellent and can support it. ;) But if not, please offer constructive criticisms on how it might be improved, which will be much appreciated. Thanks very much for your help! Willow 10:49, 31 December 2006 (UTC)

Is this not better described as Physics or Astronomy rather than Mathematics? JRSpriggs 05:23, 5 January 2007 (UTC)

Section Hyperreal number#Polynomial_ratio_construction

This section contains the following assertion

Let any relation of real polynomials in a single variable and their ratios hold when and only when they hold for all but a finite number of natural number values of the variable. The proof that first-order statements about polynomial ratios have the same truth value as corresponding first-order statements about standard real numbers is much the same as the proof for the ultrapower model, but requires only the use of a cofininite or Fréchet filter, not ultrafilters or the Axiom of Choice.

I find this dubious, although examination by a model theorist would be appreciated.--CSTAR 19:41, 3 January 2007 (UTC)

Hmmm. It's true for any infinite set of natural numbers, instead of merely all but a finite number of natural numbers. The result follows from the trivial result that any polynomial with an infinite number of roots is identically 0. I don't know if I could come up with a model-theoretic proof, though. — Arthur Rubin | (talk) 21:19, 3 January 2007 (UTC)
I can see how to reason thus if all the relations in question were elementary equations. If other relations, such as inequalities, are also considered, I'm less sure that it is trivial. Henning Makholm 22:45, 3 January 2007 (UTC)

It sounded what like he was saying that a particular mapping is an elementary equivalence embedding.

Your interpretation of this seems to be that for any n-ary relation R if I is an infinites subset of R

 R\bigg(\frac{P_1(x)}{Q_1(x)}, \ldots , \frac{P_n(x)}{Q_n(x)}\bigg), \quad \forall x \in I

holds if and only if

 R\bigg(\frac{P_1(x)}{Q_1(x)}, \ldots , \frac{P_n(x)}{Q_n(x)}\bigg), \quad \forall x \in \mathbb{R}

This is certainly true for polynomial relations (e.g. in case there is a polynomial Q for which

 R(s_1,  \ldots, s_n) \mbox{ holds iff } Q(s_1, \ldots, s_n) = 0

But I don't think I understand what you said in general. Take

 n=1, P_1(x) = x, Q_1 = 1

and

 R(s) \mbox{ being the  unary predicate } s > 0

x > 0 is true for an infinite set of integers, but it's certainly not true for all reals. Am I missing something?--CSTAR 21:51, 3 January 2007 (UTC) PS. Note also that the polynomial x^2 - x \geq 0 for all integers x, but is negative in the open interval ]0,1[. --CSTAR 22:01, 3 January 2007 (UTC)

It makes more sense to me if read as: "If, for all choices of polynomials, the relation holds for an infinite (co-finte) set of integers (which may depend on the polynomials, then the relation holds for all reals". That is, you're supposed to take some closed formula and systematically substitute every quantification over reals into a quantification over polynomial ratios. So your counterexample is not a counterexample, because there are certainly polynomials for which s>0 do not hold for any integers at all. Henning Makholm 22:37, 3 January 2007 (UTC)
OK that I think I believe. There are still some details that need to be ironed out. Particularly, that this field is non-archimedean. But I guess the polynomial ratio x/1 will do the trick since for any (standard) integer n, x/1 - n > 0 holds. --CSTAR 22:54, 3 January 2007 (UTC)
This latter construction still doesn't look right; as x2 != 2 is true for all rationals, (and hence all polynomials with integer coefficients evaluated over the integers), but not for all reals. Perhaps the only situations in which it makes sense is for polynomial equalities, in which case my first assertion is accurate. — Arthur Rubin | (talk) 14:04, 4 January 2007 (UTC)
OK this is even worse than I had originally thought; since it appears the language for which the mapping of the reals into polynomial ratios is an elementary embedding, cannot even include negation! --CSTAR 18:30, 4 January 2007 (UTC)

Hmm, it seems that trying to reason out the mathematical truth here is likely to confuse everybody, including every future editor who may try to figure out the claim. Let's revert to basic Wikipedia principles: we need to get a source for the claim, and then we can discuss whether the article accurately represents the claim made in the source. In the absence of sources, remove the claim. Henning Makholm 23:22, 4 January 2007 (UTC)

The complex plane

I've just finished adding quite a bit of new material to this article, which had been marked as a "stub". I would appreciate some feedback, either here or on my talk page. Is the article too long? Or just about right? I think this particular topic should be of some interest to the general reader, so I tried to keep it all as non-technical as I could. Does that approach make sense? Etc.

I could also use some advice on one thing. Rgdboer had raised a question about other meanings of the phrase "complex plane" on the article's talk page. So I added a section Complex plane#Other meanings of "complex plane" to discuss, briefly, the concepts of split-complex numbers, dual numbers, and the Cartesian product C×C. I'd like to write a little bit more for that section, but I'm not sure I understand these three objects well enough to figure out exactly what to say.

The first two "other complex planes" seem as if they'd hardly work well for analysis, except for some rather specialized applications in physics. And the two-dimensional vector space C×C is sort of tricky as well – right off the top of my head, I'm not even sure how to define a useful norm for that space. So I could use some help figuring out what else to say in that section of the article, if anybody here is willing to help.

Thanks! DavidCBryant 20:05, 6 January 2007 (UTC)

We have just been through a series of changes at Complex number#Conversion from the Cartesian form to the polar form concerning the computation of the argument of a complex number. The simplistic formula you give, \theta = \arctan \frac{y}{x}, is only correct when x > 0\!. JRSpriggs 09:37, 7 January 2007 (UTC)
Thanks for pointing that out. I'm not sure what I was thinking; just absent-minded, I guess. I've changed it – you may or may not like this other idea, which is
\theta = \arg(z) = -i\log\frac{z}{|z|}.\,
I took a closer look at the article about complex numbers, and I'm not sure I agree with the way this problem is treated there. Maybe I'll jump in on that article's talk page. DavidCBryant 15:13, 7 January 2007 (UTC)

A bug?

I used to be able to reach the article Methods of computing square roots by going through the category Category:Root-finding algorithms. However, now when I look in that category, the article does not appear on my screen. None the less, the file has not been edited to remove it from the category. Nor has the category been changed in a way that would have that effect. Could this be a new bug in the software for displaying the contents of a category? Help! JRSpriggs 09:25, 7 January 2007 (UTC)

When I checked the category just now, the article was there (under M, of course). --KSmrqT 12:13, 7 January 2007 (UTC)
I think it's working now. I removed an external reference to a web page right here that wouldn't respond when I pinged it. I'm not sure if the dead link was the problem, or if the Cyrillic characters displayed on the page were at fault, but the article shows up in the category list now. Oh -- why was the description of this site written in Russian? I can understand linking to foreign language web sites, but I don't understand why the link should be described in a foreign language on this end. DavidCBryant 12:30, 7 January 2007 (UTC)
PS to KSmrq – That's weird! I removed the broken link in the article, then sat here a while thinking about another problem before finally writing my response. The problem Spriggs reported was definitely showing up for me before I took the Russian language stuff out of the article. You checked the category while I was sitting here thinking about something else. DavidCBryant 12:37, 7 January 2007 (UTC)

Monty Hall problem

Monty Hall problem has been nominated for a featured article review. Articles are typically reviewed for two weeks. Please leave your comments and help us to return the article to featured quality. If concerns are not addressed during the review period, articles are moved onto the Featured Article Removal Candidates list for a further period, where editors may declare "Keep" or "Remove" the article from featured status. The instructions for the review process are here. Reviewers' concerns are here. Gzkn 10:57, 7 January 2007 (UTC)

The first reason cited for needing review? "Has one inline citation." Here we go again. --KSmrqT 12:18, 7 January 2007 (UTC)

Collatz conjecture

I have seen a few references to a proof by this paper. It is listed in Québec Science's (ISSN 0021-6127) February 2006 special issue as one of the 10 top scientific breakouts made by Quebec scientists in 2006. Can somebody more knowledgeable than myself in maths look into that? Circeus 18:17, 10 January 2007 (UTC)

It doesn't prove the Collatz conjecture. What it does is to define a related probabilistic model in which a gambler, starting from an initial stake of A dollars, repeatedly flips a fair coin and based on the result replaces A with either A/2 or (3A+1)/2, and shows that this model leads almost surely to becoming broke. To me this seems very unsurprising. —David Eppstein 18:41, 10 January 2007 (UTC)
The paper requires a subscription, so I haven't seen it. What you describe seems to have a tenuous (or more accurately no) relation to the 3x+1 problem. It would seem to me, that to have some relation to the Collatz problem the parity of A should have some bearing on the next element of the sequence.--CSTAR 19:00, 10 January 2007 (UTC)
There is a free online paper by Alain Slakmon and Luc Macot. Also this online commentary (in French). My loose translation of Slakmon's summary:
"As we're talking about a probabilistic approach, we can't assert that there is an absolute proof of the truth of the conjecture. There remains a very small probability that certain numbers violate it," says Alain Slakmon. "But this possibility is now infinitely small". EdJohnston 19:45, 10 January 2007 (UTC)
Well, their solution is exactly as David Eppstein described it. I think that the commentary (CQFD) is hyperbole. I am very skeptical whether this really gets us any further to solution of this problem.--CSTAR 20:07, 10 January 2007 (UTC)

Missing articles

I was looking at the list of missing math articles at Wikipedia:Missing science topics/Maths1 and considering writing up some stubs (or perhaps a bit more) for a few topics, but it seems to me that many of these probably aren't sufficiently notable. For example, 0-free has an article on mathworld at Zerofree, and there seem to be one or two articles on it plus a sequence at the OEIS (which means nothing, really), but that probably doesn't satisfy the notability criteria. In fact, this is probably true of most of the terms in that list (even ignoring the ones that should probably be sections in other articles).

Am I right about this? Should I remove the links for topics that don't seem to be notable? Your opinions will be appreciated. --Sopoforic 02:39, 11 January 2007 (UTC)

Those lists are a compilation from such sources as MathWorld, PlanetMath, Springer's encyclopedia, etc. It is quite likely that a bunch of them are not notable. However, creating redirects to existing articles covering those concepts would be preferable to just removing those links from the lists I would think. Oleg Alexandrov (talk) 04:38, 11 January 2007 (UTC)
Well, sure, where possible. But in the example I cited, zerofree, we don't have any article to redirect it to. There are enough sources to make it verifiable, but it probably doesn't count as notable, in my opinion. My question is, granted that a thing is not notable, should I remove it from the list, or is it serving some greater purpose by being there? I was just going to remove such things, but I thought I should ask since I don't know if these lists are used for anything else than finding articles to write. --Sopoforic 14:37, 11 January 2007 (UTC)
You can remove unhelpful entries, no problem. The only issue is that when my bot updates those pages again, it may put those removed entries back. Perhaps, as you remove those entries, you could put them in a list for me, so that I make sure the bot remembers those and does not add them back the next time around. Oleg Alexandrov (talk) 17:11, 11 January 2007 (UTC)
An even better solution could be I think to just ignore the non-notable entries. It is very likely a good chunck of those redlinks will never turn blue. We could as well focus on the ones which are worth filling in and glossing over entries that don't appear relevant. Oleg Alexandrov (talk) 17:15, 11 January 2007 (UTC)
The problem with that is that if they are left on the list, other people will also have to evaluate them to see if they are notable, which is duplication of effort and ought to be avoided. --Sopoforic 17:39, 11 January 2007 (UTC)
This discussion got me curious enough that I went and reread the stuff about "Notability". Did you read the additional stuff at Wikipedia:Notability (numbers), Sopoforic? It looks as if "zero-free" might be notable, at least IMV. Oh – this reminds me of an old joke. Every positive natural number is unusual. The proof is by induction. Assume the theorem is false. Since the set of all positive natural numbers is bounded below, the set of all positive natural numbers that are not unusual must have an infimum x. But that's a pretty unusual property for x to have ... should we swap "unusual" with "not notable"?  ;^> DavidCBryant 17:26, 11 January 2007 (UTC)
Eh, the one that gives me difficulty is the first: "do mathematicians publish papers about it." Most anything that can be imagined will have one or two papers published about it, and zerofree only seems to have one that I'm sure is about that particular meaning (need to visit the library so that I can read the full text of the other articles). The notability guidelines generally go 'multiple non-trivial works' so I didn't think that just one paper was necessarily sufficient.
I suppose that I can just create articles for these and let AfD decide whether they're notable, should they be nominated for deletion, but I'd prefer not to waste effort. Still, it may be the best solution--I've probably already taken more time trying to decide whether zerofree was notable than I would have spent making a brief article on the subject. --Sopoforic 17:39, 11 January 2007 (UTC)
I prodded N-th triangular number squared a few days ago for notability. I would suggest prioritizing your new articles to create the most important ones first. It's a waste of everyone's effort to create articles if they are likely to be nominated for deletion quickly. CMummert · talk 17:48, 11 January 2007 (UTC)
While I agree that there are many non-notable items in these lists and many non-notable sequences in OEIS, I'm not convinced that N-th triangular number squared is a good example of such. The fact that the sum of consecutive cubes is a square, and moreover a square of a different important number sequence, is I think surprising and notable. OEIS gives seven references and a quick search found five more, including Stroeker, R. J., "On the sum of consecutive cubes being a perfect square", Compositio Math. 97 (1995), no. 1-2, 295--307, and Kanim, K., "The Sum of Cubes—An Extension of Archimedes' Sum of Squares", Proofs without Words, Mathematics Magazine, October 2004, 298-299. I don't have time to write more about this now (or fix up the article so that it is worthy of surviving your prod, which I think should include giving it a less cumbersome name — "squared triangular number" maybe?) but will try to take another look tonight. —David Eppstein 18:48, 11 January 2007 (UTC)
I agree that that article is on the edge of what is notable for a number and what is not; I happen to feel it is on the opposite side. Do you agree that a topic that is clearly more notable than that is notable enough? CMummert · talk 20:05, 11 January 2007 (UTC)
Yes. I also agree that the article as it stands isn't worth including; the bulk of the text (an easy inductive proof) is more filler than content. But I think it has potential to be above-threshhold. —David Eppstein 22:50, 11 January 2007 (UTC)
(The indenting gets to be a little extreme, I think ...) All kidding aside, Sopoforic, I' d like to offer a helpful suggestion or two. Those lists are certainly intimidating. I went through the first one only, and on a quick read-through hit just one item (Almost integer) that I've already thought of writing about. The idea I had there is that
\frac{3^{12}}{2^{19}} \approx 1.0136\,
is the basis for Western music (well, the circle of fifths and Bach's well-tempered scale, at least), and that might provide an interesting tie-in to Ramanujan's continued fractions, which come a whole lot closer to being integers. Oh, yeah ... another interesting example is
e^3 \approx 20 \quad\Longleftrightarrow\quad \ln20 \approx 3\,
which, together with ln2 ≈ 0.7 is good enough to do a lot of mental arithmetic to one significant figure – three figures if you can think of ln2 ≈ 0.69315 (and this is the type of skill that is dying out all too quickly in the computer age, I think.) Anyway, the lists are terribly intimidating simply because they're so long. Can we maybe coordinate with Oleg somehow to split out the most notable missing articles so that new authors won't feel like they're undertaking a Sysiphean endeavor?
The other practical suggestion I'd make is to just start reading the articles on Wikipedia in areas that interest you. I started working on this stuff less than two months ago. I quickly found that there was practically nothing in Wikipedia about continued fractions with complex elements. Even the fairly prominent articles like complex analysis and complex plane seemed woefully inadequate. I've managed to put quite a bit into the article about the "complex plane", but complex analysis could still benefit from a whole lot more information of a general nature (such as an introduction to analytic continuation, and something about conformal mapping and its applications, etc). It would be good to prioritize the new article lists somehow, but even if that isn't done I bet you can find something good to write about if you just read some of the articles that are already here. DavidCBryant 19:32, 11 January 2007 (UTC)
I do read the articles quite a lot, but I only occasionally run across something I feel qualified enough to write about even with references. I suppose anyone (even I) could write the tiniest of stubs about most topics, but I'd hoped to be able to make a somewhat more substantial contribution. Thus, I was browsing through the missing articles list in search of something I understood.
I think it might be nice if these were categorized, as the requested articles are, since I've never even heard of many of these things. But, there are too many topics listed--we'd never get finished even categorizing them, I suspect. --Sopoforic 20:24, 11 January 2007 (UTC)
Even if they are categorized, it would take forever to create them all. But that's not even the purpose, really. As I view things, that list exists for the following reason: People bump into it, see a redlink, and say "gosh, I know about this". Then people end up writing one or more articles. So, that list is meant to "inspire" I would think, rather than be a to-do list.
In short, I'd suggest you take a look through the lists, see a topic which you feel is important, and which you know about, and write an article about it. On another day, you have nothing to do, then do the same thing. :) Oleg Alexandrov (talk) 04:33, 12 January 2007 (UTC)
Yeah, I get that. I just mean it'd be nice to have them categorized since, for example, I'm not very interested in analysis at all, but I'm pretty interested in combinatorics. So for me, I'd be more likely to bump into an article I could write/would want to write if they were by topic. But, like I said, the effort would surely be disproportionate to the benefit, and not in a good way. (Even the argument I gave seems falsified: I came across Kirkman's schoolgirl problem looking at the list, and it's very interesting indeed, so I made that article. Hopefully this will be a regular occurrence!) --Sopoforic 04:55, 12 January 2007 (UTC)

It may have been mentioned above, but in case it hasn't, the PlanetMath exchange project links are categorized. See Wikipedia:WikiProject_Mathematics/PlanetMath_Exchange if you wanna help out. Lunch 17:46, 12 January 2007 (UTC)

I wouldn't remove something merely because it does not seem notable to me, but maybe I would remove things that seem not notable to me. Michael Hardy 00:14, 13 January 2007 (UTC)

Florentin Smarandache on afd

Hello. I have put Florentin Smarandache on articles for deletion. See: Wikipedia:Articles for deletion/Florentin Smarandache. Please vote. Wile E. Heresiarch 06:18, 14 January 2007 (UTC)

Exponentiation

If anyone is interested, I could use a hand at exponentiation to get the content up to par and resist the efforts of a certain editor to add nonstandard definitions for complex exponentials, roots of unity, etc. CMummert · talk 15:04, 14 January 2007 (UTC)

Commercial / Business Math

I can't find a topic for an important branch of lower mathematics: that which is often called commercial math or business math. It is a practical subject, emphasizing simple arithmetic, percentages, and fractions, but also covering things such as banking transactions (writing checks, for example), purchase orders and invoices, consumer and business loans, etc. All of these things have a mathematical component, or at least a computational one, and they are very widely taught in commercial courses around the world. Does this subject have an article? If not, should it? What should it be called? —The preceding unsigned comment was added by Lou Sander (talkcontribs) 00:30, 14 January 2007 (UTC).

Oops! When I copied this over from elsewhere, I didn't want to include the out-of-date signature. Then I didn't put in a new one. (Another reason ALWAYS to preview.) Sorry. Lou Sander 00:33, 14 January 2007 (UTC)

There's a perfunctory stub on elementary mathematics. It isn't very good, even as stubs go (specifically, it focuses too much on a particular structure of education). Maybe you'd like to expand it, adding a section for business math? --Trovatore 00:49, 14 January 2007 (UTC)
Good idea. Better might be a separate article, though. Whichever way it goes, there needs to be a proper name for the subject. I think of it as "business math" or "commercial math," but those names might be old-fashioned, especially the second one. I teach a course in this stuff, and the famous textbook publisher calls it "college math," which I think is neither appropriate nor descriptive. What on earth do we call this important but pedestrian subject?? Lou Sander 01:08, 14 January 2007 (UTC)
Well, business math might be reasonable as a name for an article about a course (or a "topic" as our English friends, for some odd reason, call it). We have other articles on courses, such as pre-algebra. I guess the question is, if the article is not to be about a course, then what exactly is it about? I don't see that there's any other real unifying theme to the subject matter under discussion. --Trovatore 01:21, 14 January 2007 (UTC)
The unifying theme is its everyday usefulness in commerce. It is what most people think of when they think of "math." ("Most people" being the working classes, etc.) Lou Sander 05:15, 14 January 2007 (UTC)
I suppose that would fall under Elementary mathematics then, but why restrict it to business only? Elementary mathematics would have applications in all kinds of things; cooking, carpentry, sports, business, politics, etc. If you're interested in concentrating just on the business aspect however, you may want to check out the related topics under Business. It sounds like it would fit under the general topic of business as opposed to mathematics. I don't know if there's a talk page similar to this one in the Business subject though. capitalist 07:20, 14 January 2007 (UTC)
EDIT: I looked through the Mathematics Subject Classification briefly but couldn't really find a logical place for "business math". That's why I'm thinking it's more of a business subject than a mathematical one and would be better addressed by that community. capitalist 07:25, 14 January 2007 (UTC)
(Responding to Lou Sander) What I'm saying is that the difference between mathematics used in everyday commerce, and other mathematics, is not inherent to the subject matter; rather, what you seem to be discussing is one particular set of applications of techniques that have non-business applications as well. So you could have an article called applications of mathematics to business or some such, if that's the topic you're trying to get at. But those mathematical topics are not an inherently businessy sort of math, which is why I wouldn't be enthusiastic about lumping them into a business mathematics article. (Though, as I say, a business math article about the course taught under that name would be reasonable. --Trovatore 07:50, 14 January 2007 (UTC)
Update: Wow, business mathematics came up blue -- wasn't expecting that. It seems to be about the course. --Trovatore 07:52, 14 January 2007 (UTC)
Interesting (and thanks for finding it!). I thought I had looked for business mathematics, but I guess not. The present article doesn't now cover the material I'm referring to, but I'll give a shot at adding it. And it's more than just a course... it's what the vast majority of mankind (IMHO) thinks of as "math" -- arithmetic with commercial applications. Believe it or not, they don't even know what trigonometry is. Lou Sander 12:11, 14 January 2007 (UTC)
I added three short paragraphs to business mathematics, thereby (IMHO) plugging a minor hole in our coverage. Lou Sander 13:39, 14 January 2007 (UTC)
No objections to what's there currently. I just want to reiterate the point that we need to keep clear the distinction between "arithmetic with commercial applications" and "commercial applications of arithmetic". The former is not, IMO, an interesting way of categorizing anything; the latter might be. --Trovatore 02:27, 15 January 2007 (UTC)

Precision weighted

I came across this math stub and if anyone at the wikiproject would be interested in cleaning it up a bit. Or I can AFD it if it's not a real thing.Static Universe 19:30, 14 January 2007 (UTC)

It's not a cleanup, it's a complete rewrite, though there is little to rewrite. I speedied it for now as nonsense. Recreation should not be a problem.Circeus 20:13, 14 January 2007 (UTC)
Yeah, I was kind of understating it calling it "cleanup," but thank you. :) Static Universe 02:39, 15 January 2007 (UTC)

Mathematical analysis

The history in the article on mathematical analysis sounds suspect to me. At least it is very different then what I have been taught. I have tried bringing this up on the discussion page, but no were provided. Is anyone, or does anyone know a scholar in the history of mathematics who might take a look at it. I am reluctant to simply remove what is there because I myself can not say for wrong. Thenub314 20:58, 9 January 2007 (UTC)

To which portions of the History section are you referring, in particular? Are you suspicious of the claims made for the "Kerala School" in India? All of the Indian stuff? The "method of exhaustion" (Greece) is solid.
I agree that the bit about India is poorly written. Some of it doesn't even make sense. But I think the claims about actual mathematical discoveries in India are mostly right. The most controversial claim that has been made for the "Kerala School" is that Newton (and/or Leibniz) got his ideas from those guys. But this article doesn't appear to be making that claim. DavidCBryant 21:18, 9 January 2007 (UTC)
I may be correct, it just wasn't able to find any references that supported this point of view. But I should mention that my references are just the 2-3 math history books I own and the the MacTutor mathematics history site. But the fact the MacTutor history site did not claim so much was true, and gave a healthy list of references, togehter with the fact it never came up in my classes in the history of mathematics, made me suspect it. The things that I found particularly strange is the claims about derivatives and Rolle's theorem existing in 12th century india and term by term integration by 14th century. The information about infinite series, continued fraction and trig all seems to be spot on, and is quite amazing. But I just can't find refereed source that supports these claims. Thenub314 14:11, 16 January 2007 (UTC)
I'm trying to add references to the article when I can. If you have references and want to rewrite the paragraph about mathematics in India by all means go ahead and do so. I'm not certain that every bit of Indian historical information in the article is accurate ... I just said it's "mostly right". So if you think the bit about derivatives, and integration, is not quite accurate, blow it out of there. Or write me something on my talk page citing the references you've looked at, and I'll take a stab at that one paragraph. DavidCBryant 14:44, 16 January 2007 (UTC)

Computing Pi

This article seems problematic to me. It might be in violation of the rule against how-tos. AfD, or can it be improved, or merged somewhere? --Trovatore 06:25, 13 January 2007 (UTC)

I'm surprised to find that there isn't a natural merge target. Pi#Efficient methods seems to be the current home for such information; much of it should probably be merged away from that long main article. Melchoir 07:06, 13 January 2007 (UTC)
This topic is already well covered by our article on π, by our history of numerical approximations of π, and elsewhere. Since this stub is spotty, poorly written, and under the wrong title ("Pi" should not be capitalized), I'd say PROD, and AfD if necessary. (I see no point in a re-organization discussion unless a competent champion volunteers to do the work.) --KSmrqT 07:23, 13 January 2007 (UTC)
Huh, I didn't notice it before, but that History of numerical approximations of π article has a lot of verbatim overlap with Pi#Efficient methods. That's a Bad Thing; surely someone can fix it? Melchoir 07:32, 13 January 2007 (UTC)
I agree that Computing Pi is not worth keeping on Wikipedia. I'm curious about the "rule against how-tos", though. I don't think I've run across that one yet ... would someone please point me to it? ("It's not that I want to break the rules," said Alice. "If only there weren't so many of them.") DavidCBryant 18:54, 13 January 2007 (UTC)
That would be WP:NOT#IINFO, under instruction manuals. Melchoir 19:18, 13 January 2007 (UTC)
A redirect to History of numerical approximations of π is a lot simpler than an AfD. By itself Methods for computing pi is a notable topic, and it is hard to maintain that the article is a how-to style manual.  --LambiamTalk 19:41, 13 January 2007 (UTC)
I think the redirect is a good idea. Oleg Alexandrov (talk) 19:56, 13 January 2007 (UTC)
Sure, I'd accept a redirect. And again, "someone can fix" anything on Wikipedia; I'm not keen on mythical beings.
The claim that any of these items constitutes a "how-to" manual and somehow breaks a "rule", like WP:NOT#IINFO, is debatable. Wikipedia has vast numbers of editors, and a correspondingly vast spread of opinions of what it is or should be. Take any opinion (including mine) as a thought to consider, not a commandment from God, unless it comes from Jimmy Wales. In the long run, common sense and consensus, trained by experience, are your best guide. In my opinion. ;-) --KSmrqT 05:02, 14 January 2007 (UTC)

I don't think computing π needs to be a how-to. It could include how-to stuff but also theretical stuff about computation of π. For example, if there's a theorem that says no algorithm can comute the π to within ε faster than thus-and-so, it could be included.

I think it's a worthy topic, and although the present form of the article is clumsy, it could be brought up to reasonable standards.

I've fixed the title; it's now the Greek letter and not the upper-case "P". Michael Hardy 02:22, 15 January 2007 (UTC)

Are you suggesting we need both articles, History of numerical approximations of π – which has a section Development of efficient formulaeand Computing π? There is a huge overlap. I think one article covering the history as well as current efficient methods should be enough. Size is currently not an issue.  --LambiamTalk 11:22, 15 January 2007 (UTC)
Postscriptum. There is also Software for calculating π, Machin-like formula and List of formulae involving π#Efficient infinite series.  --LambiamTalk 11:34, 15 January 2007 (UTC)

The idea was not to make a how to(I'm sorry if it seems that way), it was to organise all the forumlas on the main Pi page . As it is, they are spread through-out the page. I find the "Calculating pi" section to be much cleaner now. The formulae section is large and alot to sift through right now. In my opinion the most important sections (Geometry, Physics,...) should be preserved and the rest (Analysis, Miscellaneous formulæ, ...) moved to appropriate pages (computing π, List_of_formulae_involving_π). Deathbob 02:15, 16 January 2007 (UTC)

Smarandache-Wellin number

I put Smarandache-Wellin number up for deletion; AfD discussion is here. —David Eppstein 20:59, 15 January 2007 (UTC)

Misner space

Could someone have a look at this? The article's derived from a popularization, and I'm not even sure this is an exact solution to GR or a piece of topology. Septentrionalis PMAnderson 23:11, 17 January 2007 (UTC)

I've trimmed it right down to something minimally verifiable: can someone who knows something about this expand it? -- The Anome 02:20, 18 January 2007 (UTC)
Is it really a good idea to take all that stuff out? It made some (little) sense before. Now it is a total mystery. JRSpriggs 08:18, 18 January 2007 (UTC)

Margin of error FAR

Margin of error has been nominated for a featured article review. Articles are typically reviewed for two weeks. Please leave your comments and help us to return the article to featured quality. If concerns are not addressed during the review period, articles are moved onto the Featured Article Removal Candidates list for a further period, where editors may declare "Keep" or "Remove" the article from featured status. The instructions for the review process are here. Reviewers' concerns are here. Kaldari 06:16, 18 January 2007 (UTC)

Odd bug in <math> processor.

Yesterday I was entering a formula that involved the expression z to the (2 to the n) power. I got a very odd result ... the <math> processor did not return an error (big red "failed to parse"), but the graphics engine that converts <math> to png images wouldn't work, or something, so that all I saw on a "show preview" was the raw TeX code, without the <math></math> tags around it. Oh – it also knocked the graphics interface out of commission entirely, not just on the line where I had the stacked superscripts, but throughout the rest of the page, as well. (I was using Firefox under Linux when this happened).

I finally figured out what the problem was by firing up my other browser, Konqueror, which rendered the other formulas OK, but failed on the one line that included z to the (2 to the n) power. That's why I suspect the graphics engine (it sort of gave up under Firefox, but Konqueror got a better result).

Anyway, I have a few questions. Is there a better place to report this problem? Some sort of technical support group, or something? And is there a central repository of information about bugs in wiki-TeX, where newcomers can learn about this sort of thing without having to hack through it on their own? Thanks! DavidCBryant 15:01, 18 January 2007 (UTC)

We have bugzilla for reporting bugs. They should be filed under 'mediawiki extensions.' --Sopoforic 17:06, 18 January 2007 (UTC)
The HTML "ALT" text for math images is the raw TeX code; you can look at it in Firefox by selecting "Properties" when right-clicking on a math image like this one z^{2^n}\ . Maybe your browser just hadn't loaded the math PNGs and so was displaying the ALT text. Do you have a reproducible example of the bug? CMummert · talk 17:17, 18 January 2007 (UTC)
I can see the image just fine in your message, CMummert. I'll go back to the article I was working on and see if I can reproduce the problem. I don't generally right-click on images, but now that I've looked more closely I see that I've got an option "block images from wikimedia..." I suppose that I might have selected that option inadvertently. Maybe it was load-related ... as I mentioned, Konqueror got most of the images, just not the one image with z^{2^n} in it. Sometimes when I run a search on Wikipedia it tells me to use Google or Yahoo instead. I guess that happens when the servers are under stress. Could there be something in the network OS that limits the generation of images when CPU cycles are getting scarce? That image generation process has got to be computationally expensive. Anyway, thanks for the feedback, both of you. DavidCBryant 19:13, 18 January 2007 (UTC)
I've been seeing a lot of random image loading failures lately, which especially impacts PNGs from <math> markup. These should (almost) all be cached, so I don't know where the failure is; I assume it is a server hiccup of some sort. --KSmrqT 22:45, 18 January 2007 (UTC)
This is a known bug; refresh and it'll work fine. IIRC it is something to do with NFS and access times. — Preceding unsigned comment added by 58.163.151.30 (talkcontribs)

Opposite (mathematics)

The page Opposite (mathematics) might need some attention from any mathematicians. It was found in Special:Ancientpages, and could probably be turned into a redirect, or even deleted. --Montchav 16:53, 8 January 2007 (UTC)

I merged it into opposite. - grubber 05:52, 21 January 2007 (UTC)

A few polygons for deletion

I've nominated Hectagon, Pentacontagon, and Tetracontagon for deletion since Decemyriagon was deleted. You can find the discussion here. --Sopoforic 02:25, 22 January 2007 (UTC)

Merging Ramanujan summation?

It looks like Ramanujan summation and Ramanujan's sum are about the same, or very closely related, topics. Should they be merged? -- The Anome 12:55, 22 January 2007 (UTC)

I don't see the connection. The first article refers to a method of assigning a value to divergent series – that's probably something like Cesaro summation, although the article doesn't explain it very well. Is this one of those "Ramanujan mysteries", where people think anything he wrote down has to be important, but nobody else has figured it out yet?
The second article describes finite sums which cannot possibly diverge. DavidCBryant 14:35, 22 January 2007 (UTC)

I don't see how you could possibly merge them; the topics are not remotely similar. Michael Hardy 22:44, 23 January 2007 (UTC)

Triangle

I am having an argument with an anon at Triangle about what should be included in that article and what not. Comments would be welcome at Talk:Triangle#What should be included. Oleg Alexandrov (talk) 03:17, 24 January 2007 (UTC)

Set at AID

The article Set is up for nomination at the Article Improvement Drive. It's such a core topic in Mathematics that I'm surprised it's not at GA status already. CloudNine 14:46, 21 January 2007 (UTC)

Its nomination certainly has my support. Iotha 18:11, 24 January 2007 (UTC)

A couple of questions

I'm working on a couple of articles for mathematical problems, and I'd like some opinions on a couple of issues. First, I'm not quite sure what I should do when stating the problems. They're old enough that I can quote the original statement of the problem. Assuming that the original statement is clear enough, would it be a good idea to quote it directly, rather than trying to come up with my own wording? Second, regarding solutions: in Kirkman's schoolgirl problem, I've got a copy of an arrangement that solves the problem. Would the article benefit from listing this solution? It doesn't really add anything, from a mathematical standpoint (except proving that there is a solution, I guess), but perhaps a reader would be interested in it. I do intend to add more information to it once I get a few things via ILL, but should I add the solution in the meantime? --Sopoforic 23:37, 23 January 2007 (UTC)

It's a nice article, Sopoforic. I think examples and solutions are good to have. How long is the solution? If it's not too long, I'd add it. Oh – are you sure you want all those red links? I don't suppose there's any real rule about it, but I usually try to introduce no more than one red link in a new article, and then only if I intend to write the red-linked article fairly soon. DavidCBryant 23:59, 23 January 2007 (UTC)
IIRC, the style guide says to put redlinks whenever it'd be useful to have that information linked, and when it is probably possible to write an article on that topic. I'm thinking of writing up one or two of those, and it doesn't really hurt to leave them. But I should probably de-link the title of Ball's book in the refs.
The length of the solution? Well, an arrangement that solves it is just seven sets of 35 characters, so it's not much. The solutions that I have that explain how to arrive at this (or, better, proving how many different solutions are possible and things like that) are quite a bit longer. Ball's book gives a solution in a couple of pages which I can probably summarize and include.
I was really more concerned with the first part. I've written up a bit on Archimedes' cattle problem at User:Sopoforic/Sandbox, which I'm planning on copying into the article space once I've got a bit more added to it, but I'm not sure how I should state the problem. If you'd give your opinion on that, I'd be most grateful. --Sopoforic 01:14, 24 January 2007 (UTC)
A bit more info on this: I'm pretty sure I've found an English translation (out-of-copyright) of the 22 couplets that make up the statement of the cattle problem. It seems to me that it'd be nice to include this in the article, but what I've got written now is surely clearer in terms of the mathematical meaning of the problem. Further, a 44-line poem may make the article a bit long for small gain. Should it be added to the article? Or perhaps this is a time when wikisource should be used. I'm not really sure. Comments are welcome. --Sopoforic 01:53, 24 January 2007 (UTC)
I would add the solution to Kirkman's problem, as an aid to the reader; Archimedes' poem belongs in Wikisource (and a prose version might be better, unless the couplets are more accurate than usual for verse translations.) Septentrionalis PMAnderson 19:36, 24 January 2007 (UTC)

Giving credit for articles translated from the Wikipedia's of other languages

I translated Halley's method from French to English. My source was fr:Itération de Halley. So I just informally put a link to it in the article, saying "*[[:fr:Itération de Halley]], French original". The original author Lachaume (talk · contribs), asked me (at User talk:JRSpriggs#Halley's method) whether I should not be using a template. Is there a template for giving credit to sources on other Wikipedias? JRSpriggs 07:00, 25 January 2007 (UTC)

I don't think that there is such a template. Wikipedia:Translation/*/How-to has a template, but I think that it's meant for coordinating a translation effort, rather than giving credit. --Sopoforic 07:50, 25 January 2007 (UTC)
There are the templates Template:German, Template:Italian, Template:Polish, and so on, but it seems there is no template for French yet. Go figure. (NB: Template:French redirects to a navbox template.) See Category:Interwiki link templates or Category:Citation templates. Lunch 07:53, 25 January 2007 (UTC)

I didn't know of any template, but I think probably there should be a little more detail than just an interwiki link. At Prime minister of Italy I put a note in the References section pointing to the version I translated and stating the date it was retrieved. --Trovatore 07:54, 25 January 2007 (UTC)

Thanks. I will change it to follow your model, Trovatore. JRSpriggs 12:00, 25 January 2007 (UTC)

Articles listed at Articles for deletion

Uncle G 12:02, 25 January 2007 (UTC)

Elementary mathematics

I think we really need some cleanup to be done on our articles on elementary mathematics. We put so much work into the articles on more obscure areas of mathematics, leaving our basic articles, the ones which are probably most viewed, neglected. Just by going to five random articles on elementary topics, I've basically either redone the opening paragraph or done serious work to all of them, as they were incomplete, incoherent, or misleading (see [1], [2], [3], [4], and [5]). —Mets501 (talk) 03:08, 25 January 2007 (UTC)

It's good that you are interested in editing these articles. For some reason, the more elementary articles tend to be the ones that lead to the most contentious editing. That may be why others stay away from them. CMummert · talk 03:25, 25 January 2007 (UTC)
I suspect it's due to the elementary articles being the most likely to be edited by a non-math person, or by a math person who has not yet gone into many of the advanced topics, which can lead to contentious editing (such as whether a trapezoid has only one set of parallel sides or at least one set. --Carl (talk|contribs) 14:47, 25 January 2007 (UTC)
Yes, most likely. They are also the most vandalized and edited, so it is harder to keep them stable. —Mets501 (talk) 14:57, 25 January 2007 (UTC)
Amen. I, too, had the experience of writing what I thought was a nice article on an introductory topic, which was promptly blanked by a clueless kid. I view the difficulty of editing and patrolling such articles as one of the more discouraging aspects of WP. This is why I've tried to follow the various proposals and efforts at defining "stable versions" and the accompanying editorial oversight boards.linas 05:50, 26 January 2007 (UTC)
I approach elementary articles timidly because they are difficult to write well. When I edit a more advanced article, I can use a sentence or two to orient the general reader and warn them off, then get down to business for the hard-core "mathematically sophisticated" reader. So-called "elementary topics" often aren't. What I mean is that they may first be met in early years, but a full treatment can draw on demanding foundations and lead to more sophisticated areas. Consider counting. This is something very young children learn and enjoy, but a full mathematical discussion should include the Peano axioms — a university-level topic, and might also consider the natural number object of category theory — a doctorate-level topic. It is already challenging to write well for young readers only, and considerably more difficult to write for graduate students at the same time!
And, as other have observed, since everyone "knows" (more correctly, thinks so!) about an "elementary" topic, everyone feels free to "improve" (actually, disrupt) the article. Primitive readers mess up the advanced delicacies, and advanced readers often lack sensitivity for young readers. Ah, the joys of Wikipedia! --KSmrqT 05:59, 26 January 2007 (UTC)

series field in {{cite book}}

There is now a "series" field in the {{cite book}} template, as the following example illustrates. CMummert · talk 03:52, 26 January 2007 (UTC)

Mumford, David (1999). The Red Book of Varieties and Schemes. Lecture Notes in Mathematics 1358. Springer-Verlag. doi:10.1007/b62130. ISBN 354063293X. 

{{cite book | last = Mumford | first = David | authorlink = David Mumford | title = The Red Book of Varieties and Schemes | publisher = [[Springer-Verlag]] | series = Lecture Notes in Mathematics 1358 | year = 1999 | doi = 10.1007/b62130 | isbn = 354063293X }}

This is good news. I cite a lot of books with {{cite conference}} but I think {{cite book}} would work for most of them and this gives a good reason to switch. Thanks! —David Eppstein 05:01, 26 January 2007 (UTC)
Notice by the way the very nice tool available at http://diberri.dyndns.org/wikipedia/templates/ which can generate book templates. Oleg Alexandrov (talk) 05:49, 26 January 2007 (UTC)

Zariski surfaces

Due to the recent banning of Dr. Piotr Blass, I have put his primary contribution to mathematics, the Zariski surface up for deletion as its sources are questionable, and the contributions made by Dr. Blass to the page also have some issues. Seeing as barely anyone knows what a Zariski surface is, I am bringing it to attention here to try and see what should be done.—Ryūlóng () 01:51, 18 January 2007 (UTC)

ROFL we edit conflicted while I was composing my own version of this request. Yes, the creator and main contributor to this article has been sitebanned for persistent vanity and disruption. Dr. Blass claims to have named the concept of a Zariski surface and we non-mathematicians would would appreciate if specialists weighed in about whether this page meets site standards for retention. Respectfully, DurovaCharge 01:55, 18 January 2007 (UTC)

Piotr Blass does not appear to be the initial auther of the article, from the edit history. Richard Borcherds does so appear. Michael Hardy 01:05, 21 January 2007 (UTC)

It would be nonsense to delete it. At most it should be semi-protected. Charles Matthews 12:19, 22 January 2007 (UTC)
Piotr Blass is now on Wikipedia:Deletion review/Log/2007 January 24, with a new draft article. --Salix alba (talk) 23:25, 24 January 2007 (UTC)
AfD again. --Salix alba (talk) 08:36, 25 January 2007 (UTC)
Hi, I've started a basic fact dump for the "Ulam Quarterly" journal. As yet, I dont have an opinion on whether the journal would satisfy our notability criteria, but would appreciate any input by academics in the field. John Vandenberg 05:03, 27 January 2007 (UTC)

Something is odd with the categories system

I noticed something odd with the categories system. Take for example the article Maximum modulus principle. It is categorized in Category:Complex analysis as expected. However, if you actually visit that category, the article is just not there. Same for Argument principle, Antiderivative (complex analysis), etc., which are categorized in Category:Complex analysis but don't show up in the category itself. Anybody else noticing the same thing? Oleg Alexandrov (talk) 05:49, 26 January 2007 (UTC)

Seems to be some caching problem. I edited Maximum modulus principle, hacked on the cat, reverted myself, and now it shows up. linas 06:00, 26 January 2007 (UTC)

I've seen the same problem for the last week or so with Category:Graph products. It's only showing two articles, but there are several others with that category that are not shown. —David Eppstein 06:04, 26 January 2007 (UTC)

See also /Archive 21#A bug?. And I also had the problem with another file, but it went away when I moved an improperly located inter-wiki link down after the category. It seems to go away when you edit the file. JRSpriggs 07:25, 26 January 2007 (UTC)
It looks like saving the articles caused the category links to be updated. Saving the category did not seem to do the trick I looked at bugzilla briefly but didn't see anything. CMummert · talk 13:56, 26 January 2007 (UTC)
The articles that should be in Category:Graph products are: Cartesian product of graphs - Hedetniemi's conjecture - Lexicographic product of graphs - List of mathematics categories - Rooted product of graphs - Vizing's conjecture . Hmm. CMummert · talk 14:04, 26 January 2007 (UTC)
I reported it as a bug on bugzilla. CMummert · talk 14:10, 26 January 2007 (UTC)
Thanks! That's great! Oleg Alexandrov (talk) 03:32, 27 January 2007 (UTC)

The whole category system is vastly inferior in virtually all respects to the system of topics lists. Michael Hardy 21:07, 26 January 2007 (UTC)

I would disagree in the strongest terms. :) Categories are "bottom up" approaches, where each article is categorized independently of other articles, and a list of all categorized articles is automatically generated. "Bottom up" approaches work much better on Wikipedia than top-down approaches, like creating a list, where you need an expert to regularly and go through tons of articles and add list them in the appropriate list (that almost never happens, and this approach can't scale for millions of articles).
OK, lists and categories are actually complementary. Luckily we are not forced to choose between one or the other. Oleg Alexandrov (talk) 03:32, 27 January 2007 (UTC)

product rule

Maybe some of the really elementary articles should be on the watchlists of more mathematicians. Some idiot added to product rule a proposed "alternate proof". Those parts of the "alternate proof" that were valid were no different from the proof that was already there. But after saying f(x) = u(x)v(x) the "alternate proof" section said:

By hypothesis, f'(x) = u(x)v'(x) + u'(x)v(x),\,

and went on to rely substantially on that "hypothesis". I deleted it, and rebuked its author rather harshly---I imagine someone's going to accuse me of violating the "assume good faith" rule, but I think anyone who adds what purports to be a mathematical proof to an article should understand that which is secondary-school pupils are expected to learn about what proofs are. Michael Hardy 21:07, 26 January 2007 (UTC)

logarithm

In logarithm, I wrote:

The quantity logb(x) is a function of both b and x, but the term "logarithmic function" in standard usage refers to logb(x) as a function of x while b is fixed. Thus there is one logarithmic function for each value of the base b (which must be positive and must differ from 1).
Viewed in this way, the base-b logarithmic function is the inverse function of the base-b exponential function.

At talk:logarithm someone is disputing this and thinks my impression of what a logarithmic function is must have come from one book which I failed to identify. Perhaps others here can talk some sense into him (or into me, if need be). Michael Hardy 23:55, 26 January 2007 (UTC)

I am not disputing that statement. It is correct. Please see the Talk:Logarithm. —Mets501 (talk) 03:46, 27 January 2007 (UTC)

Most wanted redlinks

While updating User:Mathbot/List of mathematical redlinks, I made a list of redlinks which show up more than once in math articles. It is available at User:Mathbot/Most wanted redlinks (sorted by number of times each link occurs). Some of those might be worth filling in. Oleg Alexandrov (talk) 00:17, 28 January 2007 (UTC)

Nice. I was going to suggest something like this sometime :-) --C S (Talk) 01:20, 28 January 2007 (UTC)
BTW, I've had occasion to bump into editors who don't seem to realize red links are important. I left some comments to this effect at the talk page for Wikipedia: Red link. Perhaps somebody can help out with cleaning up that page. At the moment, some of the things are kind of confusing. For example, while a careful reading shows that red links are useful and should not be blindly removed, some people apparently read the part that explains that broken red links (ie. those leading to deleted pages or misspellings) should be removed and think that means all red links are broken.
Since WikiProject Mathematics uses red links in such a crucial systematic fashion, I think it would be good to modify that guideline (or whatever it is...) to mention this kind of use by WikiProjects. --C S (Talk) 01:25, 28 January 2007 (UTC)

Quadratic disambiguation

Formerly, Quadratic redirected to quadratic equation.

This was inappropriate in many of the contexts that linked to it. For example, Gyro monorail has "the stability quartic must be factorised into a pair of quadratic terms"; John Muth contains "Herb Simon had shown that with quadratic costs...", and algebraic function has "of a parabola, a quadratic algebraic function in x". The quadratic equation is not relevant to any of these.

I have made a disambiguation page at quadratic. But because there are many different, albeit related uses of "quadratic", it would probably be better if the links to the quadratic article were changed to link to more specific meanings: quadratic function, quadratic polynomial, or whatever.

-- Dominus 17:38, 28 January 2007 (UTC)

I've categorized the various kinds, as the list was a bit long. Also, I removed some of the entries, as some were redirects to things already in the list. Check it out and see if I have categorized them appropriately. - grubber 23:23, 28 January 2007 (UTC)
I just fixed a few of the links to quadratic ... it was fun. From the quadratic page I just hit "What links here" in the "toolbox" and started working through the list. Today I learned, for instance, that the Brits call vacuum tubes "valves". Fascinating! Oh – it just occurred to me. Isn't "quadratic disambiguation" when a dab page points to another dab page? Is there a rule against that?  ;^> DavidCBryant 13:01, 29 January 2007 (UTC)
Americans called them "valves" also, long ago. It's because they allow current to pass through in one direction, but not in the other. -- Dominus 21:03, 29 January 2007 (UTC)
That kind of work can be very satisfying sometimes. A while back I went around and disambiguated all the links to Red Hook. Most of them were actually referring to Red Hook, Brooklyn, but not all. I found out that H.P. Lovecraft lived in Red Hook, Brooklyn. What a surprise! -- Dominus 21:06, 29 January 2007 (UTC)
Is there a rule against a disambiguation page pointing to another disambiguation page? Not that I know of. I have seen it once or twice. Some words are used for so many different things that you need to have an overall disambiguation page with many entries and one of them points to another disambiguation page which separates the mathematical usages. JRSpriggs 08:07, 30 January 2007 (UTC)
This is odd. I was working through "What links here" when I ran across this dab page, which points to this dab page. It's self-referential (that is, quadratic itself is an example of second-order disambiguation). Did somebody do that on purpose?  ;^> DavidCBryant 11:26, 30 January 2007 (UTC)
Good job all, the nicest disambig page I've seen in a long while. --Salix alba (talk) 08:55, 30 January 2007 (UTC)

Feb 2007

This is the archive file "Wikipedia talk:WikiProject Mathematics/Archive 22". It is for February 2007.

Articles listed at Articles for deletion

Uncle G 10:54, 29 January 2007 (UTC)

It wouldn't hurt to have some intelligent people comment on the above AfD, since the first several comments were written by silly gullible people. Michael Hardy 23:40, 29 January 2007 (UTC)

The AfD was closed with a resolution of keep. --KSmrqT 20:21, 1 February 2007 (UTC)

Ancient pages

Out of curiosity, I made a version of Special:Ancientpages just for math articles: User:CMummert/Oldpages. It lists articles on Mathbot's list whose last edit was in 2005. There are no articles on Mathbot's list older than that (except for one redirect page, but I think I fixed that). CMummert · talk 04:53, 1 February 2007 (UTC)

List of mathematics articles are not Mathbot's pages. They were there long before mathbot or me were around. Oleg Alexandrov (talk) 05:13, 1 February 2007 (UTC)
Point taken. CMummert · talk 05:18, 1 February 2007 (UTC)
So the list shows that the vast majority of articles are edited quite a bit, although of course those edits could be trivial or vandalism. Interesting. Oleg Alexandrov (talk) 15:44, 1 February 2007 (UTC)
I was pleasantly surprised. The median age, by the way, is Dec. 21, 2006, and over 70% have been edited since Nov 1, 2006. CMummert · talk 16:49, 1 February 2007 (UTC)

Modularity theorem

For some time the article modularity theorem had the incorrect title Taniyama–Shimura theorem, a name invented by an editor who wrongly thought that was what the Taniyama-Shimura conjecture was called when it was proved, and never used by mathematicians. This has been fixed on the English wikipedia, but unfortunately this mistake was copied to wikipedias in many other languages. So the corresponding page in the following languages needs to be fixed: Català Deutsch Español Français Italiano עברית 日本語 Português Русский Suomi Tiếng Việt 中文 (There are links to the pages in these languages at modularity theorem.) R.e.b. 19:45, 1 February 2007 (UTC)

Infinite monkey theorem FAR

Infinite monkey theorem has been nominated for a featured article review. Articles are typically reviewed for two weeks. Please leave your comments and help us to return the article to featured quality. If concerns are not addressed during the review period, articles are moved onto the Featured Article Removal Candidates list for a further period, where editors may declare "Keep" or "Remove" the article from featured status. The instructions for the review process are here. Reviewers' concerns are here. LuciferMorgan 04:54, 2 February 2007 (UTC)

User:Farever, who apparently created his/her account for the sole purpose of nominating this article for FAR, has stated a kind of vendetta against the article's existence. This would appear to be a misuse of the FAR process. Is there a way it can be "speedy" closed? --C S (Talk) 06:13, 2 February 2007 (UTC)

Recreational mathematician article for deletion.

See Wikipedia:Articles for deletion/Ed Pegg, Jr.. Oleg Alexandrov (talk) 16:23, 31 January 2007 (UTC)

The AfD was closed with a resolution of keep. (After the stub was expanded there was no dissent.) --KSmrqT 18:21, 4 February 2007 (UTC)

Nearly orphaned article

I found number spiral a complete orphan---no other pages linked to it at all. I did a few small copy-edits and put a link to it into another article, and added the "number theory" category. Perhpas others here can figure out which other articles should link to it or other categories it should be in. It would also benefit from an illustration and perhaps other additional work. Michael Hardy 23:11, 4 February 2007 (UTC)

Somebody linked Ulam spiral to it.--70.231.149.0 01:23, 5 February 2007 (UTC)
I believe number spiral fails the notability guideline's requirement of multiple independent nontrivial references, so I nominated it for deletion. Discuss at Wikipedia:Articles for deletion/Number spiral. -- Jitse Niesen (talk) 01:38, 5 February 2007 (UTC)

If it's not kept, I think it should be merged into Ulam spiral, perhaps with comments comparing and contrasting the two, and probably in terser and more efficient language than what is now in this article. Michael Hardy 02:06, 5 February 2007 (UTC)

Factorization

We really need to merge polynomial factorization and factorization; most of the article factorization is in fact on polynomial factorization, but it is treated more basically. Should we merge polynomial factorization into factorization, or merge most of the stuff in factorization on polynomial factorization into polynomial factorization? —Mets501 (talk) 04:11, 5 February 2007 (UTC)

Although polynomial factorization is certainly a kind of factorization, a merge in either direction would be unhelpful. Each topic has a great deal to be said about it, and neither should be burdened with the baggage of the other. If anything, factorization should be expanded in other ways. --KSmrqT 05:23, 5 February 2007 (UTC)

Problem with HTML entities

Yesterday I was poking around through some W3C tables when I ran across a couple of HTML entities (&thetasym = #x03D1 and &weierp = #x2118) that were new to me. So I added them to the table of symbols in Fropuff's user space, and they showed up fine: ϑ and ℘.

Today the Weierstrass "p" symbol ℘ still works OK for me, but I get an ugly little hook for the "\vartheta" symbol that I should be able to produce by coding ϑ (this ought to look like {\scriptstyle\vartheta} – yesterday it did, and today it doesn't). I figure it has to be in my browser somewhere. I'm running SuSE Linux 9.3, and I'm using Firefox 1.06 (yeah, I should upgrade Firefox, but it's kind of a pain to do, and I haven't gotten around to it). I did shut the browser down and restart it in the interim, so that's probably how I lost the glyph for ϑ, but I don't understand how that could happen. Oh – I also have my Wiki-preferences set to render all math expressions as PNG's.

Anyway, I'm curious if other people have any insight into this phenomenon. I also think I'm starting to understand the problem with in-line <math></math> expressions a little better. Please take a look at the following line in this message.


{\displaystyle\vartheta} \quad {\textstyle\vartheta} \quad
{\scriptstyle\vartheta} \quad {\scriptscriptstyle\vartheta} \quad
ϑ 
{\displaystyle\wp} \quad {\textstyle\wp} \quad
{\scriptstyle\wp} \quad {\scriptscriptstyle\wp} \quad

Anyway, if everything were working right, there should be five copies of each of the symbols I'm talking about on the preceding line, in four or five different sizes. I only see three different sizes through my browser, but one of them (the {\scriptstyle} size) looks about right for rendering in-line symbols. Does it look that way to you? I'm especially curious what it looks like to Windows users. Should there be something more about different ways of rendering math symbols in the style manual for math articles? Thanks! DavidCBryant 17:36, 4 February 2007 (UTC)

Both symbols look ok to me, in Camino. They are bolder and more upright than the png math symbols, and each of the html symbols is larger than two of the corresponding png math symbols and smaller than the other two. —David Eppstein 17:56, 4 February 2007 (UTC)
All work for me. Although Fropuff's table includes TeX invocations, it's a tiny subset of all the symbols one might wish to use. Compare to my table, which includes HTML entity names (underlined) and MathML/Unicode names. --KSmrqT 18:29, 4 February 2007 (UTC)
I am using the latest version of Firefox now; and the last of the five thetas looks very crudely drawn compared to the other four. JRSpriggs 06:23, 5 February 2007 (UTC)
Looking at them with my Internet Explorer, the last of the five in each group just look like rectangles. JRSpriggs 06:27, 5 February 2007 (UTC)
Thanks for the feedback. Are you using Windows XP, JR? "Crudely drawn" on the fifth one makes sense, since that's a font rendering, as compared to a graphic image (PNG) for the first four. I've done enough digging around on my own machine to convince myself that the problem is not really in my browser. It's buried deeper, in the font engine ("xft") for Linux. Oh, joy. Something else to learn about.  ;^>
Thanks for the big table, KSmrq. My system renders most of the symbols OK, up to about 0x'2900'. Past that I mostly get little square symbols that contain the four hex digits buried in the Unicode string. The "vartheta" string is anomalous (for me) because it's just 0x'03D1', a fairly low value, but it still renders badly. I guess I have to locate my LaTeX/Amsmath fonts and get them configured so that "xft" can find them. DavidCBryant 12:39, 5 February 2007 (UTC)
Squares appearing instead of the characters has nothing to do with which browser is being used - it is just a matter of whether an appropriate font including those unicode characters is installed. JPD (talk) 13:07, 5 February 2007 (UTC)
Not to put too fine a point on it, JPD, but it's not only a matter of installing the fonts. With most browsers, there's also a font configuration tool. So if you have two different fonts installed that can both render a particular Unicode glyph, your browser is going to select one of those ... and it may not be the one you'd rather see.
Anyway, I've got my ϑ problem straightened out now. I found fairly simple instructions on this web page, which may be of help to other Linux users. I installed about 50 new fonts (~ 7 MB) by following the instructions ... KSmrq's table looks better now, although I still have a significant hole between roughly 0x'2900' and 0x'02A00'. DavidCBryant 04:59, 6 February 2007 (UTC)
We are expecting the beta release of the STIX fonts "Real Soon Now", but meanwhile I find that one font, Code2000 fills almost every hole. --KSmrqT 08:56, 6 February 2007 (UTC)

To DavidCBryant: I am using: Windows 2000, version 5.0 (Build 2195: Service Pack 4). I do not understand fonts, so all I can say about that is that I use: Verdana, style regular, size 10, script western. JRSpriggs 05:38, 6 February 2007 (UTC)

Hoaxing

One zero one (talk · contribs · deleted contribs · nuke contribs · logs · edit filter log · block user · block log) is editing math and physics related articles and (I think deliberately) introducing errors. They are not so easy to spot, see this edit for example. Such things are much more worrisome than plain vandalism. Something to watch for. Oleg Alexandrov (talk) 04:23, 5 February 2007 (UTC)

84.92.224.122 (talk · contribs · deleted contribs · edit filter log · WHOIS · RDNS · RBLs · http · block user · block log) did something similar at General relativity and elsewhere — changing the values of physical constants. JRSpriggs 05:46, 6 February 2007 (UTC)

Jacobi rotation

I think this should be merged with Givens rotation because it's the same. See e.g. Golub/van Loan "Matrix Computations" --Mathemaduenn 12:55, 7 February 2007 (UTC)

Yeah, they're the same thing. In the context of eigenvalue computations, they're usually known as Jacobi rotations, and they're otherwise usually known as Givens rotations. To quote Golub and van Loan, "Jacobi rotations are no different from Givens rotations, c.f. Section 5.1.8. We submit to the name change in this section [Jacobi methods for the Symmetric Eigenvalue Problem] to honor the inventor." You might add a {{merge}} tag to the Jacobi rotations article. Lunch 23:46, 7 February 2007 (UTC)
Perhaps you have not read the articles. Both are planar rotations (rotations of a two-dimensional linear subspace of a vector space), but the Givens rotation is a one-sided transform chosen to introduce a single off-diagonal zero in a matrix without regard to symmetry, while a Jacobi rotation is a similarity transform chosen to produce a pair of zeros in a symmetric matrix. The computations are completely different. Each article does refer to the other. Sometimes the names are used interchangeably, but the distinction is well worth keeping. I believe if you actually read the excellent Golub and Van Loan book, which is cited, you will find no contradiction.
One possible source of confusion is that when we have a real symmetric matrix like
M =
\begin{bmatrix}
 2.6&0.2&-0.7&-2.4\\
 0.2&-4.4&1.9&2.2\\
 -0.7&1.9&4.2&-2.5\\
 -2.4&2.2&-2.5&-1.7
\end{bmatrix} ,
then a Givens rotation of the last two rows that zeros the −2.4 entry in the last row, when applied from the left, will (by symmetry) act in transposed form from the right to zero the −2.4 entry in the last column.
 Q =
\begin{bmatrix}
1&0&0&0\\
0&0&-0.28&0.96\\
0&0&-0.96&-0.28
\end{bmatrix}
 Q M =
\begin{bmatrix}
 2.6&0.2&-0.7&-2.4\\
 0.2&-4.4&1.9&2.2\\
 2.5&1.58&-3.576&-0.932\\
 0&-2.44&-3.332&2.876
\end{bmatrix}
 Q M Q^T =
\begin{bmatrix}
 2.6&0.2&2.5&0\\
 0.2&-4.4&1.58&-2.44\\
 2.5&1.58&0.10656&3.69392\\
 0&-2.44&3.69392&2.39344
\end{bmatrix}
We can systematically work in this fashion to reduce M to tridiagonal form, but we cannot diagonalize it. If we zero an element on the subdiagonal with a Givens rotation, the zero is immediately destroyed when we complete the similarity transform. So we must choose our rotation as described in the Jacobi rotation article to actually get zeros. Of course, a side-effect of that is to create a "bulge", destroying our tridiagonalization.
\begin{align}
 M &{}=
  \begin{bmatrix}
   2.6&0.2&0&0\\
   0.2&-4.4&1.9&0\\
   0&1.9&4.2&-1.2\\
   0&0&-1.2&2.4
  \end{bmatrix} \\
 Q &{}=
  \begin{bmatrix}
   1&0&0&0\\
   0&1&0&0\\
   0&0&0.8944272&-0.4472136\\
   0&0&0.4472136&0.8944272
  \end{bmatrix} \\
 Q M Q^T &{}=
  \begin{bmatrix}
   2.6&0.2&0&0\\
   0.2&-4.4&1.69941&0.84971\\
   0&1.69941&4.8&0\\
   0&0.84971&0&1.8
  \end{bmatrix} \\
\end{align}
We are not surprised; otherwise we could find roots of polynomials of arbitrary degree using radicals, which is impossible. --KSmrqT 03:05, 8 February 2007 (UTC)
The transformation both use is the same, but you're right, they're applied for different effects. In context, Givens rotations are only applied one-sided whereas the Jacobi rotations are applied as a two-sided similarity transform. Sorry, I guess a merge isn't in order. (But I do wish you wouldn't just up and delete my comments.) Lunch 03:52, 8 February 2007 (UTC)
I have not knowingly deleted your comments, and would only delete any comments in extreme circumstances, such as severe spam or vandalism. However, this bug has bitten repeatedly, so I'm (sadly) getting used to the complaint. I never get the slightest warning in advance, only irate responses on the (so far) unpredictable occasions when it occurs. (Sigh.) Maybe one day the software will get fixed, or I will find a reliable workaround. Meanwhile, please, restore anything you wish that mysteriously disappeared. --KSmrqT 06:57, 8 February 2007 (UTC)
(No worries. It happens.) Lunch 18:53, 8 February 2007 (UTC)
Have you tried not hitting the "back" button after the preview, as you say you often do? I'd be curious if that solves the problem. There's not really a need to do that anyway. --C S (Talk) 10:06, 8 February 2007 (UTC)
I don't think that this is the common use of the term "Jacobi-Rotation". That's all. Maybe my first comment was to short. So a book source should be added. The content of Jacobi-Rotation can also be used to improve Jacobi eigenvalue algorithm. But it's only a suggestion. --Mathemaduenn 13:53, 8 February 2007 (UTC)
Do you mean this isn't a common use of the term "Jacobi rotation"? In that case, isn't Golub and van Loan good enough to establish that usage?
Or do you mean this isn't the common use of the term "Jacobi rotation"? If so, what else have you seen this term used for?
Thanks, Lunch 18:53, 8 February 2007 (UTC)
The use is "It is the same as Givens Rotation." and how KSmrq said these names are used interchangably. Also Golub van Loan defines Givens Rotations and uses Jacobi Rotation in the same manner. It's a Rotation in the plane spanned by e_k and e_l. --Mathemaduenn 09:02, 9 February 2007 (UTC)

Various issues

A few things I'd like opinions on:

First: are we (we, anybody) using the {{Maths rating}} template? I come across articles all the time without it on them (like Polygon, for example, which I guess is top-class or high-class importance, or whatever the word is we use). I could add this to articles (talk pages, rather) when I notice it's missing, but I don't want to do it if it'd just be a waste of time.

Second: should we have a category for math problems? I don't mean like 'integrate x^2', but things like Archimedes' cattle problem, Kirkman's schoolgirl problem, Doubling the cube, etc.

Third and fourth: It seems that Mathbot hasn't removed bluelinks from the math articles listed at WP:MST since august. It's not a big deal, but should I just do it by hand? Also, there are some things listed that I don't quite know what to do with: take, for example, Mud cracks (listed on Wikipedia:Missing_science_topics/Maths18. MathWorld says that cracks in mud tend to cross each other at right angles--the Mud Cracks article on mathworld redirects to Right Angle. Mathworld cites some sources to support this, too. Should wikipedia mention that in Angle? Or maybe in Mud? (Imagine: a project mathematics banner on Mud). It seems like it'd be hard to justify putting it in there. On the other hand, it's vaguely interesting (for some definition of interesting) and apparently verifiable. What should be done?

Suggestions, as always, will be appreciated. --Sopoforic 01:41, 8 February 2007 (UTC)

Second: I don't see why not. Article topics should be categorized by what they are in addition to the field of science into which they fall, and not just in math. Melchoir 00:23, 9 February 2007 (UTC)

Re the rating template: I can imagine them being used to prioritize effort, but I don't know that anyone does use them in that fashion. One other use is to show our recognition of well written articles or improvements to articles by giving them better quality ratings. I have at least added a few more of these templates (and filled out the fields in some uncategorized ones) since seeing your note here. —David Eppstein 02:53, 9 February 2007 (UTC)

Replies:
  1. According to Wikipedia:WikiProject_Mathematics/Wikipedia_1.0 anybody can grade articles with the {{maths rating}} template as they see fit. I'm sure the guys working on it would appreciate the help.
  2. I think something like Category:Famous mathematics problems would be a fine category.
  3. You have to ask User:Oleg Alexandrov about this one. He runs mathbot.
  4. If anywhere I think it should be mentioned in the Mud article. That article wouldn't warrant a math category because of it though. In short mud cracks shouldn't be listed at WP:MST.
-- Fropuff 04:56, 9 February 2007 (UTC)
All right, I'll put the rating template on articles when I notice them. Regarding the category, probably just Category:Mathematics problems or Category:Problems or something would be enough--if they weren't famous (or at least notable), we wouldn't have articles for them. I'll leave a note for User:Oleg Alexandrov if he doesn't chime in before I get a chance. And, finally, I'll see about adding a note to Mud (once I decide whether it's worth adding, anyway). Thanks for the replies, everyone. --Sopoforic 17:19, 9 February 2007 (UTC)

Template:Hilbert's problems

What do we think about: Template:Hilbert's problems. Given that we have Category:Hilbert's problems, do we think the template is useful? Paul August 19:27, 8 February 2007 (UTC)

Some people prefer template navigation. But if we keep it, we should do one of two things:
The ancient debate of navational boxes vs. categories. Navigational boxes do not add any information, but as PMAnderson notes some people find them user friendlier (less mouseclicks.) Now if all those boxes where properly marked up being navigational boxes, people who dislike them could hide them. (P.S. Maybe there should a way to automatically generate those boxes through the articles included in a certain category.) —Ruud 20:03, 8 February 2007 (UTC)
There is a class="messagebox standard-talk collapsible collapsed" command which gives a template the little show/hide box. See {{WikiProjectBanners}}. But is that enough to fix this? Septentrionalis PMAnderson 00:12, 9 February 2007 (UTC)

I agree with Septentrionalis. I would prefer an other article template that simply pointed to the main Hilbert problems article. These problems are so diverse and their numbers are so uninformative about the actual content of the articles that I don't see the navbox as useful. —David Eppstein 23:03, 8 February 2007 (UTC)

Agree. If I saw that box at the bottom of the page, I wouldn't know what to do with it. I know what the problems are (generally), but I wouldn't know them by number. There's no real benefit in providing easy navigation if the user can't tell where they're going. The table present in Hilbert's problems is much better for navigation. A notice like {{otherarticles}} should be fine (though it ought to point to Hilbert's problems, not the category, in my opinion). --Sopoforic 02:51, 9 February 2007 (UTC)
It does both; it has two arguments; see Template talk:otherarticles Septentrionalis PMAnderson 06:01, 9 February 2007 (UTC)

The new version of Template:Hilbert's problems is much more palatable. Paul August 16:22, 9 February 2007 (UTC)

Yeah, but I still question whether it adds any value. The only use cases I can think of are: you accidentally stumble upon an article for one of Hilbert's problems, and realize that you want to look at problem #17, but don't feel like clicking the link to Hilbert's problems; or, you want to navigate through all of them to read about them, but don't want to have an extra window/tab open to click them from Hilbert's problems. The first is unlikely; the second is possible, but I don't know whether it's going to be important enough to justify an otherwise-meaningless template. On the other hand, space at the bottom of the article is cheap: this isn't doing much harm, anyway. --Sopoforic 17:15, 9 February 2007 (UTC)
Possible uses would be quickly opening each article in a tab or reading the introduction of all the Hilbert problems by using popups. Some people find this useful, some don't. —Ruud 19:57, 9 February 2007 (UTC)
If you're opening them in tabs or reading with popups, you can do it from Hilbert's problems just as easily. But, like I said, it isn't really doing any harm, either. --Sopoforic 23:50, 10 February 2007 (UTC)

What can be done about "Exponential smoothing"?

Exponential smoothing has been around for a long time. Although it appears to be on a legitimate topic, it is one of the most poorly written articles. So badly written in fact, that the difficulty of fixing it probably deters people from even trying. As EconStat (talk · contribs) said, "I feel really sorry to see poor work like this on Wiki.". It is too far out of my field for me to fix it. If no statistician is willing to fix it, perhaps we should put it up for deletion. What do you think? JRSpriggs 06:46, 5 February 2007 (UTC)

Why not just rewrite it as a short stub, since the current content is quite odd. Eventually someone will decide to expand it from there. Deletion is usually reserved for topics that don't deserve an article even if it was written well; there is no deletion criteria for articles with bad writing. CMummert · talk 14:03, 5 February 2007 (UTC)
I'm willing to take a stab at a complete rewrite, since I have extensive experience with time series. I notice that moving average already exists as a financial topic. Although financial applications of time series attract a great deal of attention today, the statistical techniques for improving "signal to noise ratio" are more widely applicable than that. For instance, someone with limited daily temperature data for a particular location might base his "forecasts" for this year's daily highs and lows on a moving average of actual temperature data from the past two or three years. DavidCBryant 16:52, 5 February 2007 (UTC)

I've done some (very badly needed!) cleanup. More is needed. Michael Hardy 21:53, 5 February 2007 (UTC)

Thanks, Michael. I hope you and the others can stand to wade through it. JRSpriggs 05:54, 6 February 2007 (UTC)
OK, I just dumped a complete rewrite in there. It's not comprehensive, but at least it's a reasonable start. Please take a look and polish it up a bit. Thanks! DavidCBryant 00:50, 10 February 2007 (UTC)
Thanks, David. It looks much better. Now that you have fixed it up, I expect more people will jump in with changes. JRSpriggs 06:32, 10 February 2007 (UTC)
I put a comment on the weighting on the talk page Talk:Exponential smoothing#Problems with weighting. JRSpriggs 03:51, 12 February 2007 (UTC)
Many thanks to Michael and David for cleaning it up. --A bit iffy 07:53, 12 February 2007 (UTC)

question about definitions of objects

Some time ago I was looking at free algebra's for a paper I was doing in Universal Algebra and I looked at the wp page on the subject. The definition was a sort of "abstract algebraic" or "ring theory" definition, and it got me to wondering about definitions of mathematical objects on WP. A free algebra could be defined in the language of UA, of category theory, or probably in other ways. How does one know which way to go for a WP page on a mathematical object? If someone wanted, they could easily go to dozens of articles and add in UA or category theory or whatever definitions of everything from logic operators to who knows. I was thinking of adding this question to the Math MoS, but I figured it would be ok to add it here. I think that the answer should be incorporated into the MMos, or somewhere in a policy guideline.

To answer my own question a bit, in many cases the most naive definition is best, who wants to mess with this stuff in an arithmetic page. On the other hand there are some cases where almost all of the research in a subject is done by logicians or computer scientists or whatever, so the definition they use is best. But, this is a type of WP imperialism, as many pages are defined with the CS way of looking at it due to the high number of editors with CS backgrounds, frustrating other potential users. Sometimes the subject can be safely split into how different fields look at it (such as Combinatorial game theory and Game theory), which can also help. Smmurphy(Talk) 02:15, 13 February 2007 (UTC)

It depends on the level of the expected reader of the article. The article on natural numbers should be much more elementary than the article on groupoids. But there is no limitaton on the space that we can use to describe a topic, so any relevant and notable definition can be included, at least in a subsection. For example, Peano axioms gives a categorical definition as a subsection. CMummert · talk 02:30, 13 February 2007 (UTC)
I am having this daydream of future WP wars where category theorists approach every math article and add a category theory definition (or move that definition to the top), while putting new research into a new category, "math which is not yet sophisticated enough to warrant a category theory approach." Computer scientists counter marking articles as "math which doesn't and will never have real world applications," and universal algebraists add a reference to Burris & Sankappanavar to dozens of articles. Smmurphy(Talk) 02:46, 13 February 2007 (UTC)

Recently translated article, needs expertise

Could someone have a look at Gauss-Lucas theorem. It needs to be put into context and made understandable to a general audience. − Twas Now ( talkcontribse-mail ) 05:04, 13 February 2007 (UTC)

categories for deleteion

Category:Claude Shannon, Category:Norbert Wiener are up for deletion at WP:CFD 132.205.44.134 00:45, 15 February 2007 (UTC)

Some missing topics

I have a short list of missing mathematics topics. I have tried to find all relevant links to similar articles but I would appreciate if someone could have a look at it. Thank you. - Skysmith 13:44, 16 February 2007 (UTC)

There is a list of requested articles at Wikipedia:Requested articles/Mathematics. You should consider adding these to that list. CMummert · talk 19:25, 17 February 2007 (UTC)

New math articles

Just as a reminder to perhaps newer people, there are two pages where one can see what is going on with the math articles. First, Jitse's very versatile Wikipedia:WikiProject Mathematics/Current activity, and then my own User:Mathbot/Changes to mathlists which justs lists articles added and removed from math lists.

There is a lot going on in math on Wikipedia, with at least five (or more like ten) articles created daily (my unscientific guess is that we are creating articles at a much faster rate than either PlanetMath or MathWorld). There is a lot of work however in making sure that those articles have proper style, are correct, notable, and mathematical. So, if you have time, taking a look on those pages every now and then could be a good thing. Cheers, Oleg Alexandrov (talk) 22:28, 10 February 2007 (UTC)

I looked through several new articles this morning and I see two reasons why we may be getting so many of them.
  • People who speak English as a second language want to write articles about mathematicians with whom they're familiar. I noticed several articles about Russian mathematicians which (to judge by a conspicuous lack of the word "the", and by the names of the contributors) were probably written by Russian authors.
  • People who don't understand mathematics well enough to look for a topic related to the word they're curious about. For instance, there was a new article for "leptokurtotic", plus an older stub article for "leptokurtosis". We already had redirects for leptokurtic and platykurtic in Wikipedia, and an excellent discussion of fourth moments at kurtosis. So I was able to clean out a couple of useless articles by coding some new redirect pages (for leptokurtotic and leptokurtosis and platykurtotic). Those words look like poor English usage to me, but they're present on the web, so people look them up on Wikipedia. And if the words aren't here … Voila! A new article is born. DavidCBryant 17:07, 11 February 2007 (UTC)
That's why we need more people to look over recent additions. Bad articles are caught best when caught early. :) Oleg Alexandrov (talk) 23:48, 11 February 2007 (UTC)
I keep on noticing new patterns as I work through the lists of new articles. Here are a few I've been seeing recently.
  • Ideas that are "out there", but that accrete templates/stub notices/category tags without being deleted. Probability control is a "good" example. I count 28 words in the original article, and 107 words in the moss this rolling stone has gathered during its brief career.
  • Articles that discuss mathematical concepts from a non-mathematical point of view. Here are two (Self-referencing doomsday argument rebuttal and Negative probability) that I found particularly amusing, in case anyone else wants to have a look. I took the "probability" tags off both of these so they can go swim around as philosophy and/or "pseudophysics".
  • Redirect pages that have category tags stuck on them. The categorization crew is having a field day.
  • Real solid new math articles. Supersingular K3 surface is a good example. Thankfully there are quite a few of these. DavidCBryant 14:15, 17 February 2007 (UTC)
Yep, a good chunk of those articles should either not exist as written or are not properly categorized so they are often not math. Oleg Alexandrov (talk) 16:27, 17 February 2007 (UTC)
Here's another odd situation. 56 (number) has existed since 13 December, 2003. Because of a recent unfortunate edit, its entire revision history has been disconnected. That revision history is now associated with another article, 56 (game). The article about the card game was actually created on 16 February, 2007, but it now has 3+ years of history associated with it, even though it's really only 2 days old. How am I supposed to straighten something like that out? I guess it's not a huge deal, but it doesn't seem right, somehow, that an article should be divorced from its edit history. DavidCBryant 14:34, 18 February 2007 (UTC)

The story started with an anon blanking 56 (number). Then in a few days somebody else saw the blank page and created an article about the game 56 (note that the IP of the guy who blanked, 71.233.129.128, is very similar to the IP of the guy who created the game, 71.250.232.151, although that's probably a coincidence).

I moved back 56 (game) to 56 (number) and reverted to the pre-blank version. The game itself doesn't seem notable enough to have its article. Oleg Alexandrov (talk) 16:13, 18 February 2007 (UTC)

About images

I've already done some hunting through Help:Images and other uploaded files and some other associated pages, and I haven't found an answer yet, so I'm asking a question here. Is there a recommended maximum size for image files embedded in a Wikipedia article? If not, should there be?

Here's why I'm asking. I was reviewing the list of new math articles when I ran across Shallow water equations. It's an interesting article. And it has a very nice animated GIF embedded in it, which illustrates waves in a bathtub evolving over a period of time. The only problem is that the graphics file (Image:Shallow_water_waves.gif) is roughly 7 Mb in size. On my machine the animation takes about 30 seconds to run. So I'd need a data transfer rate of ~250 Kb per second to view this animation in real time, and I don't have that kind of a connection.

I'm just wondering if there's some sort of convention for a really big graphics file like this one. I think it's a nice animation, especially for people who have high-speed internet connections. But roughly half of all the internet users are still using dial-up, AFAIK. Wouldn't it be nice to link to an animation file like this one as a separate article, with a caption describing the file you're about to download? DavidCBryant 17:31, 14 February 2007 (UTC)

You might grab a single frame from the animation to use as a still image in the article. You could then put in a wikilink to the animation with a note about its size. As a further enhancement, if you're super-duper motivated, you could recompress the animated GIF into Ogg format.
Nice addition to the article, BTW. Lunch 19:50, 14 February 2007 (UTC)
That animation could certainly be clipped to the first 2 (maybe 3) splashes without losing any content. Tesseran 05:47, 17 February 2007 (UTC)
I think you should insist that images which load slowly be put in a separate file with a link to it. That way, if you know your connection is slow you can avoid clicking on it and just read the text of the article. But if your connection is fast or you are willing to wait, you can click on the link and see the image. JRSpriggs 07:45, 17 February 2007 (UTC)

Boy's surface kills my browser due to huge animations even with a high-bandwidth connection. I think the first animation on the page adds a lot to the understandability of the surface, but it should probably be significantly reduced in size, and one of the editors of that page seems to feel that if one animation is good more must be better. —David Eppstein 08:06, 17 February 2007 (UTC)

Same thing here David, it killed my browser too. I also have a high-bandwidth connection. Definitely needs to be reduced in size.--Jersey Devil 08:21, 17 February 2007 (UTC)
Thanks for all the responses. Apparently there is no convention about big images. Or at least, nobody has heard of it. I guess I'll try asking in a couple of other fora. Oh – I should clear up some apparent misconceptions. Lunch, I didn't make up any graphics files. The shallow waves animation is from Dan Copsey. I was wrong when I said half of all internet users are on dial-up – I checked some statistics on that, and it's more like one-fourth (23% in the U.S., currently). Interestingly, the total size of the graphics files I received on the Boy's surface article is just 2.0 Mb, or about 29% of the size of the splashing water animation. But the biggest picture there (1.2Mb) is served at the top of the article. At least Dan Copsey had the good sense to put his little movie at the bottom, so a user doesn't necessarily notice that the big grapic is loading until he scrolls down the page. DavidCBryant 12:29, 17 February 2007 (UTC)
I've just done a heavy prune of Boy's surface I've cut out two of the visulisations and two sections devoted to visulisation of the surface. --Salix alba (talk) 18:39, 18 February 2007 (UTC)

Apologies?

Saying that the Project consists of "only suggestions" sounds apologetic. I think that starting a Wikiproject with an apology or disclaimer is probably a bad idea. The overall tone of the project does not sound heavy-handed. Have others reacted badly to the existence of this project? Many of the other WikiProejcts do not start their page with such caution.

Also, there was briefly an attempt to provide some kind of realistic status. It read:

Perhaps the greatest sign of distress in this WikiProejct at the start of 2007 is that of the five articles that are both FA and Top importance, three of them are biographies (See also the chart in Wikipedia:WikiProject Mathematics/Wikipedia 1.0). The other two articles are Polar coordinate system and Game theory, the latter of which contains not a single equation or diagram of a spatial nature. Surely, more of the non-biography articles in Category:Top-importance mathematics articles can be brought to FA status this year. Let us aim for the goal that some of those new (or restored) FA's contain equations.

This assessment seems fair and points in an interesting direction. Should it be put back? For perspective, you might want to familiarize yourself with WP:100K.--199.33.32.40 22:08, 4 February 2007 (UTC)

I strongly support a non-prescriptive approach to Wikipedia; and one of the things that make this project worthwhile is that it begins with one. See WP:PRO.
My opinion of WP:FA is far lower: it will promote essentially worthless articles like Daniel Webster, which is written out of Henry Cabot Lodge's artificial and dated exercise in biography. FA cannot exercise better judgment than its members', and its members have none. The current review of infinite monkey theorem alone will show this. Septentrionalis PMAnderson 22:57, 4 February 2007 (UTC)
I do not mean to be contentious, but even if the FA process sux, it is all we got. I would like to roast alive the monkey in IMT as badly as you. In my imagination, I can smell that acrid burning hair even as we...but I digress. To start off with such weak-willed verbiage as we do betrays a lack direction in our WikiProject. Wouldn't it be more motivating to just have a rousing "Let us get some FA-quality content secured" and try to ignore the gauntlet of inline-obsessed editors we have to go through to get there? We can make it if we just do the content-building and the inline refs, and respond to the feedback, no matter how unfamiliar or uncomfortable the demanding FA reviewer is with, say, first-semester calculus. We should encourage a positive, constructive attitude and, you know, pretend like the FA process does not sux. It is just a matter of determination, judgement and productive focus on our part.--199.33.32.40 00:35, 5 February 2007 (UTC)

Before you start changing the WikiProject page to state your desires for what the WikiProject should focus on, you should discuss it first on this talk page. After all, it doesn't seem like you've even participated enough in this WikiProject to get a sense of what the community thinks. Also, is there a reason that you apparently created a new account (User:Farever) and stopped using it? Keeping track of the different IPs is kind of annoying.

Speaking for myself, non-prescriptiveness is a good thing. If it distinguishes us from other WikiProjects, that'll all for the good. I believe the main purpose of this WikiProject is to improve mathematical coverage on Wikipedia. We all have differing ideas of what this means. Some may argue that this entails more FA mathematics articles, while others disagree. I personally wonder if the our time is most effectively utilized tweaking articles to make it through the FA process. There are bigger issues, e.g. fixing the elementary mathematics articles. --C S (Talk) 04:22, 5 February 2007 (UTC)

The anon does raise some good points about lack of FA quality articles for our most important articles. I second the comments about getting a login name, you will be taken more seriously with one. Over the last year I think there has been improvment in the general quality of our more important articles. The situation looks better when you consider our A-Class articles, better still when GA and B+ class articles are taken into account.
Personally I'm not too fussed about FA-class articles, it takes a lot of work to acheive and maintain and their are some systematic dificulties we face trying to gain that status: anything sufficiently advanced is likely to fail as the reviewers will find it hard; continued debates over citations; brilliant prose is not something mathematicians are trained in. I'd much rather see our top and high importance article gain B+ or higher quality so we have a good all round coverage.
One thing I've been thinking about is having some sort of formal process for an article to obtain A-class status. We could set our own criteria which reflects the needs of mathematical articles and a brief review process. --Salix alba (talk) 09:46, 5 February 2007 (UTC)
I agree that developing our own criteria for A-class articles would be a good idea. A recent discussion in Wikipedia: namespace has highlighted the fact that the vast majority of rated articles in the whole encyclopedia are rated Stub, Start, or B, while very few are rated B+ or A. This is certainly the case with the math project. The criteria don't require that A-class articles are perfect, only that they are very good, and each project is free to develop customized criteria for A-class articles (although the only one I could easily find is the Military History project). CMummert · talk 01:35, 21 February 2007 (UTC)

Cleanup main project page

I would like to mark Wikipedia:WikiProject_Mathematics/Motivation and Wikipedia:WikiProject_Mathematics/Proofs as historical and direct additional conversation from them to this page instead. I looked at them today and realized that they are still gaining new comments, even though the main project page seems to describe them as historical discusions. Any objections?

Also, the 2006 update is beginning to look a little old in Feb. 2007. I would like to add a 2007 update. What are the main issues that require attention this year? There have been several comments in recent weeks about improving articles on elementary subjects, so that might be a candidate for one. CMummert · talk 13:53, 5 February 2007 (UTC)

I think a better idea is to move the historical discussion to an archive page, e.g. .../Proofs/archive1. Keep some of the more recent comments (from the last several months). That way when the conversation starts getting long and involved it will be localized in one obvious spot, as I predict there will be long gaps in the discussion; otherwise, Werdnabot will shelve parts of it in different spots. It should also decrease repetitionin discussion. --C S (Talk) 14:34, 5 February 2007 (UTC)
The look of the project page could be improved. Wikipedia:WikiProject Molecular and Cellular Biology has a fairly clean look to it, and a minimum of fancy graphics, which should please Oleg. Work on elementary, top and high class articles are my suggestions for attention. Also WP:MATHCOTW seems to have very little activity of late, the last article chosen was in mid November. --Salix alba (talk) 14:25, 5 February 2007 (UTC)
When did Oleg get the reputation for not liking fancy graphics? :-) I would miss the 2002 retro look, but the page is starting to get unwieldy. --C S (Talk) 14:49, 5 February 2007 (UTC)
I guess Salix alba means this. I actually kept the graphics the anon put in, but reverted anon's modifications to the text part. That because I'd rather have one of us look through the page and decide how to reorder things than allow an anon coming out of the blue to do things. And no, I have nothing against graphics, as long the pretty pictures help in usability rather than just distract. Oleg Alexandrov (talk) 16:44, 5 February 2007 (UTC)

I cleaned up the page some. I like to put links at the side so that it is easier to start reading at the top. I don't dislike images per se but I don't see how the images in the newly-added nav box actually helped the page any. And they were too big. CMummert · talk 02:27, 7 February 2007 (UTC)

The nav box is great. The box currently includes links to the discussion pages on proofs and motivations. So it seems like you agree with my prior comments. Should we archive those pages (to subpages) and create clean versions, which can hopefully be managed in a more organized way? At this point, I also recommend everyone watchlist those pages, since it appears that discussion on those issues may be centered there. --C S (Talk) 13:25, 7 February 2007 (UTC)
I don't feel strongly one way or another about keeping the other two talk pages. There have been no comments on Motivation since 2005, so my instinct is to mark it as historic and list in with the talk archives of this page. The Proofs talk page should definitely be archived and cleaned up. CMummert · talk 13:56, 7 February 2007 (UTC)
The proofs and motivations subpages should really be moved into the Wikipedia talk namespace since they are, in fact, discussion pages. Whether we should mark them as historical or keep them open is debatable. Should these pages ever produce some sort of recommendations/guidelines we can put those in the Wikipedia namespace. -- Fropuff 23:32, 7 February 2007 (UTC)
There is some discussion for having discussion pages in the Wikipedia namespace: the village pump and reference desk. But if you want to move them I doubt anyone will revert it. CMummert · talk 04:38, 8 February 2007 (UTC)

I've just redone the project page in a two column layout[6]. The Nav box by CMummert caused a few layout problems so I've cut and pasted it for now and and hacked it a bit to make it work. Feel free to revert. --Salix alba (talk) 21:18, 7 February 2007 (UTC)

I like the new layout :-) Interesting how the (superb) animation of tesseract has become the unofficial logo ... only (minor) problem is that the sidebar is bigger than the main content, and will (hopefully) get bigger as more maths articles become FAs and GAs. Hmmm.... I seem to be putting (occasional) words in brackets a lot.Tompw (talk) 00:12, 8 February 2007 (UTC)
Perhaps, the graded articles material (good/featured articles) should go on a subpage. That way, future growth won't overwhelm the main project page. Also, if we are going to have a logo for this project (official or otherwise) perhaps we should vote on one. The tesseract animation is superb indeed, but I find animated gifs somewhat distracting. -- Fropuff 02:10, 8 February 2007 (UTC)
The new layout is problematic of narrow screens. The actual text content is in a narrow column about 2 inches wide on the left while the sidebar on the right is about 4 inches wide. I'll tweak it some.
Is there a non-animated image that could be used instead of the animated one? I'm not so sure that an image belongs here, instead of on the Portal. In my mind, the function of the project page is to gather together resources that help editors. CMummert · talk 03:19, 8 February 2007 (UTC)
I tried, but I couldn't get the two-column layout to work with a narrow screen. The image here (warning: advertising) is a screenshot that demonstrates the problem in firefox; it's worse in opera. So I added the new content (image, MCOTW, graded articles table) to the old version and reverted. If there really is huge demand for a two-column layout I won't fight against it, but I think that as long as the rest of WP is in single-column format our page should be as well. I'm sure I'm not the only person with a narrow screen. CMummert · talk 04:23, 8 February 2007 (UTC)


Erdős number categories up for deletion yet again

Wikipedia:Categories_for_discussion/Log/2007_February_9#Category:Erd.C5.91s_number_1

The discussion has been going on since Feb.9, so speak quickly or you may not get a chance to speak at all. —David Eppstein 07:23, 19 February 2007 (UTC)

Update: discussion was closed early today with a result of no consensus. The closing admin doesn't seem to have paid attention to our requests for more time so that WPM members could respond, but we did get quite a few responses in the short time available. —David Eppstein 23:41, 20 February 2007 (UTC)
We don't want to give the appearance of group-think by mobbing these discussions; there were probably enough comments by mathematics editors at the end. A more useful way to convince people of the notability might be to add additional published references to the Erdos number article. I would guess that some of the papers named there as "External links" were actually published. Once Erdos numbers are established as clearly notable, the categories are harder to argue against. Personally, I am neutral about the categories - individual articles are free to state the Erdos number of mathematicians whether or not they are categorized as such. CMummert · talk 00:07, 21 February 2007 (UTC)

I've refrained from these discussions, because I don't have a leaning either way. One thing that disturbs me is that it seems arbitrary to have a category for say, Erdos number 6 (which I think was actually created in between these CFD debates). Is there, for example, a cutoff typically used by social network researchers? --C S (Talk) 00:41, 21 February 2007 (UTC)

Six degrees of separation says that everyone is connected by six steps, indeed we find that the modal Erdos number is 5 and virtually all mathematicians (97%-ish) will have EN of 7 or less.[7] (P.S. debate now closed as no consensus) --Salix alba (talk) 07:56, 21 February 2007 (UTC)
Having co-authored a paper with someone is a much closer relationship than just knowing him/her. JRSpriggs 08:33, 21 February 2007 (UTC)
Closer still is co-authoring a book. As with buying a certain brand of automobile, a revealing question is, "Would you do it again?". The Mathematics Genealogy Project is also fascinating. But most of one's professional life comes after graduate school, and it is hard to document influences and connections. A broad web of co-author connections tells more than the Erdős number, and even that cannot show how much a researcher was influenced by reading Lagrange or Atiyah or Grothendieck.
We can admit, without prejudice, that the Erdős number is partly of interest as entertainment, perhaps a step up from "What's purple and commutes?" (An abelian grape.) Beyond that, it also serves to remind us to collaborate, whether as co-authors or merely as colleagues. Such encouragement is especially important for mathematicians, because by inclination and by necessity, we often work in solitude.
How do we explain that to the rest of the world? Wikipedia devotes more pages to sports and films and games and other forms of entertainment than it does to mathematics, so it would be churlish to deny us our fun. And like Playboy's other content (short stories, interviews), the Erdős number has social value. --KSmrqT 11:00, 21 February 2007 (UTC)
At the risk of being obvious, one's Erdős number is a status symbol, an indication of how well-connected one is within the mathematical community. JRSpriggs 11:50, 21 February 2007 (UTC)

Numerical digit

I just rewrote this article; please visit, improve the article, and offer comments. It's a vital article, so I think we should work to improve it to at least good article standard. --N Shar 20:25, 20 February 2007 (UTC)

If you are interested in getting some sort of assessment for the article, I would recommend first improving it, then putting it up for peer review, and finally nominating it for Featured Article status. But you should be aware that the criteria for featured articles may differ from the criteria that we ordinarily use to assess mathematical writing. CMummert · talk 20:43, 20 February 2007 (UTC)
Actually, I'm just looking for reassurance that I didn't completely ruin the article. --N Shar 20:59, 20 February 2007 (UTC)
The new article is a significant improvement over the previous version. CMummert · talk 22:40, 20 February 2007 (UTC)
Thanks. I'm still working on it; maybe I will nominate for peer review/GA after it gets some references. --N Shar 22:45, 20 February 2007 (UTC)

special characters

The articles Naive set theory and Subset use special math characters that show up as squares in IE 7. There are probably other articles like that. Can someone substitute the TeX math characters? Bubba73 (talk), 05:09, 15 February 2007 (UTC)

Or, you could join the civilized world and install a font or two. The STIX Fonts project will be releasing theirs soon, and Code2000 has long been available. This is no different than if you were reading an article involving Chinese or Arabic; you'd need fonts for those notations as well. --KSmrqT 06:39, 15 February 2007 (UTC)
It works fine for me with IE 6, so it may be an issue of some font not being installed. Looking at Wikipedia:Mathematical symbols, can you identify which characters don't display properly?  --LambiamTalk 06:35, 15 February 2007 (UTC)
A large number of those don't display correctly, e.g. the last four of Analysis, the last six of Arrows, and the last four of Logic. None of Sets are correct except the next to last one. Bubba73 (talk), 20:03, 15 February 2007 (UTC)
With Lucida Unicide, all of those display except the fifth and sixth delimiters. Bubba73 (talk), 02:13, 16 February 2007 (UTC)
Or switch to Mozilla Firefox as I suggested at Naive set theory. JRSpriggs 09:04, 15 February 2007 (UTC)
Sometimes I use Firefox, and they are OK there. But I mainly use IE 7. Many other people use that too. Bubba73 (talk), 20:04, 15 February 2007 (UTC)
No, it's a matter of an appropriate font being installed. Unless it is, it won't matter which browser you use. JPD (talk) 10:24, 15 February 2007 (UTC)
I did some digging around, and found this very helpful web page. Should we try to get some links to this worked into a Wikipedia article about MathML / Unicode / UTF-8 somewhere? DavidCBryant 16:43, 15 February 2007 (UTC)
I changed my main browser font to Lucida Sans Unicode, and now they display correctly. Other people have had the same problem. I don't know if this is the best solution, but it fixes that. My thanks to the users who helped. Bubba73 (talk), 20:43, 15 February 2007 (UTC)
Lucida Sans Unicode can fill many character gaps if you have it. Unfortunately, Microsoft restricts distribution, and Wikipedia is viewed with many browsers and operating systems. If you want to see how good your character coverage is now, I keep a page with hundreds (!) of mathematics characters, here. --KSmrqT 01:02, 16 February 2007 (UTC)
I have Lucida Sans Unicode, it must have come with my system. It fills in many of the gaps in math symbols. Farther down the page, though, most are still missing. And using that font changes the font of a lot of other websites. Bubba73 (talk), 19:17, 16 February 2007 (UTC)
Ok this is the first place I've seen a contemporary discussion about the display problems that I've been

long plagued by in WikiPedia. I've tried to find and implement and analyze solutions, but I'm at a loss, so I thought that by sharing in some detail my own experiences / results / efforts that I can help others understand, solve, or become aware of the difficulties. I appreciate the efforts of those who've taken the time to author what appear to be many fine technical pages on WikiPedia, I simply wish that many of them were usefully accessible to me. I have to believe that my IT/PC/Browser setup is representative of or better than that of most casual Wikipedia users, so I imagine that if I (and others here) are having such difficulties that the problem must be widespread and that the solution(s) are poorly known. Yet given the substantial quantity of well authored and similarly encoded technical pages on WikiPedia, it stands to reason that the authors must be aware of the appropriate guidelines, tools, techniques, and encoding / authoring techniques to create their pages, view them correctly, and have some 'quality assurance' expectation that most of their audience should be able to view their works with reasonable success and facility. However, if that's so, I've certainly missed finding "the instructions" as to how to repeat their successes! I've been impatiently waiting for the STIX fonts and FireFox 2.x for nearly a year hoping that maybe it was just a local font and rendering engine deficiency that I could clear up with those tools, but alas it's appearing unlikely to me that it's "simply" explicable and soluble by those two issues. I'm hoping that someone who does have mathematical (et.al.) symbol display mostly or wholly working with their browser can speak up and help answer what configuration(s) are beneficial to achieve that result. Though I've often seen FireFox lauded for superior MathML et. al. display versus IE6, I'm presently (and miserably) having the opposite experience. Using a "full" default install of WinXP, fully updated recent versions of FireFox 2.0.0.1 and MS IE 6.0.x, I'm unable to correctly see a great number of Wikipedia's mathematical symbols under FireFox and I'm missing a lesser but significant number of them on MSIE 6. Following the tips of users' comments here and elsewhere I've tried both FF and IE, I've installed the recommended TeX, MTExtra, Mathematica, MathML, et. al. fonts, I've experimented with changing my default encoding's font and size to several various choices including the installed Lucida Sans Unicode, et. al. I've enabled JavaScript, Cookies, Style sheets, and web site overrides of my chosen default fonts. I've reloaded the pages containing inappropriately rendered characters many times to judge whether anything I've done has made an improvement. ...For example, with this representative page:

I notice that under MSIE, even before installing non-default fonts, automatically loaded many PNG images to display graphic representations of symbols / equations, and by so doing that it got many of them correctly displayed. Whereas on the same system under FireFox, even after correctly installing numerous additional fonts, most missing characters are still displaying TeX-like escape codes in plainly visible "text code" and the rendering is neither invoking "png image loading" to display graphic representations of the symbols/equations (like MSIE is doing), nor is FireFox apparently able to or trying to render the symbols / codes via any of the installed MathMl / Unicode fonts et. al. ...For another example:

In FireFox, the above page correctly shows a couple of dozen of the symbols; most of leftmost ones are all OK; the bottom rows as well as most of the symbols on the right sides of all rows do not display correctly; instead I see what looks like character entity references as one would type them "in code". In MSIE, the page display is just about equally broken as it is under Firefox. It's showing a combination of empty box characters and textual character entity reference codes instead of most of the characters on the right and bottom side of that page. ...I've followed the instructions / suggestions at the below couple of sites to install new Windows fonts and have verified that they're installed and recognized / available to the browser(s) and system in general:

...I'm a developer myself and am not unfamiliar with XML, MathML, fonts, UNICODE, HTML, TeX, et. al., but despite several hours worth of googling, experimentation, and looking for Wikipedia pages on tips for using its Mathematical Notations with browsers, I have yet to find a solution or even consistent diagnosis for this seemingly fundamental and oft encountered problem. Even in the context of this Talk Page there's contradictory information about whether it's the fault of the browser, missing fonts, user configurations of browser fonts, et. al. If it were just a browser issue, I would expect that in either MSIE6 or FFox2 I'd have "mostly successful" experiences; I do not. If it was a missing font issue, I'd expect that having installed all the platform default as well as dozens of commended added technical / symbol / mathematical fonts would have mostly solved the problem; it has not. If it was mostly a local problem, I'd expect that most Wikipedia pages would look uniformly good / bad and act consistently; they do not; the following page displays much more successfully than the second following one:

If it was "mostly just my errant setup" I wouldn't expect to see evidences of other users reporting similar problems, so many contradictory hypotheses about the problems, and I'd have expected to find some kind of FAQ / guide suggesting "the standard configurations" that'd be working for most people who had followed suit. Another example:

...looks mostly bad and unrendered in FireFox 2, whereas on the same system, IE6 renders it mostly fine though it's clearly resorting to WikiPedia server-side provided png graphic renderings of the equations / symbols instead of using any local font. Another example, this looks to be an excellent and useful test matrix of characters / symbols:

On both MSIE6 and FireFox2 (cum MANY additionally installed technical font sets) the page's table is mostly absent correctly rendered symbols. A great number of them (but still perhaps well less than half) are properly rendered in FireFox. A significantly lesser number of them correctly render in MSIE6; mainly the first 22 rows from the top are mostly OK in MSIE, whereas most of the rest of the table is not rendered. If it was a local font issue, I'd expect relatively uniform "pass/fail" between the two simultaneously active browsers. Clearly from the quaternion WikiPedia page there must be, at least in THAT case, a different stylesheet or something Wikipedia is using to tell MSIE to graphically load many of the page's equations, whereas doing something different and more unsuccessful for FireFox. Does ANYONE have these pages mostly / fully working, and, if so, what's the secret, please?!

Overall I'd say that most work very poorly in FireFox, and the ones that work 'well' in MSIE are exclusively ones where, somehow, a graphical versus textual representation is provided 'server side' via Style Sheet or some other mechanism to cause MSIE to not even try to display most of the symbols / equations via local font or rendering technologies. Obviously that .png bitmap graphic approach leaves a lot to be desired (scalability, searchability, accessability, et. al.), but at least it's a visual "on screen" step forward wrt. total gibberish. It must be a choice that's not consistently or fully implemented server side, though, since many of the pages don't try to do that in MSIE and in such cases the result is no better than in FireFox. I haven't extensively experimented with this issue in LINUX, though I've encountered similar problems sufficiently often with FireFox/LINUX to suggest to me that there's nothing uniquely beneficial about LINUX's browser / fonts that makes it work much better than I've experienced under MS Windows. If anything LINUX tends to lack some of the more 'common' TrueType / UNICODE fonts that are 'often' available on MS Windows platforms, so OS platform doesn't seem to be the essential problem. —The preceding unsigned comment was added by 216.99.216.242 (talk) 09:10, 22 February 2007 (UTC).

(You were use *foo* for emphasis, rather than the wiki ''foo'', which conflicted with the wiki interpretation of a line beginning with "*" as a bullet point. Fixed.)
I have seen no feedback suggesting your ordeal is typical. Perhaps that means widespread satisfaction, or perhaps it means most give up in quiet despair. Given the amount of effort you have invested, we can certainly invest some ourselves to help you achieve success. I suggest we first concentrate on using Windows XP, Firefox 2.0, and one or two pages. To begin, please install a copy of BabelMap. We will especially use its "Tools>Font Analysis Utility..." (shortcut:F7) menu option, to show which installed fonts cover a chosen Unicode block.
While you do that, I'll give some relevant background. Mathematics display within Wikipedia is far from ideal, mixing several different techniques. Complicated equations imitate TeX:
<math>\int_a^b f(x)\, dx = g(x) + C </math>
\int_a^b f(x)\, dx = g(x) + C
These go through a process that produces a PNG image. So as not to overload the servers, the images are cached. Lately I've found that images of all sorts, not just equations, often fail to load. Since I haven't changed anything on my end since six months ago when this rarely happened, I assume Wikipedia is having technical difficulties. Standard browser behavior for a missing image is to display the alt content, which in this case will be the TeX input for the equation. Simple equations may (partly depending on user preference) generate HTML instead of an image.
<math>g'(x) = f(x)</math>
g'(x) = f(x)
This should always work. Special characters and more complicated equations force the PNG.
<math>g'(x) = f(x) \,\!</math>
g'(x) = f(x) \,\!
<math>g'(x) = \tfrac12 f(x)</math>
g'(x) = \tfrac12 f(x)
At present Wikipedia has no MathML support, so our best alternative is Unicode and markup. We can illustrate with a line from Wikipedia:Mathematical symbols:
'''Logic:''' {{unicode|&not; &and; &or; &exist; &forall;}} &amp;not; &amp;and; &amp;or; &amp;exist; &amp;forall;
Logic: ¬ ∧ ∨ ∃ ∀ &not; &and; &or; &exist; &forall;
On this line, the characters displayed on the left are produced by the text shown on the right. (Notice that on the right the ampersand is entered as &amp;, so the ampersand character is displayed, rather than used as an escape character.)
Only a small number of characters have HTML names like this, but any Unicode character can be produced in one of two ways. The first is as a numeric entity, like &#x22A2;. The second takes advantage of WikiMedia's UTF-8 support, allowing any character to appear verbatim, like . This particular character, RightTee, is covered by Lucida Sans Unicode, so if you have that font installed and if your browser is configured to use it, in principal it should display without trouble. However, it is not covered by fonts like Arial or Times New Roman, so some users may see a "missing character" glyph, typically an empty box or question mark. The fonts in my table are basically ordered by Unicode code point (numeric value), which means the further down you go the more exotic the character, and the less likely it will be covered. For example, Unicode includes a dedicated symbol, Cross, for the cross product, ⨯, code point U+2A2F [VECTOR OR CROSS PRODUCT]. BabelMap tells me it is covered by Code2000, but by no other font I have installed, including Lucida Sans Unicode. (This is why I so firmly recommend Code2000!)
Maybe this information will help a little. --KSmrqT 16:12, 22 February 2007 (UTC)

Another AfD

The article Checking if a coin is fair is up for deletion. People who read this page might want to take a look at it. DavidCBryant 14:59, 15 February 2007 (UTC)

The decision was to keep the article. --KSmrqT 15:19, 24 February 2007 (UTC)

More deletions

Felix A. Keller and Keller's Expression

Keller keeps adding himself and his unimportant and obvious expression to the page about e. He has done this at least four times since 2004. Now he has promoted himself and his expression to a pair of articles.

See Wikipedia:Articles_for_deletion/Felix A. Keller to discuss.

-- Dominus 16:51, 15 February 2007 (UTC)

Obviously, given that the links have turned red, the result was delete both. --KSmrqT 09:59, 22 February 2007 (UTC)

Importance

Some articles about individual mathematicians who were important in the development of math are rated as top importance, e.g. Leonard Euler and Gottfried Liebniz, or mid importance, e.g. al-Khwarizmi. But shouldn't all of those articles be rated as low importance, because who developed the concepts is not relevant to math, it is historical trivia, wikiproject mathematics should really only concerned with articles that focus on technical aspects of mathematics. Prb4 19:55, 15 February 2007 (UTC)

So, you're saying that these articles you mentioned above might be top-importance in some biography project, but not in a Mathematics project? I think I see where you're coming from. I guess it all kind of depends on what this Wikiproject really encompasses. –King Bee (TC) 20:02, 15 February 2007 (UTC)
The history of mathematics is an important component of mathematics. In many cases, the history says a lot about the mathematics itself. (The obvious example would be the Newton/Leibniz development of calculus.) Maybe you're saying that the history is fine, but the biography is less relevant to the math itself. Like the previous poster, I see what you're getting at, but I disagree. We should include key biographies in any list of important articles. VectorPosse 20:23, 15 February 2007 (UTC)
I think User:Pbr4 is referring to the "importance" field of the rating box appearing on some talk pages. This doesn't refer to the importance of the article to this project; it refers to the importance of including the article on a yet-to-be-made CD or DVD version of the encyclopedia. Presumably there would not be enough space for everything, so the importance field is supposed to help choose which articles to include. Interpreted this way, it makes sense for articles about Leibniz and Euler to be high importance — they are of high importance for making the DVD coverage similar to other encyclopedias. It is a historical coincidence that biographies of mathematicians are covered by the mathematics wikiproject. CMummert · talk 20:31, 15 February 2007 (UTC)
Historical coincidence? Well, I wouldn't quite put it like that. A lot of wikiproject members just find working on bios of mathematicians interesting, perhaps of relevance to the actual mathematics. I would say that editing mathematics and mathematical bios are often so complementary, e.g. the actual researching involved can be linked, that it makes sense things should be like this. --C S (Talk) 22:28, 15 February 2007 (UTC)
Technically importance does relate to importances within the specific project, and not for the CD or biographies as a whole. It is allowable to have difference imporance rating for different projects. coin flipping is one example with two different importances and theres others within the cross over with cyptography.
It is important to remember that we are writing an encyclopedia not a maths text book so historical information is a vital component. Actually I think haveing historical coverage is one of our unique aspects as history so so often neglected in mathematical texts. I learned must of my group theory not knowing in which century it was developed! Historical info can add context to the maths and helps show the development of the ideas.
We did spend some time trying to assess importance of the top 100 or so mathematicians and in some respect these are some sort of comparision with other mathematicains. Flawed yes, but a rough measure. There is also the field argument in the rating template and bios all have field=biography. At some point in the future, when the number of graded articles has grown, it may be possible to sperate out the mathematicians so we can have one list for strict maths articles and another for mathematicians. --Salix alba (talk) 00:26, 16 February 2007 (UTC)

I find this talk about 'historical trivia' to be actually offensive. What is more, the proposition that mathematics articles should be only about mathematics, narrowly defined, makes no sense in terms of the needs of the general reader; which is where WP aims, in principle. Further, I know from past comments that mathematicians themselves can find historical context helpful. Charles Matthews 19:31, 18 February 2007 (UTC)

I agree, although I would add that writing accurately about the history of mathematics is extraordinarily difficult compared to writing about mathematics. One reason is that writing about technical mathematics is more or less standardized, whereas I don't think that's true for history of mathematics.--CSTAR 19:54, 18 February 2007 (UTC)
I did some digging around to learn more about the Wikipedia:Version 1.0 Editorial Team (these are the guys trying to organize the contents of the CD version to which CMummert referred, above). You can see the list of "important" mathematicians the team has identified on this page. The list of "important" topics in mathematics is right here. DavidCBryant 16:17, 21 February 2007 (UTC)

A question about categories

I was reviewing Complementary sequences and noticed that the only math-related tag on the article was for the category "Elementary mathematics" (which seems strange, since Golay codes aren't all that elementary). Anyway, that got me curious about other topics associated with error correcting codes. I couldn't find any corresponding topics in the list of mathematics categories. So then I looked at several of the articles in list of algebraic coding theory topics and found that some of these are "math" articles (because they carry category tags like "finite fields") and some of them aren't (because they carry category tags like "error detection and correction").

So now I have a question. What's the preferred procedure in a situation like this? Is it OK to add another category to the list of mathematics categories? What if that category is likely to drag in a bunch of articles that aren't really math articles? Would it be better to add some more specific tag (like "finite fields") to some of the articles (in, say, "error detection and correction") that seem entirely mathematical? Frankly, I'm a little bit confused by the existing hodge-podge of "categories" on Wikipedia! DavidCBryant 17:58, 18 February 2007 (UTC)

There is no good answer to your question. Whether a given article belongs to a given category can be a subjective question, and whether a given article is a math article is also a subjective question.
I created the list of mathematics categories and I have mathbot add articles from those categories to list of mathematics articles so that we have a way of noticing and listing math articles. I try to be rather conservative about what categories to include in there, and categories which contain a lot of non-math articles usually don't make it in. I don't know if that's a good idea in the long run. Outside review of list of mathematics categories is very welcome.
If you feel strongly that a certain article should be in the list of mathematics articles you can either add it to a "mathematical" category as "defined" in the list of mathematics categories (then the bot will automatically list that article), or you could add that article directly to the list of mathematics articles (the bot does not remove articles from there, even if they are not in math categories, the bot just adds articles and removes redirects and redlinks). Oleg Alexandrov (talk) 18:12, 18 February 2007 (UTC)
OK, Oleg – thanks for the information. I ran across two categories that aren't on the control list for your 'bot, but that appear to have a great number of math articles in them. You might want to add "Category:Coding theory" and/or "Category:Information theory" to the list of mathematics categories. If you decide not to do that, then I'll try to make time to add the math articles in those two categories onto the list of mathematics articles. I looked through both categories for a little while, and found some articles that are already on the "math article" list, and others that are clearly math-oriented, but not on the list yet. DavidCBryant 00:43, 19 February 2007 (UTC)
I added Category:Coding theory to math categories. I don't feel comfortable adding Category:Information theory however. It has too much stuff which is not really math. And the category is generic enough that people may occasionally put odd stuff in it, and there's going to be more work to keep strange things from popping into the list of mathematics categories. Perhaps some of those articles could be categorized into "more mathematical" categories? Oleg Alexandrov (talk) 03:01, 20 February 2007 (UTC)

I've just done some cleanup on complementary sequences. Using an asterisk for ordinary multiplication, as if we were restricted to plain ASCII, is uncouth; we're not primitive troglodytes. Also, notice this difference:

N-1
N − 1

Michael Hardy 21:13, 19 February 2007 (UTC)

Thank you for working on it, Michael. My wife would not necessarily confirm your hypothesis: that I'm an actual example of Homo sapiens, and not a more primitive species of primate.  ;^> Sorry I didn't catch all the poorly coded stuff in complementary sequence the first time through, but after putting in about 75 or 80 of those non-breaking spaces (to make the big long vectors look better) I just got tired. There's only so much of that kind of stuff I can take at one sitting. DavidCBryant 23:47, 19 February 2007 (UTC)
No David, you ain't a troglodyte. Michael is a homo sapiens too, by the way, just one of grumpy subspecies. :) Oleg Alexandrov (talk) 03:01, 20 February 2007 (UTC)
The real troglodytes — Pan troglodytes. JRSpriggs 05:44, 20 February 2007 (UTC)

Oleg is mistaken as to which subspecies I represent. I'm a hothead, not a grump. Michael Hardy 20:39, 21 February 2007 (UTC)

Probability notations

Hi all! It would be a nice thing to try to set some rules concerning notation for the probabilty and expectation symbols. In the various probability/statistics articles I've seen at least three notations: P,E, \mathbb{P},\mathbb{E} and finally \mathrm{P},\mathrm{E}. Personally, I prefer the latter, as it's the accepted notation of the scientific community (sometimes the letters are bold, i.e. P and E but always straight). I have not seen nevertheless any guide that woud explain such a thing. Some article even go as far as to right Pr... Let's make a public discussion about this resulting in some agreement and guide for wikipedia math community. Amir Aliev 21:05, 21 February 2007 (UTC)

Consistency would be nice, but I dunno that there's a problem. I've seen almost all of those notations in print in various places (\mathrm{E},\mathbb{E},E and \mathrm{P},P,\mathrm{Pr},Pr). I can't remember whether I've seen \mathbb{P}, though. Lunch 21:17, 21 February 2007 (UTC)
\mathbb{P} gets used alot. The most consistant place I have seen it used is in financial mathematics to distinguish risk-neutral probability measure from the physical probability measure.Thenub314 00:43, 22 February 2007 (UTC)
Could you please some decent sources with P, \mathrm{Pr} or Pr ? Nevertheless, the fact is that we should pick only one notation. Amir Aliev 21:27, 21 February 2007 (UTC)
There are two extreme positions one can take with respect to notation conventions. One would be to have none. This means each article would be responsible for explaining the notation it uses (not a bad idea anyway). Another would be to standardize everything. The problem with the former is that it can confuse a reader browsing through related articles. The problem with the latter is mostly one of agreement: people use different conventions and many have strong feelings about one over another.
We should have one notation for all as wikipedia as a whole is one piece of work, not the collection of individual articles. Otherwise, it will be disastrous for the reader. Moreover the convenience of the reader certainly outweights the convenience of the writer. Amir Aliev 19:05, 22 February 2007 (UTC)
It's certainly true that five different probability theory books will use five different notations. So how do we declare one as being better than another? The few notation conventions that WikiProject mathematics has laid out in its style guide seems to be relatively uncontroversial since they agree with a majority of sources out there. (The glaring exception seems to be the use of "Dih" for dihedral groups. I don't have any idea about that one; the discussion for that decision must have taken place before I started hanging out around here.)
So this leads to a more general question. Is there some magic number that tells us what percentage of textbooks have to agree on a notation before we declare it here as a convention? Alas, for probability theory, the answer to that question may not be good news since there seems to be a lot more disagreement in that discipline, even for basic concepts like P and E. VectorPosse 22:49, 21 February 2007 (UTC)
Well, then we should organize some sort of election, for example every interested user citing some book on probability (conceivably the one they like most) and then we will count the notations in this books. It would be very interesting for me because I still don't know enough modern works from the respected authors with notation other than straight P and E. Amir Aliev 19:44, 22 February 2007 (UTC)
The universal convention I have seen for dihedral groups is Dn, and I recall no discussion ratifying the Dih notation. Sometimes things sneak in that should be removed; this is such.
Wikipedia as a whole depends more on collegiality and consensus than on conventions rigorously enforced. Sometimes we're lucky, and find almost universal agreement in current practice. For example, the ratio of circle circumference to diameter is denoted by π. Sometimes most of the English-speaking world agrees, even if others do not. For example, the unit interval including 0 but excluding 1 is denoted by [0,1). (Elsewhere, [0,1[ is used.) A great deal of mathematics notation seems to fall into these two categories. After that, things get more complicated. Sometimes an older convention has largely been displaced by a newer one, but it is important to know both to read the literature. For example, proofs once often ended with Q.E.D., but now commonly end with a block character. Sometimes different subfields or conceptual schools prefer their own convention. For example, algebraic topologists may write Z2 where number theorists would write Z/2Z. Finally, things get simple again, with "conventions" that are used by one editor alone; these we discard.
The editor of an article may not be aware that different conventions exist. When we know, our cardinal rule is to be kind and clear and helpful for the reader. A nice example of this can be found in Fulton & Harris, Representation Theory: A First Course, ISBN 978-0-387-97495-8. On page 100 we find "Remarks on Notation", which says:
A common convention is to use a notation without subscripts or mention of ground field to denote the real groups:
O(n),   SO(n),   SO(p,q),   U(n),   SU(n),   SU(p,q),   Sp(n)
and to use subscripts for the algebraic groups GLn, SLn, SOn, and Spn. This, of course, introduces some anomalies: for example, SOn R is SO(n), but Spn R is not Sp(n); but some violation of symmetry seems inevitable in any notation. The notations GL(n,R) or GL(n,C) are often used in place of our GLn R or GLn C, and similarly for SL, SO, and Sp.
Also, where we have written SP2n, some write Spn. In practice, it seems that those most interested in algebraic groups or Lie algebras use the former notation, and those interested in compact groups the latter. Other common notations are U(2n) in place of our GLn H, Sp(p,q) for our Up,q H, and O(2n) for our Un H.
Very helpful; I may not know what to write, but at least I have a fighting chance of understanding what I read! My suggestion here is
  1. Write what you know.
  2. Help the reader.
  3. In case of unfamiliarity/conflict, use the talk page.
  4. For wider input, ask here.
  5. For decisions vitally affecting many articles, propose a convention.
Be prepared for both surprises and cranks. As Richard Feynman said, "Keep an open mind, but not so open that your brain falls out." --KSmrqT 00:28, 22 February 2007 (UTC)

I see that the notations listed above do not include this:

\Pr\,

produced in TeX by \Pr .

Fropuff made a good suggestion on the talk page for the Manual of Style during the flapdoodle with the physicists over the difference between := and ≡. Unfortunately, nobody responded to his suggestion then. Do you think this discussion should move over to Wikipedia talk:Manual of Style (mathematics)? DavidCBryant 20:18, 22 February 2007 (UTC)
Yes, I think it's reasonable to discuss style there. Amir Aliev 21:30, 22 February 2007 (UTC)

Mathematics Genealogy Project and an Afd

I come here by way of a mathematician Johann Christoph Wichmannshausen, who is up for deletion and is in the Mathematics Genealogy Project. I am unfamiliar with the importance of this genealogy tree, but I notice that a number of academics provide their "genealogy" on their personal website, so my initial assumption was that people higher up in the tree should be considered notable by default. Is that reasonable? Are there some rules of thumb that can be used to assist in determining WP:N using the "Mathematics Genealogy Project" data? John Vandenberg 00:36, 22 February 2007 (UTC)

Labyrinthine processes

While reviewing some of the "new" math articles I ran across this one. Someone hit it with a "cleanup" tag in November, 2005. The tag exhorts editors to "discuss this issue on the talk page". Interestingly, the talk page is still a red link, 15 months after the tag was placed. Apparently the person who tagged the article didn't even care enough to list any specific concerns right then and there, on that talk page. Like a graffiti artist, he tagged the article and moved on.

Last week I reviewed an article consisting of 28 words (plus 107 words of encrustations from various templates affixed by editors who apparently don't think others can judge a page unless there's a neon sign on it). I put a PROD tag on that one, but one of the author's sockpuppets deleted the tag, so I had to learn about the AfD process. Now the article itself (135 words, including the barnacles) is gone, and in its place we have a (roughly) 350-word archived discussion.

I understand why some of this happens. Maybe it's just that I haven't been here long enough to get used to it yet. But it seems that some of these processes aren't really helping to make Wikipedia any better. Can some of these labyrinthine processes be straightened out, or even eliminated, somehow? For example, could the code underlying a "cleanup" tag prevent its insertion while the associated talk page is a red link? If somebody really thinks an article needs cleanup, shouldn't that editor be encouraged to identify a specific problem before waving a big red flag at everybody else? DavidCBryant 16:25, 22 February 2007 (UTC)

Sounds like everything unfolded as it should. Your AfD was the right thing to do, and everyone who participated agreed with you. If you have a page on your watchlist, and someone adds a cleanup tag with no accompanying text, just write to them and complain. This nearly always gets a response. If there is no response, put something on the article's Talk page and then remove the tag. The topic of Wikipedia:Deletion is under constant review, and a large percent of the complaints are about inappropriate deletion. Sounds like you have the opposite complaint, 'inappropriate retention'. The other article you mentioned, Prefix codes, might be a candidate for deletion. It seems disorganized; any valid material would find a better home elsewhere. EdJohnston 16:48, 22 February 2007 (UTC)
I would vote very strongly against deleting Prefix codes. It is an important topic in coding theory. I did some work on cleaning it up this morning but it still needs more. —David Eppstein 17:52, 22 February 2007 (UTC)
I agree with D. Eppstein here. "Prefix codes", otherwise known as "prefix-free codes", are important in Kolmogorov complexity as well as in coding theory. The article in question just needs to be cleaned up.
In general, I give others about a week to comment on cleanup tags that are so vague as to be useless, and remove the tags if no comments are forthcoming. Look at the recent history of Turing degree for an example. But I think eliminating the tags from WP would be a losing battle to fight. CMummert · talk 20:19, 22 February 2007 (UTC)
I'm not sure precisely which processes you thing are troublesome, but I would like to defend the use of cleanup tags. I agree that it can be frustrating to see a cleanup tag on an article when you have no idea what was meant to be cleaned up, but I'd say that the person that added the tag probably thought it was clear. As for not 'think[ing] others can judge a page unless there's a neon sign on it,' you should realize that putting the cleanup tag on a page also puts the page in a category (Category:All pages needing cleanup) so that people who are looking for something to do can pick out an article that needs help.
As for the deletion process: it can be a little annoying to have to go through a week's debate for an article that you know needs to be deleted. But, then, "it's not what you know, or don't know, but what you know that isn't so that will hurt you." Better to go through a week's worth of tiresome debate than delete an article that should be kept, I think. --Sopoforic 20:55, 22 February 2007 (UTC)
The description of that category notes "This category exists primarily as an aid to bots and other automated processes." And it is correct - Jitse's bot will notice if a math article is added to the category and note it in the daily update. There is no legion of editors poring over the actual categories to fix all articles with maintenance tags. CMummert · talk 21:02, 22 February 2007 (UTC)
Eh, well, I mostly meant people doing that sort of thing--other wikiprojects also have listings of articles needing cleanup that fall within their scope. But, some people do, I think, look at the very old categories in Category:Cleanup by month to clean up things that have been sitting for a while. I try to, anyway. --Sopoforic 21:15, 22 February 2007 (UTC)
I meant to point out there is a list maintained by Jitse's bot that lists only math articles that have been tagged. It is much more tractable than the general categories. CMummert · talk 22:07, 22 February 2007 (UTC)

Request for Comment

Talk:Indian_mathematics#Request_for_comment:_Reliable_Sources_for_Indian_Mathematics Feedback is requested for a problem on the Indian mathematics page, where two users have a disagreement about what constitutes reliable sources for claims in the article. 05:29, 23 February 2007 (UTC)

Power sum and Power Sum

There needs to be some merging with the articles Faulhaber's formula, Power sum and Power Sum. I don't know that much about mathematics to clean those up. --Montchav 11:22, 24 February 2007 (UTC)

Thanks. I made Power Sum redirect to Power sum. No information was lost since the text at Power Sum is contained at Faulhaber's formula which is linked from Power sum. Oleg Alexandrov (talk) 16:18, 24 February 2007 (UTC)

Categories for number-theoretic properties

Many articles about special classes of natural numbers are categorized in Category:Integer sequences, apparently solely because the numbers in the class form a sequence. See for example Practical number, Vampire number, or Square-free integer. I think it would be better to have a Category:Number classes with subcategories Category:Base-dependent number classes and Category:Divisor-based number classes (and, of course, appropriate cross-references between "class" and "sequence" categories). Several articles currently in Category:Number theory would also be moved to the subcategory, leaving only very important or well-known classes such as Prime number or Perfect number as direct members of Category:Number theory.

Any reasons why this would be a bad idea? Any better suggestions for category names? Category names are cumbersome to change, so it would e best to get them right from the start. –Henning Makholm 20:39, 24 February 2007 (UTC)

As far as I can see, the articles concerned are about sequences of integers - so why not just leave them in Category:Integer sequences or the sub-category Category:Base-dependent integer sequences ? Any more complex or subjective classification scheme will be poorly understood (how do you distinguish between a "sequence" and a "class" ? how you define "important or well known" ?), and you will quickly get articles appearing in the "wrong" sub-category or being put in the top level category by default. Gandalf61 14:28, 27 February 2007 (UTC)
I don't see why the distinction should be complex subjective at all. If one can determine from the definition of the class whether a given number is a member of it without needing to know anything about what the other members are, then it is only a sequence in the trivial sense of being a subset of the natural numbers. This is true for all of the three examples I gave. Why should someone who wants to learn about square-free numbers have to look in a category about sequences to find it? Expecting users to be able to think "sequence" when what they have in mid is just a property with no inherent sequential features, now that is complex... –Henning Makholm 03:20, 28 February 2007 (UTC)

Enneper-Weierstrass parameterization formula

The article Enneper-Weierstrass parameterization needs some quick cleanup that I am unable to provide. It says:

Given complex-valued functions f(z) and g(z), parameterize minimal surfaces by taking the real part of
∫ (f(x)(1 − g(x)2), i*f(x)(1 + g(x))2, 2f(x)g(x)).

The formula here needs to be re-typeset, but it also does not appear to be strictly correct: where are the differentials? What are the limits of integration?

-- Dominus 08:09, 27 February 2007 (UTC)

Here it is typeset.
 \int \left( f(x) \left( 1-g^2(x) \right), \bold{i} f(x) \left( 1+g(x) \right)^2, 2 f(x)g(x) \right)
The MathWorld version (here) takes f(z) and g(z), where r = reiφ, and writes
\begin{bmatrix}x(r,\phi) \\ y(r,\phi) \\ z(r,\phi)\end{bmatrix}
 = \Re \int{\begin{bmatrix} f (1-g^2) \\ \bold{i} f (1+g^2) \\ 2 f g\end{bmatrix} \, dz} .
It also has problems, including the use of z in different ways on the left side and the right. More reliable is
\begin{align}
 x_k(\zeta) &{}= \Re \left\{ \int_{0}^{\zeta} \phi_{k}(z) \, dz \right\} + c_k , \qquad k=1,2,3 \\
 \phi_1 &{}= f(1-g^2)/2 \\
 \phi_2 &{}= \bold{i} f(1+g^2)/2 \\
 \phi_3 &{}= fg
\end{align}
with ck constants, g(ζ) a meromorphic function on a domain D in the complex ζ-plane, f(ζ) an analytic function on D with the property that at each point ζ where g has a pole of order m then f has a zero of order 2m, and D either the unit disk or the entire plane. (Lifted from the Encyclopedic Dictionary of Mathematics, second edition, ISBN 978-0-262-59020-4.)
I claim no expertise in minimal surfaces, so someone may want to check this and fix the article. --KSmrqT 15:23, 27 February 2007 (UTC)
Many thanks. I should have thought to look at Mathworld myself. -- Dominus 15:53, 27 February 2007 (UTC)
I have changed the article; I would be grateful if someone would check my changes for errors. -- Dominus 16:28, 27 February 2007 (UTC)

Mar 2007

This is the archive file "Wikipedia talk:WikiProject Mathematics/Archive 23". It is for March 2007.

Metric spaces, et al

I'm thinking that we might want to reorganize slightly a set of articles. In particular:

Notice that we have Metric space and Metric (mathematics) both. I think that, if it isn't justified to have both an article for the (quasi)(pseudo)(hemi)(semi)(grape-flavoured)metric as well as the corresponding space, the main article ought to be for the (...)metric rather than the space, as the metric is the more 'basic' object.

It wouldn't really be much work to rewrite the articles to match this, but I'd like opinions on whether it's a good idea before I do such a thing. Also, it seems to me that regardless of whether these are to be moved as I suggested, we need to use consistent terminology throughout this set of articles. I can look into fixing this later today. --Sopoforic 11:51, 25 February 2007 (UTC)

Regularizing the terminology between these articles is a good idea, but I don't see the need to merge the articles on metrics and metric spaces. For important topics like this, there is so much to say that it is easier to split it into two articles, as long as the articles are not covering the same information. In this case, metric covers topics like equivalence of metrics, while metric space includes discussion of the topological properties of the spaces, so there is little redundancy. There is something to be said for articles that are narrow enough that they can be read in one sitting, and there are guidelines on article size that encourage medium-length over long articles.
There are lots of other examples of similar splits. We have Exponentiation/Exponential function, Arithmetical set/Arithmetical hierarchy, etc. CMummert · talk
You misunderstand me. There is currently only one article for each of those (i.e. we have Quasimetric space and not Quasimetric). I think that we should either have two articles (both Quasimetric space and Quasimetric) or that the article should be called by the metric, not by the space (i.e. Quasimetric instead of Quasimetric space). That is to say, I agree with you; do you think we should change the names of the articles? --Sopoforic 14:46, 25 February 2007 (UTC)
I see, I did misunderstand. I don't think the names matter too much, because redirects are cheap. But KSmrq pointed out below that many of the other topological space concepts are in articles with names like regular space, so the current titles for the various types of metric spaces seem to match some informal convention. CMummert · talk 20:52, 25 February 2007 (UTC)
I think both names should exist, one a redirect for the other, and that the primary name should be consistent across these articles (also e.g. injective metric space). But I don't care which convention you use to make them consistent. —David Eppstein 16:46, 25 February 2007 (UTC)
Many notions in topology named "foo" are under "foo space"; for example, "compact space" instead of "compact" (which redirects). Perhaps the idea is that to define compactness we need a space, so the idea does not stand alone. We can — and should — separate "metric" and "metric space". Partly this is because "metric" can stand alone, and partly because the technical definition of a metric used to define a metric space is only one usage. This argument does not apply to the examples that began this discussion, which do not really stand alone nor have significant other uses. --KSmrqT 18:28, 25 February 2007 (UTC)
It's not clear to me how a metric can stand alone (what is the point if it isn't defined on any set? it seems meaningless), but I am far from an expert. I only came across these articles because the topics came up in a book and I thought I'd see what we had. The motivation for my asking this is this: take a look at Pseudometric space. It is mentioned in the lede that this is a set together with a pseudometric, but the rest of the article is spent talking about the pseudometric in particular, and not the space, which made me think that it might be appropriate to rename the articles. But the feeling seems to be that they are fine as they stand, so I'll leave them be. Thanks for your input. --Sopoforic 02:12, 26 February 2007 (UTC)
As content is added to articles, their focus can often change in major ways, making any given title seem odd-fitting. If you expand these articles, say, doubling their size, then a title change may be warrented -- or maybe instead an article should be split in two. For now, the titles fit, they seem consistent, and they leave room to grow. Its an organic process. linas 03:34, 2 March 2007 (UTC)


LT code

Since Oleg included Category:Coding theory in the list of math articles a few days ago, I've been trying to review all of those new articles, to be sure they make sense. LT code doesn't make much sense to me, the way it's written. I'd appreciate an independent review by somebody here who understands algebraic coding theory.

From reading a little bit about "Luby Transforms" from other sources, it seems the best way to describe them is to think of the encoding and decoding process in terms of the "Exclusive Or" operation. Since the exclusive or of any bit string with itself is identically zero, it's pretty easy to understand how this randomized encoding strategy works. But I sure can't get that out of the existing article, no matter how hard I try.

I think I understand LT codes well enough to rewrite the article. But I'd appreciate some reassurance from someone who has previous experience with them. Thanks! DavidCBryant 01:02, 26 February 2007 (UTC)

I have no experience with these beyond having seen Luby talk about this stuff once years ago. But I think the relevant source to cite for this, among Luby's many erasure code papers, may be the FOCS 2002 one entitled LT codes. —David Eppstein 01:35, 26 February 2007 (UTC)
Thank you for the citations, David. I also found a few reasonably well-written articles that are freely available on the web, and I've finished rewriting LT code. I think it makes more sense now, but would still welcome a review by anyone who likes coding theory. Interestingly, I ran across an online article from which the original Wikipedia article was probably cribbed. At least the style of description, with bins and balls and edges and graphs, is very similar. DavidCBryant 01:25, 2 March 2007 (UTC)

Category:Important publication

I nominated Category:Important publication and all its subcategories for deletion at Wikipedia:Categories for discussion/Log/2007 February 28. Comments welcome. Oleg Alexandrov (talk) 03:21, 28 February 2007 (UTC)

There is currenlty a confusing number of top level mathematical book categories with considerable overlap. We have
Personally I think Category:Mathematical publications is a better name for the lop level cat than Category:Mathematical literature as literature generally makes me think of fiction. --Salix alba (talk) 09:56, 1 March 2007 (UTC)


Maximal independent set

I notice that Independent set is redirected to by Maximum independent set, and has 30-40 references. Since Maximal independent set is somewhat stubby and has only one reference (excluding lists), would it make sense also to merge and redirect this one? If not, I'll add enough of a definition to Independent set to refer back to it. Hv 07:11, 28 February 2007 (UTC)

I think it would make more sense to make maximal clique (currently a redirect to clique problem) and maximal independent set point to the same place, since they are complementary. I think there's enough material in both of them to make a real article rather than having to combine with other clique and independent set topics. For instance: any graph has at most 3n/3 of either type of set (Moon and Moser; see also [8]); algorithms for listing all of them in polynomial time per set (see references in [9]); planar graphs and chordal graphs both have O(n) maximal cliques though that may have many more maximal independent sets (and chordal graphs may have many more non-maximal cliques); the number of maximal independent sets on a path or cycle is counted by the Padovan sequence or Perrin sequence [10]. I don't have time to write all this in appropriate detail for an article tonight, but could probably get to it some time in the next few days if nobody else does. Though, the level of self-cites in what I've listed here may mean that someone with less of a conflict of interest would be more appropriate as an unbiased writer... —David Eppstein 07:56, 28 February 2007 (UTC)
Ok, I've added the definition and backref in independent set. If you are moved to write up the detail, I'd be happy to review it (leave me a message) from the POV of someone almost completely unversed in graph theory, but I guess you'd need another expert in the field to properly judge conflict of interest. Hv 08:24, 28 February 2007 (UTC)
I've now completed a major rewrite of the article, and redirected maximal clique to point to it. I'd appreciate any constructive criticism anyone might have, especially regarding the two self-citations. —David Eppstein 02:15, 2 March 2007 (UTC)

Overfitting, Data-snooping bias, Data dredging, Testing hypotheses suggested by the data

The following four articles:

overlap and should be merged. Statisticians call it data-snooping bias when it's accidental, data dredging if it's intentional (and data mining, before that term got taken over for something else). Testing hypotheses suggested by the data describes the same thing, and also doesn't seem to be a commonly used phrase. Overfitting is what it's called if an algorithm did it (through overparameterization) rather than a human (through pattern recognition), and indeed what the machine learning community calls it. The machine learning community have studied overfitting ad nauseum since it's the problem with tuning parameters to any supervised learning algorithm. In machine learning you always partition data into a training set and testing set, and even use cross-validation (the data dredging article calls using two sets of data "randomization"; "partitioning" would be a better descriptor).

I can see keeping overfitting separate since it's an extreme version of data-snooping bias, but the other three are definitely mergeable. Thoughts? Quarl (talk) 2007-02-28 08:49Z

I tend to agree with mergeing, but keeping overfitting seperate as it is a well used term. Statistical bias is currently a redirect to Bias (statistics) which is a short disambig. Maybe these articles would be better treated as a longer article on Statistical bias? --Salix alba (talk) 08:21, 1 March 2007 (UTC)
I think the three articles ought to be merged, probably under the "data dredging" title, with the others as redirects. I'm not so sure about lumping them in with "statistical bias", since that term is often used to refer to systematic sources of error, or bad data collection techniques, in my experience.
I think a classic example of "overfitting" is in the field of econometrics. I remember looking at some big econometric models, with maybe 350 variables input, and 600 "predicted", and maybe 940 different linear equations tying all these things together. The "technique" was to collect all the data (including "predictions") for past periods of time, and then to run this monster regression to minimize the squared error over all the data by treating the coefficients in the linear system as variables! I'd criticize this "model" as having very little predictive power, and no grounding in laws of cause and effect, but the guys who were building it said "We don't have to convince you – we just have to convince the NSF!" Now they're probably predicting next year's GDP, or the federal budget deficit, and I'm writing articles for Wikipedia.  ;^> DavidCBryant 01:07, 2 March 2007 (UTC)

Cross-project help, Vandalism Studies

Hello everyone. I was wondering if I couldn't ask for a little assistance from you fine people over here to look over our data at Wikipedia:WikiProject_Vandalism_studies/Study1. While the math isn't hard obviously, something might catch your skilled eyes that we'd miss. Also, if you have any suggestions of other things we should do with the numbers (been a while since college adv stats) we'd love to hear it on the talk page. Thanks you guys. JoeSmack Talk 17:57, 28 February 2007 (UTC)

I think that most vandalism is concentrated on high profile articles, e.g. articles about people or things in the news or articles which might be referenced in home-work assignments. I notice that Jerk, Kinetic energy, Newton's laws of motion (when it is not semi-protected), Black hole (when not semi-protected), Natural number, and Job search engine are among those which are frequently vandalized. Perhaps you need a method which emphasizes such articles. But that depends on the purpose of your survey on which I am not clear. The type of statistics needed depends on what you are trying to do.
Also, I noticed that when you computed the average time to reversion at the end, you added 14 numbers together and then divided by 30 which seems odd. JRSpriggs 10:21, 1 March 2007 (UTC)
That (14:30) looked strange to me too, JR. But it's just an artifact of the way they're doing arithmetic -- the fourteen items are subtotals, and there really are 30 instances (possibly 31? one item may have been misclassified) of vandalism in their data. Details are on this talk page. DavidCBryant 12:05, 1 March 2007 (UTC)

Monkeying around at FA

The effort to remove Infinite monkey theorem from FA has resumed at Wikipedia:Featured article review/Infinite monkey theorem, despite an admission that the original nomination is not based on an FA criterion and near-cons4ensus that the citation complaints are groundless. I think we have three courses:

  • To defeat this nomination,
  • To rewrite WP:WIAFA, as WP:WIAGA has been rewritten, or
  • To figure out what can replace FA.

This is not, of course, an exclusive or. Septentrionalis PMAnderson 04:30, 1 March 2007 (UTC)

I recommend doing some research and improving the article based on concerns from the review process. I came up with all this without setting foot in a library or even using my journal access, and this is the first time I've taken any interest in the article. Incorporating those and similar references will make the article far better and more FA-compliant at the same time. As a bonus, writing takes less energy than arguing. Melchoir 07:03, 1 March 2007 (UTC)
My personal opinion is that there is no benefit to me or WP that justifies that time it takes to nurse articles through the FA process and keep them at FA status if they are accepted. Other editors are free to do so if they find it more valuable. The FA standards are not particularly flawed, but the review process is not collegial nor enjoyable, and the standards and their interpretation are subject to change at a moment's notice.
Salix Alba commented (this page, 09:46, 5 February 2007, above) that it might be a good idea to make an A-class rating system for the math project to recognize the best articles that we have. This would fall under the third bullet above, although it would supplement rather than replace FA. I find the idea very appealing. CMummert · talk 13:13, 1 March 2007 (UTC)
Yes, I'd also like to give something like that a try. Apparently, some of the larger WikiProjects have their own procedures for assessment and peer review. See Wikipedia:WikiProject Council/Guide#Assessment and Wikipedia:WikiProject Council/Guide#Peer review (and links therein) for some ideas. I think we should just look around what others do (which I haven't done yet), find something we like, copy the procedure and try it out. One possible problem is that maths is so specialized; there are many articles for which I couldn't possibly comment on their correctness / comprehensiveness etc. -- Jitse Niesen (talk) 04:08, 2 March 2007 (UTC)

I've just stumbles across Wikipedia:WikiProject League of Copyeditors, it might be possible to enlist their help in getting keeping FA status. --Salix alba (talk) 19:43, 5 March 2007 (UTC)

I think it's unfortunate that the quality scale, for articles that will never be on the WP main page for reasons of their subject matter, stops at A. Perhaps we should lobby for an "FA-equivalent" class, meaning "just as good as an FA, but has too narrow a potential audience to put on the main page". For a great many of our articles, that would be the correct goal. While in theory the FA process is independent of subject matter, we all know that in reality they'll never put Stone–Čech compactification on the front page no matter how good it gets. (Note that I'm not saying that particular article is of that quality now, but it could be made so, if we wanted to put the effort into it.) --Trovatore 04:31, 2 March 2007 (UTC)
I don't think we have to be so pessimistic about obscure and impenetrable topics. Laplace-Runge-Lenz vector is FA, as are the articles at Category:FA-Class MCB articles. For several of those, I can't imagine that the population of Wikipedia visitors who had the ability and inclination to read the article broke 1%. And yet, at Wikipedia:Featured article candidates/Proteasome for example, no one complained that the article was too technical, and I don't see a suggestion that it shouldn't make the Main Page. Melchoir 04:56, 2 March 2007 (UTC)
Looking around Military history A class review has

Reviewers should keep the criteria for featured articles in mind when supporting or opposing a nomination. However, please note that (unlike actual featured articles) A-Class articles are not expected to fully meet all of the criteria; an objection should indicate a substantive problem with the article. In particular, objections over relatively minor issues of writing style or formatting should be avoided at this stage; a comprehensive, accurate, well-sourced, and decently-written article should qualify for A-Class status even if it could use some further copyediting.

which seems quite sensible. --Salix alba (talk) 09:17, 2 March 2007 (UTC)

Getting back to Infinite monkey theorem, I announce that my work here is done. The benefit solely from deleting the phrases "the chance is not zero, it must be one", "each individual monkey is finite", and "probably an urban myth" already justify the effort. Obviously I also expect the article to now survive FARC. Melchoir 09:01, 3 March 2007 (UTC)

How can I draw geometric diagrams?

How can I draw geometric diagrams to include in Wikipedia (with free software)? For example, I would like to be able to make diagrams like those in Penrose tiling. Thanks. JRSpriggs 09:03, 2 March 2007 (UTC)

I haven't used the program, but there's an Open Source project page for a freeware program called "Inkscape" that may do what you have in mind. They have distros for Linux, Mac, and Windows. I see that this image in the Penrose tiling article was generated with Inkscape. The image page even includes the instructions that told Inkscape how to make the drawing. DavidCBryant 12:02, 2 March 2007 (UTC)
Please visit Wikipedia talk:WikiProject Mathematics/Graphics, where you will find some suggestions and can ask for more. Geometric diagrams come in many flavors, with tilings being rather special, and aperiodic tilings still more so. In some cases, specialized programs like Tess or C.a.R will do just what you want; in other cases, programming in MetaPost or PostScript (see Casselman) is more effective; and a catch-all graphics editor like Inkscape can either add finishing touches, or perhaps be the sole tool. (Prefer SVG output, but test to be sure the half-broken librsvg renderer used by MediaWiki produces the output you expect.) The options depend on your needs, platform, taste, and budget (Mathematica is powerful but pricey). --KSmrqT 21:40, 3 March 2007 (UTC)

B+ rating and Wikipedia 1.0

One of Oleg Alexandrov's bots automatically updates the table Wikipedia:Version 1.0 Editorial Team/Mathematics articles by quality statistics. Here is a static version from when this message was posted:

Mathematics
articles
Importance
Top High Mid Low Total
Quality
Featured article FA 5 3 2 2 12
A-Class article A 9 6 1 16
GA 2 7 7 16
B 50 47 31 13 141
Start 22 30 30 29 111
Stub 5 16 30 51
Unassessed
Total 88 98 87 74 347

There is no line for B+ articles here, because WP 1.0 does not include B+ as one of their ratings - it is a project-specific rating. There are currently 38 math articles rated B+, which is about 10% of all rated articles. The math rating template already puts all B+ articles into both the B+ and B-class categories, so B+ articles are included in the B line of the table. But this duplication does not seem to be well known.

The upshot of this is that when an article is rated B+, it is not easy to find that out except by browsing categories. There are several options here:

  • Get rid of the B+ rating, and just use the B and A ratings.
  • Make a separate bot to generate a different table that does include B+ articles.
  • Ignore the problem

I am posting this message here to gather opinions about what to do. CMummert · talk 16:22, 1 March 2007 (UTC)

If we are going to rejigger this system, we should remove FA and GA classes from it; the fewer articles approved by those people we have the better. I defer to the graders whether they make a real distinction between B and B+.Septentrionalis PMAnderson 17:24, 1 March 2007 (UTC)
The standards for FA and the stanards for GA are different and run by different groups, and an article can achieve FA status technically even if it has not gotten GA status. GA is where all the problems are, not FA. JoshuaZ 08:02, 2 March 2007 (UTC)

Here is an example of the type of thing that can be done with a project-specific table. Unlike WP 1.0 bot, this program sorts out the B+ articles and uses backlinks to sort the articles by field. Of course there is room for improvement. CMummert · talk 20:21, 1 March 2007 (UTC)

{{Wikipedia:WikiProject Mathematics/Table}}

Looks cool. But you need to put it on a page different than Wikipedia:Version 1.0 Editorial Team/Mathematics articles by quality statistics as that one will be overwritten by WP 1.0 bot. How did you generate the above table? You're very welcome of course to use my bot's code if you find it useful. Oleg Alexandrov (talk) 05:13, 2 March 2007 (UTC)
Yes, it would be inside the math wikiproject namespace. The idea is to be completely independent of WP 1.0. I'll put a comment about the script on your talk page. CMummert · talk 05:46, 2 March 2007 (UTC)
Oh, that's a very nice table. I like it much better. One question, though. Is there a list of e.g. stub-class high-importance articles, or start-class algebra articles, or such? I think there's a tool... catscan or something... that will let me do intersections, but it'd be nice if there were already a category. --Sopoforic 06:36, 2 March 2007 (UTC)
I can certainly generate such a list using the same script. There are tables right now that are maintained by hand, and I don't want to figure out how to parse those. Also, my script does not download any articles or talk pages, so I can't fill in "comments" into the tables. But I can make a simple list. I also have to diagnose some bug in my setup. CMummert · talk 14:30, 2 March 2007 (UTC)
I see that Wikipedia:Version_1.0_Editorial_Team/Mathematics_articles_by_quality is sorted by class and then importance, which takes care of the first part. Is there anything for the second part? --Sopoforic 06:38, 2 March 2007 (UTC)
V nice. Minor point in the second table you will need an unassessed field row. If you working on a bot it might be cool to automatically generate the the field specific tables such as [[11]].
If we are redoing thing, it might also be worth considering a B- rating. While assessing article I've found that there is a big gap between Start and B. Not as useful as the B+ rating but worth a look. The reason B+ articles are currently put in both the B and B+ cats was primarily so WP 1.0 bot could do it thing and also to allow some measure of consistancy with other projects and the global table of all assessed articles. --Salix alba (talk) 07:56, 2 March 2007 (UTC)
For the time being, B+ aticles are still in the B class category; my script takes account of the duplication. I agree that, for the WP 1.0 tables, we might as well lump the B+ articles in with the B articles.
The unassessed field row would be there, except that I took care of all the unassessed articles yesterday. It will appear if there are any unassessed articles. The "none" column should also be suppressed when not needed (Oleg's script does so), but that is slightly less trivial so I didn't do it for the original proof of concept. CMummert · talk 14:30, 2 March 2007 (UTC)

The real question: which ratings are useful?

The central question here is: What ratings are useful for the project? Let's assume that that ratings themselves are useful, so the question is just how many different grades we need and what they mean. Right now, there are 5 that we can assign, which I understand as follows:

  • Stub: trivial coverage, half a page or less when printed
  • Start: not a stub, but minimal coverage. Could be called C-class.
  • B: Obvious holes in coverage, nonstandard POV, or cryptic writing. But some areas are covered well.
  • B+: Roughly equivalent to GA status. Experts will recognize holes in coverage.
  • A: Excellent article. Roughly equivalent to FA status.

I find it hard to distinguish between Start class and B class. What criteria could be used to distinguish between Start, B and a new B- class? Wouldn't it be easier to just add some guidance like "When in doubt between B class and Start class, go with Start class"? CMummert · talk 14:30, 2 March 2007 (UTC)

B articles are longer than start, but still missing stuff or written from a narrow/uninformed POV. linas 00:06, 3 March 2007 (UTC)
Start-class only have one decent section, or only a couple of lines on the aspects of the topic. The quality of an article is acontinuous thing, as we're assigning discrete quantities to it, so there will always be borderline cases. Tompw (talk) 22:51, 6 March 2007 (UTC)

Prime factorization of 1?

I made the following change to the Integer factorization:

By the fundamental theorem of arithmetic, every positive integer greater than one has a unique prime factorization. One does not have a prime factorization because one is not defined as a prime number and therefore can not be written as the product of any prime numbers. [12]

An IP editor reverted this leaving this comment on the edit summary: The empty product is 1 (See explaination in the article on the fundamental theorem of arithmetic)[13]

I don't understand how this makes my contribution incorrect. I understand that 1 is the product of no numbers (like how anything to the zero power is 1). But the question of prime factorization is whether a number can be written as the product of prime numbers, so how does that fact say anything about whether 1 can be represented in such a way?--Jersey Devil 17:52, 2 March 2007 (UTC)

The empty product is a prime factorisation, because all the factors in the empty product are primes (trivially). In other words, 1 can be written as the product of 0 prime numbers. Perhaps slightly confusing at first, but quite reasonable, and it makes everything neater. JPD (talk) 18:06, 2 March 2007 (UTC)
Yoink. Melchoir 18:17, 2 March 2007 (UTC)
There's no point in arguing with the empty-product crowd, Jersey Devil. You can point out to them all day long that the sentence "1 can be written as the product of 0 prime numbers" means the same thing as "1 cannot be written as the product of any prime numbers". And they won't listen, or they'll tell you you're wrong. When you ask them to write down 0 numbers and they don't do it, and then claim that they've already done it, and there's "nothing" to it, you can begin to grasp the difference between that kind of formalistic logic and the kind of thinking you and I do. DavidCBryant 19:03, 2 March 2007 (UTC)
No it doesn't. 0 is not the empty set. Septentrionalis PMAnderson 20:16, 2 March 2007 (UTC)
Does "0 can be written as the sum of 0 integers" mean the same thing as "0 cannot be written as the sum of any integers"? -- Dominus 21:01, 2 March 2007 (UTC)
No, it doesn't mean the same. The first statement is true (because the empty sum is defined as 0). The second one is false. Counter example: 3 + (-3) = 0. Ocolon 21:07, 2 March 2007 (UTC)

If you think the prime factorization of 1 is confusing, just try thinking about the prime factorization of 0. It's divisible by every prime power! —David Eppstein 19:06, 2 March 2007 (UTC)

This discussion highlights a phenomenon we've seen many times before. (Until recently, I was involved in a similar discussion about 0^0 at the page Exponentiation.) The point was made there, and I'll make it here, that we here at Wikipedia need not argue about the logic of any given convention. We report what is out there in the literature. On the Exponentiation page, we have a section on 0^0 that describes two different conventions in the literature without judging either as being correct or incorrect. (We mathematicians have a hard time admitting that sometimes two different statements can both be correct, Continuum hypothesis aside, since they are matters of convention.) Why not the same thing here? If there are books that say that 1 can be written as the product of primes, fine. Just report the source of the statement. Alongside it, we absolutely have to report that most books restrict any such statement to integers n > 1, whether they "need to" or not. VectorPosse 23:51, 2 March 2007 (UTC)

Off topic here -- the matters you are discussing are matters of convention; the continuum hypothesis is not. --Trovatore 00:05, 3 March 2007 (UTC)
Fair enough.  :) VectorPosse 00:52, 3 March 2007 (UTC)

For a source, see Hardy and Wright: Number Theory. As far as I know, there is no source which denies that 1 is an empty prime product. Editors can write around this convention if they like, but other editors are likely to follow it; it is simplest. Septentrionalis PMAnderson 03:49, 3 March 2007 (UTC)

Strayer's Elementary Number Theory states the Fundamental Theorem of Arithmetic only for integers strictly greater than 1. Then there is an exercise explaining why the statement of the theorem would be (should be?) untrue for 1. So there's the opposing sources I mentioned above. By the way, I'm not sure a book has to deny explicitly that 1 is an empty prime to be a source for the convention that we should restrict attention to integers greater than 1. I think it's also a matter of debate which convention is simpler. (Simpler in terms of the necessary hypotheses, or simpler for the lay reader?) But maybe this discussion has reached the point at which it should be taken to the talk page. VectorPosse 06:10, 3 March 2007 (UTC)

I've now posted my thoughts on the matter at Talk:Fundamental theorem of arithmetic and Talk:Integer factorization. Feel free to chime in at either of those places. VectorPosse 06:37, 3 March 2007 (UTC)
Every positive integer less than 11 can be written as 2k·3m·5n·7p for some non-negative integers k, m, n, and p. In particular, 1 = 20·30·50·70. Get the picture? JRSpriggs 12:42, 3 March 2007 (UTC)
Sorry, but I'm not clear who is meant to "get the picture". Are you talking to me or someone else in the thread? For the record, I agree you and with the aforementioned "empty product crowd". I'm talking about reporting multiple conventions, not arguing the logic. My entry on the talk pages listed above should clarify. (A discussion seems to be forming at Talk:Fundamental theorem of arithmetic.) VectorPosse 13:22, 3 March 2007 (UTC)
To VectorPosse: I should have made it clear that I was addressing Jersey Devil and anyone else who might agree with him.
To Jersey Devil: If instead of just thinking of a product of primes, one thinks in terms of a product of powers of all (distinct) primes, then it should be clear that 1 is in no way exceptional. JRSpriggs 11:55, 4 March 2007 (UTC)
I think I get the picture: every integer n is even, since n=2^0 n and so, 2 is a prime factor of n, ergo, n is even. So, for example, 3 is the product of zero twos, and thus, 3 is even. linas 17:03, 5 March 2007 (UTC)
There is much more of a difference between saying something is a product of primes and saying something has a particular prime factor than there is between the empty product and other prime factorisations, so this smart comment really only misses the point. I can understand people objecting to the idea of empty product conventions, but the original question accepted that, and asked how that affected prime factorisations. The fundamental theorem is more importantly about uniqueness of the factorisation achieved than anything else - it is silly to exclude the case where there is no factorisation needed. The more general "product of a unit and (powers of) primes" (for any UFD) covers this without the difficulties of empty product conventions. JPD (talk) 17:56, 5 March 2007 (UTC)

Creation of a Mathematical Formulas Page

I believe it would be a good idea to add a page with formulas used in mathematics. They could be grouped into categories of different areas of math with explanations and examples of the equation. This would be of great help for many students.--Trd89 23:16, 2 March 2007 (UTC)

Go for it. It shouldn't be hard to list all three of them, lets see, E=mc2, A=pi r2 and I keep forgetting the third one. linas 00:27, 3 March 2007 (UTC)
We do have pages (e.g. the articles at Lists of integrals) like this, which are of debatable value. However, wikipedia probably isn't the place to create a list of formulae for students. Wikibooks, however, might welcome such a page. The problem with creating them here is that such lists generally won't have much encyclopedic value; they may serve as study aids or quick-reference guides, but they probably aren't appropriate for encyclopedia articles. Also, it would be very difficult to come up with appropriate criteria for inclusion. I could probably produce on the order of a hundred very commonly used formulae without half trying, and I know of whole books consisting of nothing but identities which could conceivably be included in such a list. --Sopoforic 00:49, 3 March 2007 (UTC)

This site would be used for formulas and not identities. for example what (a+b)3 factors down to--Trd89 03:04, 3 March 2007 (UTC)

Some more focus would help. A list of formulas is too broad and the content would be overwhelming. See List of formulae involving π for an example of a more specific page of this type, which has nevertheless undergone attempted deletions because some editors feel such lists are not appropriately encyclopedic. —David Eppstein 03:09, 3 March 2007 (UTC)
Would this be better suited to wikibooks? Septentrionalis PMAnderson 03:50, 3 March 2007 (UTC)

Essentially, you are asking us to take virtually all the articles on mathematics (since they all contain formulas) and strip out the words that give context and meaning to the formulas, then combine the resulting mess into one MONSTER article which be would thousands of times longer than the limit for an article. This is the dumbest idea yet. JRSpriggs 12:34, 3 March 2007 (UTC)

Please be civil. Ocolon 18:01, 3 March 2007 (UTC)
Has Political Correctness gone so far we cannot label a dumb idea as such? We all have dumb ideas, some blatantly so, others with hidden defects; it is vital that we recognized these. Claiming an idea is dumb is not the same as calling a person dumb (or worse). Which is more polite, to be told that I have spinach in my teeth, or to walk around all day with everyone noticing and pretending to ignore it? And which is better for the common good, to let a dumb idea go forward, or to kill it quickly?
The main reason I rarely call ideas dumb is cowardice; if I should be proved wrong, if the "dumb" idea leads to worthwhile results (like Wikipedia!), then the one who looks dumb is me. Since my Wikipedia credibility depends on never being wrong and always being Politically Correct, I can't afford to risk it. ;-)
Instead of chastising the language of JRSpriggs, we should applaud the courage and clarity. We are far better off removing the stigma from making mistakes than taking politeness to the point that we won't mention them. In the words of Thomas J. Watson, “The fastest way to succeed is to double your failure rate.” It is not to pretend that failures are successes! In that spirit, I would encourage JRSpriggs to verbally support Trd89's desire to improve Wikipedia while lambasting the present proposal as hopelessly naive and unworkable. Because maybe there's a germ of a good idea there, one never knows; or maybe the next, unrelated, idea will be terrific. And even if Trd89 churns out nothing but bad ideas, we would like to encourage those who might have good ones. --KSmrqT 23:04, 3 March 2007 (UTC)
Okay. Ocolon 09:26, 4 March 2007 (UTC)

I think the idea to add formula only-pages would cause unnecessary redundancy. The formulae are already where they belong to in an encyclopedia — in those articles that handle their topic. Ocolon 18:01, 3 March 2007 (UTC)

Thinking in terms of our users, mathematical formula is probably a common search term, as a jumping off point to Lists of integrals, List of formulae involving π, List of trigonometric identities, would probably help what they are looking for quickly. --Salix alba (talk) 00:00, 4 March 2007 (UTC)
We might have a jumping-off page that links to those existing lists. However, I foresee endless trouble with such a page if some well-meaning user starts adding formulas to the page itself, and others find themselves inspired to attempt to make an exhaustive list of it (there ought to be, somewhere in project space, an essay about the danger of starting lists with unclear inclusion criteria, because someone will always attempt to make them exhaustive). I don't think it would work without a big bold self-reference saying that most formulas in Wikipedia are found only in articles about their subject and not in any list, and that this is intentional and desired. –Henning Makholm 00:08, 4 March 2007 (UTC)

See also Wikipedia:Articles for deletion/List of well known mathematical formulas. Quarl (talk) 2007-03-04 09:57Z

Formulae articles suggestion

I have made the request elsewhere, but am copying a version here:

When a formula is described on Wikipedia, a one or two sentence non-mathematical introduction is included - aimed at persons who are outside their field with the given topic.

"It was developed by [abc] in [date]. This formula is used in the area of [xyz] and its purpose is to do [def]."

(Can someone archive part of this talkpage - getting slightly long).

Jackiespeel 18:54, 5 March 2007 (UTC)

Good writing, which we aspire to, does include giving English descriptions of formulas. There are a lot of articles that need to be improved, so this goal is not yet met in practice. If you find one that is particularly confusing, you may add the {{confusing}} template, but doing so does not guarantee that anyone will quickly appear to edit the article. This talk page is archived automatically, as explained at the top of the page. CMummert · talk 00:11, 6 March 2007 (UTC)


Graphs of theorem dependencies, and tables of examples

How feasible would it be to create either a graph of theorems and axioms or a crossindexed table of examples, like the one at the back of "Counterexamples in Topology"? I know it would be quite an undertaking, but either would be pretty great. Prc314 23:40, 6 March 2007 (UTC)

To do page

I wanted to help, and looked at the Wikipedia:Pages_needing_attention/Mathematics page. Is it possible to sort these items according to topic, i.e. algebra analysis etc. This would help to guide people (like me) with only special knowledge to the articles needing help much quicker. Thanks. Jakob.scholbach 02:06, 7 March 2007 (UTC)

It's not so easy. We need to devise a scheme to decide whether an article is algebra, analysis, topology, etc., and then program it. It's probably possible, but I'm not convinced it's worth the effort. After all, you can just scan the list and pick out the articles in your specialization. Granted, it takes more time and you'll probably miss some, but after you have poked around for a couple of weeks, you'll soon have a list of things that need to be done and (at least in my experience) the list always grows faster than that you can resolve the issues. -- Jitse Niesen (talk) 23:30, 8 March 2007 (UTC)
There is some progress on this front with the {{maths rating}} template. On that there is a field parameter which can be used to indicate the broad field of an article. Quite a rough tool and its not always clear which field to pick, and theres only 350 or so articles which have been graded to date. Anyway you may find Wikipedia:WikiProject Mathematics/Wikipedia 1.0/Analysis and other pages of some help. BTW its probably time we actually did something with the field parameter, say putting those articles in a category or something cleaver with a bot. --Salix alba (talk) 00:11, 9 March 2007 (UTC)
I can say from experience that having a category would be very convenient for automatically determining which articles are assigned to each field. The current method I use to create this table is not theoretically perfect. CMummert · talk 00:55, 9 March 2007 (UTC)

Structure theorem for finitely generated modules over a principal ideal domain

Could someone review Structure theorem for finitely generated modules over a principal ideal domain? It has been recently created and caught by our bot as copyvio, but apparently it is a false positive (and would like a member of this project to review it and decide if it is notable enough for Wikipedia (as the only reference is a PDF). If it is suitable, please tag the article appropriately. If it is not, please prod, afd or inform me so that I can proceed. Thanks in advance! -- ReyBrujo 03:08, 7 March 2007 (UTC)

Took a quick look, so i can't vouch 100% for its contents. But this looks like the classic decomposition theorem for modules. I would guess it's already in some other article though. --C S (Talk) 03:19, 7 March 2007 (UTC)
I think in that case it would indeed at least deserve a renaming (or if it is somewhere else being either deleted or transformed into a redirection). I leave it to you since I suck at maths ;) -- lucasbfr talk 17:52, 7 March 2007 (UTC)
I'm not sure why it would be renamed. Despite the long name, that is what it's called. And while the article could use a little work, it's certainly notable and important, and therefore deserves an article. VectorPosse 19:03, 7 March 2007 (UTC)
Ok, I will remove it from the copyvio watchlist. Thanks for the help! -- ReyBrujo 20:56, 7 March 2007 (UTC)

Jimbo Wales' proposal for credential verification

Recently there has been a small media storm (e.g. [14]) over the revelation that Essjay, a bureaucrat and Wikia community manager, has misrepresented himself, in particular his credentials as a professor of theology at a university. Jimbo Wales initially stated that he regarded this as only utilizing a pseudonym; after learning more details, Jimbo came to the conclusion that Essjay had used his false credentials to bolster his arguments in editorial discussions and so asked him to resign his positions of trust (which he did). Essjay has subsequently left Wikipedia[15].

Jimbo has on his talk page proposed an optional procedure similar to Amazon's "real name" mechanism. Editors wishing to verify their credentials may do so. Jimbo envisions a related policy whereby someone stating unverified credentials would somehow be discouraged for doing so.

Now what does have to do with us? And why am I posting these comments? Well, I've been reading the comments on Jimbo's talk page with regards to this proposal. It struck me that there are several issues that our community is quite unique and perhaps suggestive of a model of how the ideal verification system should work.

Let me basically break up these issues into two groups: 1) trust-based editing, 2) dealing with cranks.

1) There have been arguments against Jimbo's proposal because people understand this (perhaps wrongly) to be about using credentials to bolster one's editing, e.g. "Your edit should be reverted because you don't have a Ph.D. and I do!" I'll try and abstain as much as possible from getting into the issues of whether this is a correct understanding or not of the ramifications of the proposal; my desire is only to explain why our WikiProject experience is relevant to the proposal. In our WikiProject we have a number of credentialed (or near-credentialed :-) ) experts. Somehow we manage to give these people the necessary respect without kow-towing to their authority, and conversely these expert editors manage to not act like such, but utilize policy to justify their edits and decisions.

One explanation for this is that such experts manage to show their expertise in their edits and are generally good at learning the relevant policies in a timely fashion. The expertise is viewed favorably by other editors, who often make the transition to Wikipedia easier for these editors. Speaking for myself, I judge an editor based on his/her edits, but find that credentials often help in understanding someone's background and expertise.

Another explanation is that we are sufficiently insulated from the rest of the community (including a number of trolls and vandals) that we don't have the same issues. This explanation is partly bolstered by the increasingly frequent disconnect between mathematics editors and long-standing non-mathematical editors in discussions on citations, articles reviews, etc. On the other hand, my experience with the second set of issues suggests that the occasional problematic editors we do deal with often require as much effort or even more effort than non-math editors deal with.

2) A number of project members have experience (either directly or indirectly) of cranks, particularly on Wikipedia. A common argument going on right now on Jimbo's talk page is whether policy by itself can handle cranks adequately. Some suggest that the use of credentials can be useful for say, mediators, in determining crankiness. It seems to me that some project members have dealt with such cranks for often very extended amounts of times (with some ongoing). This suggests that it is not as easy for experts to deal with cranks as some have asserted in response to Jimbo's proposal. In my experience, the hardest cranks to handle are the ones that offer myriad citations, sometimes to hard to obtain documents, that can take days or weeks to investigate (by going to the university library, waiting for interlibrary loan, or whatever) and refute.

I think it would be helpful for people to go to Jimbo's talk page and explain their experience, particularly with respect to these two kinds of issues. Somehow we've struck a right balance between relying on credentials but also on a person's body of editing. I think this is something the rest of Wikipedia can learn from, or at least to consider why it may not be viable for all of Wikipedia. --C S (Talk) 21:04, 6 March 2007 (UTC)

Yeah; one of the more troublsome cranks was highly credentialled - the problem was that he (Carl Hewitt) was an overly agressive self-promoter with no self-control. linas 01:11, 8 March 2007 (UTC)
The Carl Hewitt problem was deeper still. Earlier in his career he made substantial, valuable contributions to computer science at MIT. The MIT AI Lab, and MIT generally, can nurture individuals who are bright and unusual. One well-known example is Richard Stallman, who founded the Free Software Foundation, and who arguably marches to a different drummer than most. For MIT at large, a famous example is Noam Chomsky, whose major contributions to linguistics are accompanied by controversial and outspoken political views. But Carl drifted so far out of the mainstream that his own field was unwilling to follow him. He is convinced he is correct, and often asserts priority, both vigorously. Perhaps history will prove him right and everyone else wrong, but at the moment that seems unlikely. Carl is not a common crank, despite a similar disruptive pattern of behavior.
Research is often portrayed idealistically as a pure search for knowledge, innovation, and improvement. With experience, one sees that the search is not completely pure. Human beings have egos and ambitions and insecurities and complex social dynamics, as well as a broad spectrum of intellectual strengths and weaknesses. Whenever we talk, write, or listen, we are dealing with a person, not an abstract machine, and it is helpful to keep that in mind as we evolve our systems and procedures. The (impossible) goal is to support the remarkable good each person may be able to contribute, while protecting ourselves from the not-so-good.
One theory of sociology says that every group draws a boundary around itself, separating acceptable from unacceptable, with ways to (attempt to) enforce the distinction. Similar ideas appear in cultural anthropology. No doubt Wikipedia's ways will provide fertile raw material for a number of doctoral dissertations in these fields. Meanwhile, we must muddle on.
My only suggestion is vague: to combine common sense with compassion, to regard the facts dispassionately while never forgetting the humanity behind them.
We may eventually find that the mathematics community here appears to work well only because it has not been challenged to the same extent as other parts of Wikipedia. Some folks also make that claim about the remarkable scarcity of worms and viruses for the Mac OS compared to MS Windows — and have been making the same claim for decades. My suspicion in both cases is that the communities are at least as important as the systems. --KSmrqT 06:10, 8 March 2007 (UTC)
I don't know if this adds anything, but when a new user, User:LBehounek, arrived and started editing stuff on T-norms, a quick google told me that he was a graduate student or something in the Czech Republic. After noticing a couple more edits were good, I found I didn't have to watch too closely, as he liked to make many small edits at once. Its a sort of "trust, but verify" thing. What made it much easier, though, was that the user used part of his name in the username. I think that this is more common in some communities (math, science?) than in the general population. This openness makes a big difference. Smmurphy(Talk) 06:41, 8 March 2007 (UTC)
The 2 problems with EssJay were (1) that the credentials he claimed to have on Wikipedia got taken as fact and falsely-asserted off Wikipedia and (2) that he asserted credentials to try to gain the upper hand in a content dispute. I don't care how many Ph.D.s someone has; "trust me" is not acceptable verification for Wikipedia articles. Everyone has to cite a reliable source for content asserted in an edit. And let's say that a non-expert makes an edit that they, in good faith, think makes the article better, but unfortunately introduces a subtle error. Then the response is that the person who catches the error fixes it (hopefully in a way that still addresses the first editor's concern) and maybe leaves a polite note on the editor's talk page encouraging them to keep editing but to discuss potential changes on the article talk page first. That's the system now, and I think that it works fine. If the credential verification procedure happens, people are going to be afraid to edit sections created by someone with a higher credential, and I don't want that to happen. Do we have to create a rule or procedure every time some (insert not-nice word of choice here) finds a way to abuse the Wikipedia system?
Anyway, the problem has now been resolved, and now we're all aware to not take someone's asserted credentials at face value. That whole "fool me once..." etc. thing. I'm going to go post this at Jimbo's talk page now. Thanks for bringing it to our attention. --JaimeLesMaths (talk!edits) 07:11, 8 March 2007 (UTC)
Trust. When wikipedia works is it is when there is trust among the editors, trust that editors put NPOV above personal objectives, trust that people do not make false claims about their credentials. When wikipedia breaks is when the trust fails. Either when the user breaks the trust or when the administration fails to trust the users. It would be a sad day when the trust is replaced legislation. --Salix alba (talk) 09:13, 8 March 2007 (UTC)


cleanup of "independent variable" and "dependent variable"

Both of these pages begin by suggesting that the design-of-experiments usage is the principal topic of the article. That is ridiculous. Then they treat the usage that everyone learns in high school, and independent variable gives a stupid definition by non-essentials: the variable plotted on the x-axis.

Also, there should be a conspicuous link to statistical independence, since that is where the topic of independent random variables is treated.

I'm leaning toward (1) redirecting "dependent variable" to "independent variable" and making the latter to into a disambiguation page.

  • An independent variable is
    • in mathematics, an argument (input) to a function, the dependent variable being the value (output);
    • in design of experiments and various other areas of statistics, a variable controlled by the experimenter or at least one whose causal consequences one wants to consider;
  • possibly some computer-science meanings too?

Another problem is how to direct the many links to these pages. I suspect some of them are already pointing to an inappropriate place.

Michael Hardy 22:54, 9 March 2007 (UTC)

I think the notion "dependent" in dependent versus independent variable in the design of experiments and statistical hypothesis testing is not related to the notion of statistical independence of random variables. It is an unfortunate coincidence that the same word is used with unrelated meanings in somewhat related contexts.  --LambiamTalk 17:25, 10 March 2007 (UTC)

It's not compmletely unrelated, but it's certainly quite a different thing. Hence the need for a disambiguation page. Michael Hardy 02:54, 11 March 2007 (UTC)

Isn't it sufficient to put dablinks at the top of the relevant articles? By the way, I followed a few what-links-here links backwards, and about half of those were completely misdirected, involving a meaning of "(in)dependent" independent of that of any the articles under discussion here.  --LambiamTalk 05:34, 11 March 2007 (UTC)

OK, I've reorganized it, and NOT as a disambiguation page. I moved "independent variable" to dependent and independent variables and redirected "dependent variable" to the latter, after pasting some material from "dependent variable" into "dependent and independent variables". I put in a dablink to statistical independence, where the concept of independent random variables is treated. Michael Hardy 23:49, 11 March 2007 (UTC)

References

In lots of math articles in the Wikipedia, theorems etc. are stated without proper reference. (E.g. the properties of Étale cohomology). In research articles, ideally all statements (except those the author believes to be known by everybody) are cited very concretely, i.e. [..., Theorem ...] etc. I would propose this for Wikipedia articles, too. What do you think? Jakob.scholbach 05:32, 8 March 2007 (UTC)

I guess it couldn't hurt to include theorem numbers in footnotes if the latter are already present. Melchoir 05:56, 8 March 2007 (UTC)
Étale cohomology, like all articles, should at least list some good references at the end so that readers know where to go to find an authoratative treatment. Please feel free to add some if you are familiar with the area. As with many topics, an untrained reader is likely to be unable to easily comprehend these references, even though the article itself may be understandable.
A lot of discussion has gone into the purpose and utility of inline citation in math articles. There are guidelines that document the project consensus on the issue. In practice, the consensus in the math project favors correct and useful articles with few citations over short, less useful articles that give a citation for every sentence. In practice, if you ask politely for a citation of a particular result on the talk page, somebody will usually be able to give you one (or, better, explain why the theorem is true). CMummert · talk 12:36, 8 March 2007 (UTC)
The following is a vigorous endorsement of what CMummert just said. (It is also long-winded; mea culpa.)
Something I have not seen discussed is effort. When I write on a topic I know, my first focus is on the writing. Who is my audience, what must be said, how best to say it, and would a figure help? Often I do a little research for inspiration, completeness, and fact checks. (That includes jogging my memory with things I wrote in the past!) I also like to include at least a few good references, for various reasons; WP:V, Wikipedia's peculiar approach to reliability, is not one of them. Finding and documenting those references can be a great deal of additional work beyond writing the article.
Editors who do not know a topic, who write by copying out of a text with little understanding and no knowledge of context in the field, presumably start with a reference and work forward. For some topics, this describes me, too, though perhaps having more "mathematical maturity" helps always.
Wikipedia grows in both ways. I worry that those who can only copy will force their limitations on the experts. I far prefer a solid well-written article with no references to a citation-studded article that is poorly done.
∗ Some will be shocked that I claim an article can be valuable even with a theorem that is not meticulously correct. Welcome to reality. The peer-reviewed literature contains mistakes. We don't like it, we try to avoid it, but it happens and we can usually recognize the errors and find a correction. (Though I would not like to have been in Andrew Wiles shoes before he found the fix to his famous mistake!) A well-written article serves as a kind of error-correcting redundancy; for, the better we understand what was meant, the easier it is to spot and fix slip-ups. Moreover, an appealing article will attract more readers, and more eyes will spot more problems.
References do not make a good article, they are simply one more positive factor, like figures or examples or meticulously correct theorems. In fact, my approach to references is very much like that of creating a good figure or finding a good example; what will best benefit the reader?
As to the proposal of the poster, consider two scenarios. In one, a copier found a definition or theorem somewhere, transcribed it (correctly, we hope), and included a reference. In the other, an expert patiently explained as one might teach a class, in a manner unlikely to find its way into a formal publication. Do not imagine that upon consulting the references that the clouds will part and illumination will shine through. Do not underestimate the value of an expert explanation.
Mathematics has a considerable reservoir of underground literature, such as lecture notes and unpublished manuscripts, as well as many face-to-face conversations recorded nowhere. After all, when only a handful of people in the world are investigating a specialty, these informal methods of communication are more cost-effective. Even when formal publications do exist, finding a copy can be next to impossible.
Fortunately, mathematics has one significant advantage over, say, paleontology or comparative literature. We don't necessarily need a reference to verify or refute a claim.
What we do need is clear, compelling writing, so we can understand the topic and take an interest. If sometimes that means the references are not all we might hope for, so be it; they may never be, despite our best efforts. --KSmrqT 22:58, 8 March 2007 (UTC)
CMummert, KSmrq, the choice between attributed, inadequate explanations and thorough explanations off the top of the editor's head is a false dilemma and, I think, dangerously misleading. One can build prose that is both thoroughly explained and thoroughly sourced; the catch is that it requires more thinking and more research than one will ultimately communicate or cite. We are beginning to build examples that show that the extra effort is worth it.
On the other hand, if you think you can most efficiently contribute to Wikipedia by personally adopting a different methodology, that's fine; someone else will build upon your work. But please don't discourage other editors from being the best they can be. Melchoir 23:25, 8 March 2007 (UTC)
Sigh. Lest silence be taken to connote assent: your representation, Melchoir, of what I wrote above is a gross distortion. (I do not presume to speak for CMummert.) And I might sadly note: yet again. CMummert and I support the guidelines for appropriate references; you do not. Let's leave it at that. --KSmrqT 07:30, 9 March 2007 (UTC)
You ask us to "consider two scenarios"; surely you will admit that is an incomplete treatment of the issue?
No, let's not leave it at that. I support the application of those guidelines of which I am aware, including WP:SCG. You, on the other hand, supported[16] just last week maintaining the Featured status of an article with zero secondary citations[17] that made concrete mathematical claims in direct contradiction to the published literature. So much for not necessarily needing references. Melchoir 07:48, 9 March 2007 (UTC)
Two more paragraphs, three more distortions; yet another waste of our time. --KSmrqT 09:25, 9 March 2007 (UTC)
Let me guess; in your defense, you didn't actually read through Infinite monkey theorem before casting your drive-by vote-on-principle. Therefore you can't be held responsible for the details of that situation? Melchoir 09:50, 9 March 2007 (UTC)
Woah guys, can we be WP:COOL, this discussion is fast aproaching that of two pissed off monkeys. --Salix alba (talk) 11:44, 9 March 2007 (UTC)
I was perfectly happy to let it go when KSmrq called the FAR "madness"; it was just one edit to a fairly obscure page. But I was definitely pissed off by what I saw in that article. There was pettiness, speculation, and plain old inaccuracy. This from a Featured Article that had been written and maintained by some of our best editors. The bit about the zero-one law, for example, is inspired by Michael Hardy's original version of the article, which made a rather conservative statement about historical usage. Eventually, in late 2004 — I don't have the diff handy — it was explained in a badly inaccurate way by an editor whose contributions include almost no other mathematics articles, and who apparently lacked the habit of precision. The new explanation survived for more than two years, during which the article was Featured and widely read. It wasn't attributed to a reliable source, but then again, neither was anything else, so it didn't stand out. Even when its veracity was challenged on the talk page, there was no source to consult, and the error was not caught or corrected. It took someone (me) to systematically go through the article, cite what's possible, and throw out the rest in order to get rid of the problem. Every other editorial mechanism failed at this most basic of purposes: not being wrong.
I'll cool down if KSmrq acknowledges that in practice, sometimes you really do have to demand a source for something, and you can't be satisfied just because an expert thinks it's self-evident. We can go from there. Melchoir 12:29, 9 March 2007 (UTC)
Actually, I had no plans to respond further. I felt obliged to note that Melchoir had distorted my statements, but one might as well get upset with the sun rising. If he feels the voices trouble him less when he wears the foil hat, there is not much hope of convincing him to remove it. (Here's a classic example.) Having wasted far too much time in the past trying to reason with him, I do not wish to travel that road again, nor to drag others through such an ordeal. --KSmrqT 00:05, 10 March 2007 (UTC)
I admit that I handled that situation badly, and I would do things in a very different order if a similar situation arose today. Regardless of my social missteps, I did manage to improve 0.999... in several dimensions, and I'm not talking about citation count. In the end, everybody congratulated me on a job well done. If you care about results, you can't be sore over that article. Melchoir 00:53, 10 March 2007 (UTC)
Behold a stark demonstration of the folly of arguing with foil-wearers; their inner voices overwhelm the sounds from outside. In his mind, the problem is not his bizarre idea of what falls under WP:OR, but merely his social skills in failing to convince all those who disagree. And he goes on to insist (to me, no less) that he "improved" the article and that everybody offered congratulations! It may seem harsh to refuse to debate such a person, but in fact it is hopeless to try. --KSmrqT 12:02, 10 March 2007 (UTC)
My idea of what falls under WP:OR was stated and applied to 0.999... in an unpopular fashion. I am sorry for that, although I can't apologize for the outcome.
I have no idea what it will take to placate you on this matter. I, and at least one other editor here, have attempted to discover what elements of the old version you would like to restore, and why. To no avail. I've tried to explain that I learned from the experience; you choose not to care. Apparently even the passage of time has done nothing, and you have expressed no wishes for the future. Is there anything that might convince you to stop cherishing an old wound?
And in the event that you refuse to acknowledge that question, what do other people think I should do? Melchoir 20:57, 10 March 2007 (UTC)
Whatever the case, we can hopefully agree that Étale cohomology needs some references, if only for further reading. Also, some form of acknowledgement of the intellectual achievements of the founder(s) of the theory (Deligne? Grothendieck? Serre? Verdier?) would seem in order.  --LambiamTalk 13:42, 9 March 2007 (UTC)
Charles Matthews wisely stayed out of the fray and added two. (Actually, the article already referred to SGA 412, with a link to our article which has extensive bibliographic information.) I have fleshed out the first two references, added more, cleaned up the equation formatting somewhat, and inserted a passing mention (per Springer) of the Künneth formula. I have not made any attempt to review the content of the article, for which not even 200 references can substitute. I would far prefer to see those who know the topic well devote their time to that than to peppering the article with citations. In that spirit, I thank Charles Matthews and R.e.b. for creating the content in the first place, with or without references. --KSmrqT 00:05, 10 March 2007 (UTC)
KSmrq, please note that your motivations may differ from others. Whenever I write about topics that I know very well, I rarely add references, because I simply don't have them any more; I'm working from memory. I think this describes others who write on topics they know well (e.g. Charles Matthews). However, I don't much like writing about things I know very well (they bore me; I do so only out of pity for some sad article); I prefer writing about things I am learning/re-learning/reviewing. These are easy to cross-reference, because I have three texts in my lap all at once. The result is a referenced if perhaps inelegant/stilted article. So it goes. linas 00:55, 10 March 2007 (UTC)
Good point. Here's another. Some topics that I know too well I avoid touching here as much as possible, because I know what can happen to them. The little warning at the bottom of the page says "If you don't want your writing to be edited mercilessly …, do not submit it." Too true. But, motivations aside, you have repeated the two modes of creation I described early. And, as I said, I am in favor of both. --KSmrqT 12:02, 10 March 2007 (UTC)
Gee, Linas. You must have a big lap. Or some skinny textbooks. Maybe both? ;^>
I think I can see both sides of this issue. On the one hand, if a relatively simple mathematical idea is explained well, there's hardly any reason to give a reference; either the reader is going to understand say Euclid's proof that there is no largest prime number, or else he hasn't got a future in mathematics. On the other hand, well-written articles about less familiar topics begin to look too much like OR if they don't contain at least a couple of references.
Today I spent some time researching the Hartman-Grobman theorem. I had never heard of it before, but it seemed intuitively appealing, once I understood it. I figured that the best references would not only explain the theorem – they would also indicate how the theorem got its name. Eventually I found what I was looking for. I found an open on-line copy of a contemporary peper that builds on the result of P. Hartman and D.M. Grobman, and also cites the original papers (from 1959, and 1960). I also added the references to the older papers, only one of which is available on-line (via JSTOR, and therefore not freely available to most readers).
There, I think, is the rub. An awful lot of good math papers are available on-line, for $24 a pop (unless you're a subscriber to JSTOR, or IEEE, or ACM, or Springerlink, … or you have free access somehow). Most of our readers aren't in that boat. So finding good references for a free on-line encyclopedia is a challenge. Maybe we ought to focus more on helping each other solve that problem and worry a bit less about the exact number of references a given article theoretically ought to have. DavidCBryant 02:59, 10 March 2007 (UTC)
The irony of the distortion of my remarks is that I explicitly said I like references, properly used. And as the Hartman-Grobman research story reinforces, it often takes considerable time and effort to track down the ones we want.
I may be deluding myself, but I have the impression that I am often more successful at locating information on the Internet than are many around me. Search strategies can make a big difference.
  • For example, if I search for 'Hartman-Grobman theorem' I miss the sources that reverse the names. If I omit the hyphen, as in 'Hartman Grobman theorem', I get both orders. In either case the information I want may be drowned in a sea of irrelevant hits; an effective response is to insist on the phrase, '"Hartman-Grobman theorem"', not just the individual words.
  • Soon I find that Hartman (1982) published Ordinary Differential Equations, 2/e, Birkhäuser, alleged to contain the theorem. If I have a good library or bookstore nearby, perhaps I can have a look, as it seems likely to be a good reference. Otherwise, it's back to the Web. But wait, perhaps it's on Amazon.com, and anyway I'd also like the ISBN.
  • So I search for 'Hartman 1982 "Ordinary Differential Equations" ISBN'. Notice that the title is quoted and the ISBN is explicitly requested; in my experience both of these small details are remarkably helpful in quickly locating exactly what I want. Also, here the date helps me restrict to the second edition (and is more effective than trying to say "2nd edition"). I discover that SIAM reissued the book in paperback in 2002, March 4, with ISBN 0898715105, and that the author's first name is "Philip".
  • Using this handy online tool, I quickly obtain a correctly hyphenated ISBN-13, namely ISBN 978-0-89871-510-1. Sometimes we get lucky, and Amazon lets us browse inside a book; not so here, but it's a tip worth remembering, especially when all we need is a page or two. (Another tip is to look for author preprints of journal papers.)
  • Nothing I have described so far requires any subject knowledge. Sometimes that can make a dramatic difference as well. For example, this seems to be a not-too-exotic topic in ODEs, and I can locate this online book by Gerald Teschl, which discusses the theorem in §7.3. Incidentally, I deliberately did all this without looking at what DavidCBryant chose for the article.
This by no means exhausts strategies, but perhaps it gives a feel for the hunt. It is time-consuming, even online, and sometimes frustrating. There is no guarantee that any good reference is available, no matter how hard we look, for a variety of reasons. In fact, we have not discussed how we judge "good", except implicitly to prefer material that is freely available on the Web.
Both linas and DavidCBryant have told us that successfully researching, learning, and explaining a topic can be gratifying; I concur. I would add that even researching a familiar topic can bring pleasant surprises, as every day more material — both old and new — shows up on the Web. Sometimes one also has the guilty pleasure of discovering that one's own work has been put to new uses.
Let me conclude with a brief mention of how I have been writing up references. My primary guide has been WP:CITET. Although these templates are more verbose than just typing in the data, they spare me the trouble of consistent formatting, and help other editors do the same. I am currently trying the {{citation}} template, which covers books and journals and so on all together. It also supports automatic links from {{Harv}} (and {{Harvtxt}}) citations, the style I prefer. (Am I the only one who hates microscopic lists?!) It's too bad we don't yet have a Wikipedia-wide BibTeX system, but apparently the rest of the world still struggles to catch up with standard practice in the mathematics community. ;-)
One last tip: AMS may be able to help decipher those mysteriously abbreviated journal names, with this online guide.
Example: In the theory of ordinary differential equations, the Hartman–Grobman theorem, as described by Hartman (2002), characterizes solutions in the vicinity of a hyperbolic fixed point (Grobman 1959).
  • Grobman, D. M. (1959), "Homeomorphism of systems of differential equations", Doklady Akademii Nauk SSSR (in Russian) 128: 880–881, ISSN 0002-3264 
  • Hartman, Philip (2002), Ordinary Differential Equations (2nd ed.), SIAM, ISBN 978-0-89871-510-1 
(Incidentally, I have used an en dash, not a hyphen, in the theorem name — a stylistic nicety.) Enjoy. --KSmrqT 12:02, 10 March 2007 (UTC)


(KSmrq's comment and mine are both pretty long and have the same indentation level, so I'm putting this line here to separate them. The following comment is mine, Sopoforic's)
DavidCBryant notes that many of our references are not available (to most people) for free, online, and suggests that we work to overcome this. I think that a part of this would involve collecting a list of useful online sources, of which I know there are a few (Diestel's book Graph Theory comes to mind, for that subject). A second part, though, would be providing access to those sources which are legally available, but not practically available. I have occasionally cited works that are in the public domain due to their age, but which were rather hard for me to acquire, due to being in storage, or only available through ILL, or on microfilm, or whatever other difficulties may arise. We could conceivably provide access to these sources by scanning them and linking, but I personally am not sure how I would go about it--supposedly commons is the place to go for things like that, but they don't support PDFs, and JPGs of individual pages aren't as helpful as I'd like.
I don't know whether others would be willing to put in the extra time to scan out-of-copyright sources, but I wouldn't mind doing it, if only I knew what I ought to do; it's a crime that so many public domain works are locked up in subscription services, but without some guidance, I can't help solve that. So, does anyone have any recommendations? I've access to a scanner and a university library, and I've got enough free time to scan things in. If someone will help me to learn what I ought to do, I'd happily scan in relevant sections of books and things.
But that is only one idea. I'd love to hear any suggestions others may have. --Sopoforic 21:37, 10 March 2007 (UTC)
Thank you for the generous offer. There are some details we would want to discuss (proof of copyright status, where to store, format — DjVu+OCR or PDF, cataloging, overlap with existing sources), but let's begin with: can you point us at an online catalog for the library?
Meanwhile, here are three links that may be of interest: Cornell monographs, Internet archive, UPenn list. --KSmrqT 22:31, 11 March 2007 (UTC)
I attend West Virginia University, and the catalogue is here; I believe it is accessible to the public. Of course, I'm not limited to only those books/journals owned by this library. I can also request these things via ILL, so in practical terms I can probably get access to any article or book published after about 1850 (in fact, it would probably be easier for me to get journal articles that aren't owned by the library, due to a number of factors, although that is no strict statement). Actually, I don't know what the license for JSTOR is like, but they have many articles that are out-of-copyright; if the license permits, I (and others, I'm sure) could post those articles somewhere also. I'll get in contact with whoever is in charge of the JSTOR license at my school and see what's what. --Sopoforic 03:52, 12 March 2007 (UTC)
I have the impression that JSTOR already allows public access to out-of-copyright material, and that it only restricts more recently published content. At least, I haven't always had to go through my campus's VPN to gain access to old papers on JSTOR. —David Eppstein 05:12, 12 March 2007 (UTC)
It doesn't seem that it is. I just had someone check who isn't on the campus network, and he got a copy of the first page of the article and a message telling him to subscribe for access. For reference, I gave him this url to an article in the first issue of the American Journal of Mathematics, from 1878. --Sopoforic 05:35, 13 March 2007 (UTC)

I've finally got round to creating a Wikipedia:WikiProject Mathematics/Resources page. The aim of this page is to list good sources to help in referencing of mathematics articles. --Salix alba (talk) 09:44, 12 March 2007 (UTC)

LaTeX to Wikicode translation

A raw version of a translator is available, by joint effort of User:Oleg Alexandrov and myself. Jmath666 06:57, 25 February 2007 (UTC)

"Joint work" here means that I did the original hack of several lines and then Jmath666 took the effort to make this actually output something usable. This is an interesting way to create articles, surely much faster and more efficient than using the textbox and the "Preview" button. Oleg Alexandrov (talk) 07:08, 25 February 2007 (UTC)

If you insist on getting inline TeX out of this thing, can you at least use \scriptstyle when it's inline? Michael Hardy 03:15, 28 February 2007 (UTC)

Please explain. Jmath666 22:18, 8 March 2007 (UTC)
How about the reverse - Wikicode to LaTeX? Tompw (talk) 16:25, 1 March 2007 (UTC)
The basic stuff (sections, equations, <ref></ref> to \bibitem, but no pictures or links) would not be so hard either. I wanted LaTeX to Wikicode translator for myself, because over time I wrote some introductory material in LaTeX that may be useful. And citations are so much easier if I can just pull them from existing BibTeX databases. Jmath666 22:18, 8 March 2007 (UTC)
Not even speaking of the convenience of a wysiwyg editor instead of hacking the source. Jmath666 01:20, 9 March 2007 (UTC)

By the way, is there some permanent place to make a link on Wikipedia to such tools? Jmath666 22:18, 8 March 2007 (UTC)

There is now a separate user page for the translation. Jmath666 00:09, 15 March 2007 (UTC)

WikiProject

I've started something called the Mathematics Construction WikiProject (not in development yet), which focuses on making sure that information on an article is verifiable and attributed with reliable sources. If we can do something like this on this WikiProject, it'd be great! Sr13 (T|C) 03:03, 10 March 2007 (UTC)

Um… starting a whole new WikiProject might look suspiciously like a schism. How about making it a "department" of this Project instead, something like the examples at Category:WikiProject peer reviews? Wikipedia:WikiProject Military history seems to be pretty well-organized. Melchoir 04:44, 10 March 2007 (UTC)
Sure, that would be a great idea! Sr13 (T|C) 09:34, 10 March 2007 (UTC)
Not a good idea, unless you are looking for political trouble. Instead, focus on making sure the information in each article is correct and complete, with references that follow our guideline. That is what we really want, while what you propose is a controversial Wikipedia methodology that pretends to be equivalent. Empirical studies have shown that the more inline citations an article contains, the less likely it is that anyone will actually verify everything. (OK, so I'm not aware of any actual studies; but I feel confident that's what they would find.) We must also guard against the bystander effect. I find it telling, and troubling, that you did not propose that articles actually be verified. This is cargo cult behavior. --KSmrqT 12:39, 10 March 2007 (UTC)
Making sure that an article is correct and complete is surely the most important consideration when deciding how to reference an article, but it is not the only thing that "we" really want. Articles should also be written to be robust against the introduction of error by future editors, to simplify accuracy disputes on talk pages, and to aid our readers in their own research. These goals are the responsibility of an interactive encyclopedia, and they aren't met just by producing a version of a given article that is true.
Given that we don't have empirical studies yet, why prejudge Sr13's idea? The worst that could happen is that the department is ineffective and gets shut down. Melchoir 00:10, 11 March 2007 (UTC)
I see...so what you are saying is that verifying should not be a specific group's commitment, but rather each Wikipedian's obligation, and this is what makes an interactive encyclopedia. Sr13 (T|C) 08:45, 12 March 2007 (UTC)
I think Melchior is actually supporting your idea. KSmrq is concerned that your project will result in a lot of articles being given the appearance of having passed through a sort of verification process when in fact they may simply have had some minimal references slapped on (or, so as not to impugn your efforts, it may be that they are properly referenced, but then later dramatically expanded, and no one adds references because "they are already there" but in fact inadequate). I, however, also think it may be a good idea to do what you propose, and for a reason KSmrq already gave: the bystander effect. I for one know that I almost never go out of my way to add references to an article with none. However, I just went on an improvement binge at triangulated category because I thought the references section was poorly written, which resulted in my adding several references in addition to reformatting the existing ones. If people all look at an unsourced article they will all think that someone else should do it, but if we have even badly sourced ones, then the inevitable tendency of people to boost themselves by correcting mistakes will lead more of them to add references. Plus, we'd have at least some references, and even if they barely support any of the claims of the article, they are at least useful for people who come to a page hoping that, if it doesn't say anything useful, it will at least give them another place to look. Which most of our articles don't really do now. Ryan Reich 21:17, 12 March 2007 (UTC)
KSmrq's cargo cult idea lit up my imagination: just like a coconut radio carved by a primitive tribe might start working if only its only carved realistically enough... "if we can only add enough ref's, then surely any article can become become factually correct..." .. this thought made me smile. Not understanding that high-tech is important for creating a functional transistor radio is like not understanding that meticulous research is needed for factual accuracy in an article. Just adding references is not enough to make it true.
It took me a bit to understand the bystander effect: just as a mob of bystanders will fail to help a victim in need of help, so an article that is obviously in failing health and factually incorrect might not be helped because it already has so many references and footnotes "standing by"... . linas 00:35, 13 March 2007 (UTC)
It depends on how you interpret the crime in this case how you can apply the bystander effect. KSmrq and you both seem to agree that having so many references "standing by" will cause people to neglect their duty to do some real research on the article. It is certainly the case that in order to take a generic math article and elevate it to something that even Brittanica would be proud to publish will take a lot of work, and that adding piecemeal references will not contribute to this. Most of our articles are not near this state, however, and in fact have no referneces at all. Even adding standard citations (you know, putting Hartshorne chapter and verse in every basic algebraic geometry article) will at least improve them to the point that they are useful as references. At least they will tell you where you might go. It will also provide a basis for further improvement, which brings me to the other interpretation of the bystander effect: I claim that in this case, the crime is indifference and that we are all bystanders, no one making even a first attempt to do something useful in the way of references. Even your and KSmrq's objections to this project (something like "people should improve articles deliberately") reflect a bystander effect: you want editors to self-select to be the one to "save" the article. But it seems to me that the philosophy of Wikipedia is that multiple incremental improvements will lead to a high-quality product, not that an article is not worth being written if it is not going to be written perfectly. I think we should not stand in the way of someone hoping to industrialize the process of making initial increments in citation. Ryan Reich 03:02, 13 March 2007 (UTC)
I have pretty much every math logic article on my watchlist; many of them are in a bad state. I can say from experience that bystanders do make edits to correct errors in these articles; many errors are corrected by anonymous IP editors or by newly registered users with very few edits.
You might be interested in this list of unreferenced math articles. I think it is unreasonable to go through and add references I have never looked at to articles whose content I am not completely familiar with. But I think it would be very appropriate, for example, for someone with a background in algebraic geometry to go through those articles. I would add the crucial caveat that the topic of the article should actually be discussed in some depth by the references added. CMummert · talk 18:56, 13 March 2007 (UTC)
Even if you're not familiar enough with an article to verify it against a reference, you could always add potential sources under a "Further reading" section. Melchoir 19:51, 13 March 2007 (UTC)
Yes, I didn't think about that. The key distinction I make is whether the editor has actually seen the reference or not (at least an online version); I feel very bad adding references to books whose existence and content I am taking on faith. CMummert · talk 13:44, 14 March 2007 (UTC)
Potential sources? I can just see it: thousands of Wikipedia articles chock-full of potential facts "verified" by citing the entire contents of the Library of Congress as potential sources.
Standard rules in academia say if you haven't personally used the original source, even if it is just a reprinting (and especially if it is a translation), you should acknowledge the source you did use; otherwise we risk a game of "Rumors". This proposal goes far beyond that nuance, into total madness. "Potential sources" is a potential disaster. Kill it now. --KSmrqT 05:14, 15 March 2007 (UTC)

Formatting of categories

Is there any consensus how to format categories? Sometime one sees \mathbf A (mathbf) or A, sometimes \mathcal A (mathcal). Jakob.scholbach 22:49, 13 March 2007 (UTC)

And worst of all, in some articles (e.g. monoidal category) one sees \mathbb{C}. Ryan Reich 04:48, 14 March 2007 (UTC)
To add to my comment. \mathbb{C} is clearly wrong because it conflicts with well-established notation (my personal opinion is that blackboard bold should be reserved for well-established notation, which is essentially exclusive to the various number sets \mathbb{N}, \mathbb{R}, \mathbb{C}, \mathbb{A} (the latter is the adele ring), and so on). There is a reasonable case that A is preferable to \mathbf{A} on account of typesetting aesthetics (and an equally reasonable case that the opposite is true on account of the fact that the latter reflects a semantic distinction, namely "math variables", whereas the former is merely formatting), whereas \mathcal{A} can be said to be preferable on account of being unlikely to conflict with anything at all (calligraphic characters are, as far as I know, not standard notation for anything, whereas bold characters are not infrequently stand-ins for the equivalent blackboard-bold character). I would endorse either A or \mathcal{A} without preference (though of course consistently in an article) given that the overlarge PNGs we get from TeX markup are actually quite distracting. Ryan Reich 05:04, 14 March 2007 (UTC)
My preference to denote categories is sans-serif boldface, Cat.
Please note that we do not have enough alphabet and style variations to give every type of entity in every specialty its own unique look. My choice, for example, conflicts with the recommended substitution of bold for blackboard bold inline, as in R instead of \reals\,\! for the real numbers. We try to write each article as clearly as possible, adapting notation where we must, and trusting our stalwart readers to compensate for our inadequacies. --KSmrqT 05:21, 15 March 2007 (UTC)
Yes, this is my preference, too. \mathcal is problematic with categories like Ab and for things like the reals the \mathbb seems to be much more often used than \mathbf. Should a recommendation be part of the style-guideline of math-papers? Perhaps it is also possible to introduce a tag like \cat{...}, at least in the Latex code. (If I write a paper in good old-fashioned offline Latex, this would be the first I would do. If I later need to change the layout, this is done by changing one line of code). Jakob.scholbach 16:11, 15 March 2007 (UTC)

Inductive symbol

Has anyone ever heard of this? Or should we put it up for deletion as un-notable? JRSpriggs 06:18, 22 February 2007 (UTC)

I'm from Australia and I've never come across it. darkliight[πalk] 06:35, 22 February 2007 (UTC)
We also find in the article:
  • Spoke 4: The portion of the number system for which the proof holds, e.g. n=J+ (positive integers)
Universal notation for integers is Z, not J. The creator contributions consist solely of this article, this image, and a new section about it added to mathematical induction (since removed). The image should die as well. --KSmrqT 09:51, 22 February 2007 (UTC)
Spacepotato (talk · contribs) un-PRODed inductive symbol without any explanation or substantive change. JRSpriggs 08:35, 27 February 2007 (UTC)
Well, you can do that -- prod is supposed to be for noncontroversial deletions, so anyone who objects can remove it. Just means you have to go the long way around, unless there's a speedy criterion that fits. At a three-second glance the article looks like a goner, but I haven't put any more effort into it than that, so who knows. --Trovatore 08:40, 27 February 2007 (UTC)
Not that it matters much, but Spacepotato is apparently part of a crew that goes around un-PRODing everything that's proposed for deletion. Why, I'm not sure. DavidCBryant 01:16, 28 February 2007 (UTC)

Oh, a propos of nothing much, I do recall the "J" notation for the integers, from high school. I think the Houghton–Mifflin series of books use it. --Trovatore 08:42, 27 February 2007 (UTC)

I tried to put it up for deletion at WP:AFD (which I have never done before), but I think that I messed the process up somehow. Can someone fix it, please? JRSpriggs 09:58, 27 February 2007 (UTC)
The AfD process seems to be in order. I would suggest an effort to clean up mathematical induction which is not much better than the this one. The intro has too many advanced topics. The informal statement should state induction for the positive integers, not infinite sequences. The worked out example unnecessarily introduces the confusing notion of an empty sum (just start with n=1), and the rest of the article is an unorganized jumble of ideas.--agr 00:12, 28 February 2007 (UTC)
As you can see at Wikipedia:Articles for deletion/Inductive symbol, it was deleted. And now, its associated image is also up for deletion as an orphan image. See Wikipedia:Images and media for deletion#Image:Inductive.gif (see old discussions for March 4). JRSpriggs 04:56, 8 March 2007 (UTC)
The image itself was deleted[18], although somehow the image page still exists.  --LambiamTalk 09:51, 15 March 2007 (UTC)
I have to agree with agr that the mathematical induction needs cleaning up. The current mess is a disgrace! It should focus on the simple case of induction on the natural numbers, possibly also including structural induction, but all talk of transfinite induction needs to be moved to the transfinite induction page. Which also could use some cleaning up, but that is a topic for talk:transfinite induction perhaps. I admit I am hesitant to dive in and do something here; afraid of sticking my hand in a wasps' nest. Hanche 17:54, 17 March 2007 (UTC)

Back to manual archiving

I removed the Werdnabot invocation. I have been following Werdnabot closely; and it just has too many bugs that manifest themselves in unexpected ways. Like on Tuesday, it did not put any edit summaries into its edits for no apparent reason. Thus we go back to manual archiving. JRSpriggs 08:10, 7 March 2007 (UTC)

By the way, Werdnabot (talk · contribs) has been down (blocked) and appears likely to stay that way. However, there appears to be another bot that we might use for archiving — MiszaBot II (talk · contribs). Has anyone had experience with MiszaBot? JRSpriggs 09:07, 16 March 2007 (UTC)
I looked into it a little yesterday because it looks promising. The code is still under development, and the bot was speedily approved when WerdnaBot was discontinued. The talk page User talk:Misza13 shows one or two bugs in the last two days. So maybe we should wait a couple of weeks until the kinks are worked out. CMummert · talk 11:43, 16 March 2007 (UTC)
OK. And thanks for doing the manual archiving here. JRSpriggs 07:13, 17 March 2007 (UTC)

Silly pictures

2 or 3 years ago, before Wikipedia was as popular/well known/... as now, I looked at the Mathematics and Computer Science articles and was extremely impressed. I remember noting a correction of a fault in a Taylor/MacLaurin series. It was no more than minor proof reading but within a day somebody had replied "True, why didn't you correct it yourself?"

A couple of years on it all seems to be going seriously downhill. Hard to believe but it just might be better to divide the subject into "Mathematics" and "Popular Mathematics". In the Mathematics section there are NO links to JAVA/COBOL/IGNORANT animations - that sort of nonsense can be viewed in "Popular Mathematics".

2 more possible rules -

  • No pictures unless it is Euclidean Geometry.
  • No links to Tom, Dick or Harry's website.

Colin M Davidson 62.251.121.16 20:01, 12 March 2007 (UTC)

I do tend to agree about the animations. While they do add value in explaining some points, they can also be very distracting and constantly draws the attention. The other day I removed an animation Image:Vortex-street-animation.gif from spiral only to find that it was actually a featured picture. I've been thinking about ways to present the animations without them being distraction, posibly with a sub-page or with a show/hide box. Animations also gobble up bandwidth. --Salix alba (talk) 21:53, 12 March 2007 (UTC)
Its not just pictures or animations. Popular math articles tend to accrete a varity of unhelpful, cloudy, useless statements, formulas, and templates, and not just bad pictures or websites. This is particularly true for any subject that is "hard" and has a cachet, such as Einstein's theories about spacetime, or quantum mechanics. It seems that novices wish to demonstrate thier ability and intelligence by "improving" these articls in dubious ways, garnering bragging rights by having "written" the WP article on general relativity. (Careful: this is exactly the same thing that the experts do; only that experts get fuzzy at a higher, more abstract level).
I think the Essjay/Jimbo Wales accreditation issue feeds into this. The difference is that I think the only viable mechanism is to have "stable versions": allow this wikiproject to mark a particular version of an article as "acceptable", whereas other version are caveat emptor. linas 00:55, 13 March 2007 (UTC)
"No pictures unless it is Euclidean Geometry" - are you serious ? Would you really remove the images from bifurcation diagram, elliptic curve, blancmange curve, catastrophe theory, topology, braid group, pretzel knot, crosscap, Möbius strip, Klein bottle etc. etc. ? I think these articles would be much poorer as a result. Gandalf61 13:57, 13 March 2007 (UTC)
What about this: An essentially technical article should only have illustrations that help to understand the material presented in the text. As always, such a rule should not be applied rigidly, but the tendency to add images just because it looks good, however tenuous the connection, should be countered.  --LambiamTalk 14:34, 13 March 2007 (UTC)
I have no idea what the original poster meant by "no pictures unless..." as that is clearly ludicrous (and also casts doubt on the rest of his statements). What you say is more reasonable, but I would be averse to such a rule at all. Is the adding of images really a problem? It seems to me there really is a lack of images, especially ones that "look good". Many math animations I've seen, such as at dunce hat (topology), have added considerably to the article. Perhaps this is all in reference to some problem I've not come across, like people adding a picture of Britney Spears holding a doughnut to solid torus. --C S (Talk) 15:33, 13 March 2007 (UTC)
I should add that my favorite example of an image whose inclusion has seemed ludicrous to more than a few but in my opinion is actually instructive is the cartoon in Bring radical. Perhaps this is more along the lines of what the OP thought was taking Wikipedia downhill. --C S (Talk) 15:40, 13 March 2007 (UTC)


2nd and last attempt to remove silly pictures.

Klein's bottle (or surface) is historically important. There should be some reference in any self respecting body of knowledge. - More so if it has lead to an interesting branch of mathematics. I am very disturbed by the "silly picture". The picture is 2nd rate (JAVA/COBOL?) and very misleading. We can only be grateful for the writer's text - something along the lines of "But don't try to do this in 3 dimensions."

Restricting pictures to Euclidean geometry is clearly extreme but it seems a better starting point than accepting anything that Tom, Dick or Harry throws into the mill.

Colin M Davidson 62.251.121.16 20:42, 15 March 2007 (UTC)

Which image specifically in the Klein bottle article do you find "silly"? I take it you don't mean the still frame from Futurama since your objection is to a computer-generated image. (How does one use COBOL to generate an image, btw?)
And what about the images is "very misleading"? That the images in the article depict immersions of a Klein bottle? The use of immersions is made rather explicit in the text and in the caption to the first image. Lunch 21:37, 15 March 2007 (UTC)

When you put quotation marks around the words "silly picture", that means either that someone called it that or that someone would call it that but you wouldn't. Yet your words make it appear that that's not what you meant. Michael Hardy 23:50, 15 March 2007 (UTC)

I'd also find it easier to understand if Colin M. Davidson would say WHICH picture he has in mind. Michael Hardy 23:56, 15 March 2007 (UTC)

I can't tell which picture Colin M. Davidson is talking about since they all look good to me. The top one is the standard image of this particular surface, looks like it was done with Mathematica, illustrates exactly the key feature of this immersion. Aside from the two other Mathematica pictures, we have a square-folding diagram, a photograph of a "real" Klein bottle, and the Futurama comic. I find the other two Mathematica pictures quite useful, though the one illustrating dissection of the Klein bottle into two Möbius strips could, I suppose, use a better angle; in particular it's nice to have alternative embeddings shown in the article since, as it is impossible to depict the surface accurately in three, let alone two dimensions, and only one picture. Really, the pictures may be the best part of the article, especially for someone interested just in an overview of the surface. Ryan Reich 00:24, 16 March 2007 (UTC)

The figure-eight one is really a little hard to follow. I can't see where the self-intersection is supposed to be. To me it just looks like a torus where someone grabbed a bit of it and turned it 180 degrees. --Trovatore 00:56, 16 March 2007 (UTC)
You might find it helpful to start with a cylinder with a figure eight base: 8 x [0, 1]. Now glue the top to the bottom but with a half-twist so that opposite parts of the eight get glued together. Also helpful to see this last part is to orient the top and bottom 8's in opposite directions. The twist makes sure the orientations match in the gluing. --C S (Talk) 01:26, 16 March 2007 (UTC)
OK, I can see it now. --Trovatore 01:35, 16 March 2007 (UTC)

From Colin M Davidson's other edits and remarks (e.g., at Talk:Dijkstra's algorithm#EWD would have cried) I deduce that he might be referring to the 'external links' of the Klein bottle article. (Indeed, they lead to one animation and one home page.) Colin, if this is correct, you could have said so from the beginning... The natural thing was to look for pictures in the article itself, since this is what your text seemed to indicate. JoergenB 20:17, 17 March 2007 (UTC)

Symbols in non-latex code

Is there a page depicting all commonly used symbols like ℤ or ∪ (not in the < math >... < / math> environment) -- and also how to type them? It always takes me an eternity to find them on other pages like union (set theory) etc. Thanks. Jakob.scholbach 16:13, 15 March 2007 (UTC)

Try User:KSmrq/Chars. —David Eppstein 16:35, 15 March 2007 (UTC)
Some are also in the edit characters below the edit box. —METS501 (talk) 20:46, 15 March 2007 (UTC)
Yeah, but wouldn't it be better to use the < math >... < / math> environment, and let the mathml convert these to the proper symbols? That way, at least one gets a uniform look-n-feel. linas 23:34, 15 March 2007 (UTC)

No, it wouldn't always be better. If we were using TeX in the normal way, it would be better. But often on Wikipedia when TeX is inline, it gets misaligned or is far too big with comical effect. Michael Hardy 23:48, 15 March 2007 (UTC)

Agreed, for Wikipedia in the present state. But hopefully the rendering of math formulas will be fixed in due time and hopefully Wikipedia will be around for a long time. So it might be better to do the right thing and expect it will look good eventually even if it looks bad right now. In other words, the problem is incorrect rendering of math formulas in the web environment; ad-hoc fixes will only make it worse in the long run. Jmath666 03:02, 16 March 2007 (UTC)
J.M.Keynes said, "In the long run, we are all dead." I think we ought to make the pages look as good as possible right now. If the graphics engine ever gets fixed, the in-line HTML will still look OK, and it will be relatively simple to cut everything over to TeX. So we can either (a) make it look OK now, and better eventually, or (b) make it look bad now, and better eventually. Which makes more sense? Think of the readers! DavidCBryant 17:03, 16 March 2007 (UTC)

CMummert for admin

I nominated one of us, CMummert, for admin. If you are familiar with his work, you can comment/vote at Wikipedia:Requests for adminship/CMummert. Oleg Alexandrov (talk) 03:16, 16 March 2007 (UTC)

Uniformization of notation at Cyclic group

New user Greg Kuperberg is giving Grubber a hard time at Talk:Cyclic group, arguing about the best notation to use in the article. It seems Greg Kuperberg wants to push for a certain notation because he uses it and it is used in some current research papers.

My understanding of wikipedia policy is that we always use the most common notation. We copy standards, we do not create them. For articles in mathematics, the most common notation is the notation used in authoritative textbooks on the subject. Perhaps someone can point me to a relevant wikipedia policy or provide some backup for Grubber. MathMartin 16:50, 16 March 2007 (UTC)

There isn't an explicit policy on math notation (but see WP:MSM). You are correct that we describe the "real world" rather than recreating it here. So if there are multiple common notations in the real world, we should just describe them, pick one to use, and get on with things. Discussion on the "best" notation tends to go around in circles. In this case, it looks like both involved parties agree that Z/nZ is acceptable. CMummert · talk 18:28, 16 March 2007 (UTC)
Uh, Kuperberg has been editing here under that name since 2004, judging by the history of his talk page. He's hardly a new user. —David Eppstein 05:07, 17 March 2007 (UTC)
Yes, he is not a new user. I should have checked more thoroughly. MathMartin 13:21, 17 March 2007 (UTC)
Hmm. There is a Greg Kuperberg who claims to have coauthored a paper with you, "Fat 4-polytopes and fatter 3-spheres". On the down side, he claims to have a doctorate in mathematics from U.C. Berkeley, which may have brutalized his sanity; and U.C. Davis has a well-known enology program, which may also have had adverse effects. Any comments on his sanity or sobriety from your experience? ;-) --KSmrqT 06:44, 17 March 2007 (UTC)
I don't recall that I've met him in person, just corresponded electronically on that paper and other matters. I have no reason for thinking him any less sane or sober than the typical mathematician. —David Eppstein 06:49, 17 March 2007 (UTC)

Proposed deletion of "list of cycles"

See list of cycles and Wikipedia:Articles for deletion/List of cycles. Michael Hardy 22:24, 18 March 2007 (UTC)

A-class review proposal

As several editors have expressed an interest in it, I have created a proposal for an A-class review process for this project. If you are interested, please discuss it at the associated talk page. CMummert · talk 00:36, 6 March 2007 (UTC)

We now have the first article for review Addition see Wikipedia:WikiProject Mathematics/A-class rating/Addition. --Salix alba (talk) 10:14, 9 March 2007 (UTC)

I have moved the proposal to Wikipedia:WikiProject Mathematics/A-class rating. Please feel free to nominate articles! CMummert · talk 13:08, 20 March 2007 (UTC)

Rating importance calibration

We've been having a discussion on calibration of the mathematical importance rating system over on Talk:Penrose tiling that might be of more general interest to the participants here. —David Eppstein 18:40, 17 March 2007 (UTC)

Using the criteria set forth there, I am tempted to say that Limit (mathematics) has top or high importance, not the mere mid importance it has been dealt.  --LambiamTalk 20:11, 17 March 2007 (UTC)
I agree, as one of the foundations of calculus and many other uses, high seems to be the appropriate value. I've changed the template accordingly. --Salix alba (talk) 22:04, 17 March 2007 (UTC)

David: Your proposed criteria at Talk:Penrose tiling seem excellent at first, but I am worried about them. It seems to me that the principal criterion you have offered for judging the importance of an article is whether you would be embarassed to find that the article was not in the encyclopedia. This seems initially like a reasonable idea, particularly since your examples all elicit about the same level of embarrassment for me as you say they would for you. But I worry that not everyone will be similarly embarrassed by the same things.

If personal embarrassment is used as a criterion, and if there is a consensus about the degree to which individuals would be embarrassed by the hypothetical ommission of articles, then all is well. But I fear that using embarrassment as a criterion will only turn the vague and subjective arguments about "importance" that we have now into equally vague and subjective arguments about personal embarrassment. Nothing will have been gained, and perhaps it will be even worse, since the terms of the discussion will encourage participants to rant and flame about about their personal emotions. Consider how much worse it would be to describe the importance of an article in terms of the rage and fury you would feel if the article were omitted---it should be clear that this way of framing the issue would be unlikely to promote respectful, rational discussions. Using embarrassment as the measure, rather than of rage, would ameliorate the potential problem here, but not eliminate it, I think.

I do not have a useful alternative to offer, but I am concerned that bringing embarrassment into the official guidlines is a step in the wrong direction, and could turn out to be a grave mistake. I hope that the WP:M community can come up with something less likely to promote flame wars. -- Dominus 13:50, 19 March 2007 (UTC)

I would be happy to have a less subjective scale. But the crucial thing for me is that it should not quantify importance only with respect to current mathematics research or pedagogy, but rather importance as a part of an encyclopedia, taking a broader view of connections to nonmathematical topics as part of that quantification. —David Eppstein 15:16, 19 March 2007 (UTC)
The biography importance characteristics do attempt for something more objective bassed around the importance of the topic cross discipines, top is something like big influance over a wide range of topics, high influence on topics outside of the domain (i.e outside of mathematics), mid influence across a number of fields within the domain, and low being of interest primarially within the field. (or something to that effect) see [19]. I find a certain appeal to adapting this to suit maths articles. --Salix alba (talk) 20:16, 19 March 2007 (UTC)

E8

The E8 (mathematics) lie group hit the news today, which coverage of a full enumeration on the BBC and slashdot, see talk page for links. The article is very technical and could do with some attept to describe it in laymans terms, especially the meaning of the new result. --Salix alba (talk) 20:04, 19 March 2007 (UTC)

This could make a better movie than A Beautiful Mind; read David Vogan's narrative of the project. This site is a good starting point for other info. --KSmrqT 22:44, 19 March 2007 (UTC)
Here's a press-release: http://web.mit.edu/newsoffice/2007/e8.html. Note that Jeffrey Adams, who, as said in that release, is the project leader, has made a Wikipedia account, at User:Jeffreyadams. Nice. Oleg Alexandrov (talk) 03:41, 20 March 2007 (UTC)
Hmmm, compsci heroics. But we need to have more on the mathematics of it. Charles Matthews 10:56, 20 March 2007 (UTC)


Attention: Probability Theory

I was browsing through the list of vital articles, and found out to my dismay that most (almost all) content has been removed from Probability theory. I have already left some comments at its talk page, but I would like additionally to alert as wide a circle of mathematics editors as possible. Arcfrk 03:25, 21 March 2007 (UTC)

Serious work has started on Probability theory. However, we need experts in probability theory and/or statistics to map out the article (urgent) and contribute high quality content (as the time permits). Arcfrk 04:10, 22 March 2007 (UTC)

Sobolev space

I would like to attempt to rewrite Sobolev space. This article, which is quite important, is written in a messy manner (in my opinion). Some points which I would like to stress are described in User:Igny/Sobolev space (they are somewhat mentioned in the article, but like I said it is a mess). In particular I would like to stress the connection to the Fourier transform of distributions, which, by the way, deserves a separate article in my opinion. I will appreciate any input from other editors, in particular a blessing to proceed. (Igny 19:17, 21 March 2007 (UTC))

Yes, the article could be better. If you undertake such project, could you please allow for multiple definitions of Sobolev spaces? Perhaps you could structure it as section "Definition of Sobolev spaces", with subsection(s) for definitions, so that more definitions can be added in future. Because:
  • different definitions do not always give equivalent spaces
  • simple definitions though maybe not as satisfactory have an important place in teaching and are very suitable for encyclopedic purposes. In order of accessibility:
  • definition by completion of a space of smooth function (requires only the concept of completion of metric space)
  • definition by L^p weak derivative (requires Lebesgue integral but neither Fourier transform nor distributions)
  • the distributions/Fourier transform way goes the whole mile but is the least accessible
  • the definition by Fourier series on an interval is a good example for teaching and sometimes a nice trick to know
And yes, distributions should have their own article. So should interpolation of spaces.
Also, it would be good to have at the top of the article something simple yet specific even if maybe not 100% accurate so that people without much background get the correct idea what the topic is (i.e. without knowing what L^p and multiindex are and so on). Many math article are done this way. Maybe something like this: Sobolev space is a normed space of functions. The norm on Sobolev space of order n involves the value of the function as well as its derivatives of order up to n. The Lebesque spaces ... are a special case of Sobolev spaces of order zero. Negative order Sobolev spaces are defined as dual spaces to spaces of positive order, and Sobolev spaces of non-integer order are defined by interpolation of normed spaces (which is not the same as interpolation of function). The importance of Sobolev spaces lies in the fact that the smoothness of a function is measured by in which Sobolev space it is, and solutions of PDEs fall naturally in Sobolev spaces." Then the example of the most common space, H^1=W^{2,2}, in 2D, with all partials written out, and saying that the derivatives are suitably generalized for this whole thing to work, then the TOC and then the messy technical stuff. Thanks for taking this up! Jmath666 01:12, 22 March 2007 (UTC)

Well, I would have to say that the draft article is not written in a very friendly style. We are constantyly asked to have more explanation for the general reader. There is also a constant pressure from experts to remove verbal explanations, replacing them by 'precise' statements and formulae. The difficulty is that articles then lose all chance of access by non-experts. It is fairly typical that an explanatory comment

The Sobolev spaces are the modern replacement for the space C1 of solutions of partial differential equations. In these spaces, we can estimate the size of the butterfly effect or, if it cannot be estimated, we can often prove that the butterfly effect is too strong to be controlled.

was removed by someone in January 2006 claiming it was 'original research'.

Charles Matthews 08:02, 22 March 2007 (UTC)

This is not a draft per se, it is a collection of elements of the future draft. I was just writing things, which the current article lacks or states poorly (again in my opinion). In anyway, I will continue working on my version (make it friendly and so on), which I hope at some moment will be good enough to replace the current version. I just want other editors know about this effort, and contribute with advice if possible. (Igny 13:22, 22 March 2007 (UTC))
Are you sure the desired improvement cannot be attained by a sequence of piecemeal edits – in general a more desirable approach?  --LambiamTalk 14:24, 22 March 2007 (UTC)

Yes explanatory statements for non-experts are needed but the butterfly was a bad one no matter how catchy it sounds; please see the discussion why it was removed. And indeed it was missing references. The reason why Sobolev spaces exist is simply that solutions of PDEs are in general not in the classical C^n spaces. For example, in 2D and 3D linear elasticity, there are functions with finite deformation energy (=solutions of the elasticity equations; Nature settles to the lowest energy state) that are not bounded and so not even in C^0. One can construct such function as a special kind of spike (this makes a nice picture for the non-specialist), which also shows why point constraints make no sense in >1D, even if engineers merrily keep putting point constraints in their Finite element models all the time. Jmath666 15:21, 22 March 2007 (UTC)

Well, I know why it was removed. I don't care about the butterfly. I do care about the general principle of making things comprehensible. And citing OR about helpful heuristics, which are clearly just that and not assertions, is too much on the silly side for me. Everyone knows that some heuristics are 'folklore'. Charles Matthews 18:00, 22 March 2007 (UTC)

I agree. It is very important to make things comprehensible. I do not think the butterfly statement was helpful heuristics, though. More like an attempt to push the right buttons than to give a clue about the subject. And for me at least it sounds so specialized I would have liked a reference. Jmath666 18:25, 22 March 2007 (UTC)

I don't have time to write anything just now, but I think th first chapter of Susanne C. Brenner and L. Ridgeway Scott, "Mathematical Theory of Finite Element Methods", Springer-Verlag, 1994 (ISBN 0-387-94193-2) is a particularly nice introduction to Sobolev spaces. It ought to be accessible to anyone having had a first course in analysis at the level of, say, Rudin or Hewett and Stromberg. Greg Woodhouse 18:34, 22 March 2007 (UTC)

Cross-project help part 2: Concluding Vandalism Study 1

Hello again! Wikipedia:WikiProject_Vandalism_studies's first study is finally about finished. We loved you guys' help a few weeks ago in giving some eyeball time to how the study was composed math wise, and now that we're almost done, we're wondering if you wouldn't mind checking over the results. The study's end results themselves are here, and the discussion of what this means for the conclusions is here. We are keeping in mind that measuring is easy, but knowing what you are measuring is the hard part. Any and all comments, critiques and math angles not considered would be much, much appreciated. We want this to be as tip-top as possible before reporting our findings to the community at large. Thanks everyone. JoeSmack Talk 23:59, 24 March 2007 (UTC)

Attribution

I'm curious what the math community has to say about the proposed merger of several key Wikipedia principles into one: Wikipedia talk:Attribution/Community_discussion. I can't see that it really changes much about the way we do things around here, but I would like to know if there are issues to consider. (Would we have to fight battles over inline citations all over again, for example?) VectorPosse 10:02, 25 March 2007 (UTC)

User:SlimVirgin has written an explanation of why the change was proposed. My personal opinion is that the current wording of WP:ATT is better than WP:V. CMummert · talk 11:25, 25 March 2007 (UTC)
See WP:ATT#How_to_cite_and_request_a_source. We will have to watch this; it used to mandate inline citation, but the present language may be adequate to deal with the inline enforcers. One of them seems to misread it, however, here. You may want to comment on this when you !vote. Septentrionalis PMAnderson 15:16, 25 March 2007 (UTC)
Like SlimVirgin, I see WP:ATT as a needed step forward, if not a panacea. Sadly, there is a heavy thumb on the scales; see these comments by Jimbo Wales. (And, yes, I checked the edit history because his views seemed so startling I wondered if they had been spoofed!)
Perhaps next we can focus on the task of actually checking each article for correctness (and maybe a few other things, such as completeness, clarity, neutrality). Of course, it is meaningless to "certify" an article that "anyone can edit" two seconds later. [If Wikipedia is serious about becoming a trustworthy source, an obvious model is the software community, where lack of reliability can have dire consequences. FreeBSD, for example, is used by businesses that could suffer severe economic and legal harm if their operating system let them down. So, how to allow development and manage the risk? Standard practice is to offer two versions: one "stable" and one "bleeding edge". If you want (or need) to use the latest and greatest features, you may be willing to accept the risk of the experimental version. Wikipedia today gives you no choice. How can a responsible teacher point students to Wikipedia, when at any moment the geometry article, say, might look like this? (Check the edit history; this is hardly an isolated example.)] Happily, efforts are afoot to address this need, so I remain optimistic.
Meanwhile, clearing away Wikipedia's bizarre take on "verifiability" and "original research" can only be seen as a Good Thing (even if we never manage to hunt down and exterminate all members of the "inline citation squad", who insist every statement must have a footnote). --KSmrqT 16:39, 25 March 2007 (UTC)

KSmrq deletion of other's comments

To KSmrq (talk · contribs): Since you appear to be unable to refrain from accidentally deleting the comments of other users, which you did again to Lambiam and Oleg Alexandrov recently, I suggest that you make a practice of checking the revision history after you save your edits and immediately repairing any damage you caused. JRSpriggs 12:10, 25 March 2007 (UTC)

I find it outrageous that you continue to make the daily temperature swing through such excessive ranges throughout the year, with consequent damage from floods and fires; please desist at once or take steps to correct the damage you cause.
Do I make myself clear? Your personal attack is irrational and offensive. If you want results, pressure the developers. I will be happy to work with any developer who wants to track down this issue.
I am fairly sure that the consequences of this bug are far more deleterious to me than to anyone else, and I have already publicized the problem (as you apparently know) and tried a number of changes in practice to try to work around it.
Frankly, it looks like an flaw in maintaining database integrity through multiple overlapping transactions. I don't know if you know anything about the design of database software, but this is the kind of thing that must be carefully built in and regression tested for bugs in any system that is expected to confront such complexity. It is easy to handle one "atomic" transaction at a time; it is much harder to handle multiple simultaneous transactions with unpredictable event sequencing. --KSmrqT 15:04, 25 March 2007 (UTC)

I am not the one who is being irrational here. Nor am I asking you to do anything which I do not already do myself — I almost always check the revision history after I do an edit to be sure that I did what I meant to do. I would also point out that your edits (together with the bugs you mentioned) have caused this problem as often as all other editors on this project put together. A possible factor in causing this is that your edits are often very lengthy, providing more opportunity for edit conflicts. If you want this to happen less often, you could write your messages off-line and then cut and paste them in quickly to reduce the window for edit conflicts. JRSpriggs 05:17, 26 March 2007 (UTC)

Can you take further discussion of this issue to the user talk space?  --LambiamTalk 07:08, 26 March 2007 (UTC)

Academic paper on Wikipedia

I see a reference in Wikipedia:Wikipedia Signpost/Newsroom/Suggestions#Academic paper on Wikipedia to a research paper "Assessing the value of cooperation in Wikipedia" by Dennis M. Wilkinson and Bernardo A. Huberman.[20]. The paper finds that article quality is correlated with both number of edits and number of distinct editors. Is it just me, or is some of the mathematics and statistical techniques a bit off?  --LambiamTalk 14:05, 26 March 2007 (UTC)

Welcome template for mathematics

The recent welcoming of a new mathematics editor led me to wonder, what would be most helpful to tell a newbie to our mathematics community? Information could go in a new mathematics-welcome template, or on the project page, or both. So, aside from the usual Wikipedia welcome, what might we say?

In particular, what did you find most helpful? Most difficult to discover? What do you find yourself wishing most new editors would do or avoid doing with regard to mathematics articles (that we can teach)? Other comments?

To lead off:

  • In the difficult discovery category, I would hate to go back to life without popups (with popupRevertSummaryPrompt=true); the ability to hover over a linked technical term and see its lead paragraph is an incredible timesaver.
  • The Help:Formula page is essential, showing the parts of TeX supported by the MediaWiki texvc software. I also found it handy to have my own page of characters; but newbies need help configuring their system to display them all.
  • We should continue to expand the reference resources page; I'd love to see a wiki version of a BibTeX-style database across mathematics articles (perhaps bot-assisted).
  • Newbies often need illustration assistance; we could be more helpful than Wikipedia:How to create graphs for Wikipedia articles. (A recurring example: commutative diagrams.)
  • Beyond WP:MSM, I have suggested some writing tips that I wish were more widely followed.

Our target audience will include a gamut from professional mathematicians to young students; each needs to be told different things (for the former, Wikipedia is not a technical journal; for the latter, there is more to mathematics than you have seen). A good orientation could bring rich rewards. --KSmrqT 06:22, 17 March 2007 (UTC)

This sounds a great idea. --Salix alba (talk) 09:07, 17 March 2007 (UTC)
I am in complete agreement. If I had to choose a list of resources that took me a while to find, those that would have been helpful from the start, I would have listed exactly the resouces KSmrq has proposed above. VectorPosse 10:02, 17 March 2007 (UTC)
One more quick note. I might recommend that the math welcome be constructed in such a way that it supplement the normal welcome template instead of replacing it. (Actually, this is probably what KSmrq already has in mind.) It is likely that the math-specific editors we're targeting will have already received the standard welcome. Besides, the regular welcome has important general Wikipedia info that is indispensable. VectorPosse 10:08, 17 March 2007 (UTC)
I would suggest making a subpage of WP:WPM with resources for new editors, and then making the talk page message a welcome with a pointer to the subpage. Then we could also link to the subpage from WP:WPM and refer to it ourselves as a resource. CMummert · talk 18:28, 17 March 2007 (UTC)
I'd call it something like "Editor resources for mathematics articles", without the word "new", since they are also useful to seasoned editors. As far as I'm concerned KSmrq's buried essay, with a bit more structuring and emphasis on an editor's problems when writing a mathematics article, can be made into one of these resources.  --LambiamTalk 19:56, 17 March 2007 (UTC)
So anybody actually willing to create it? :) Oleg Alexandrov (talk) 03:37, 18 March 2007 (UTC)
Yes, I will begin soon if no one beats me to it.
Some questions:
  1. Are we agreed to accumulate the resources on a subpage of the project, and to make our template a minimal augmentation of the standard welcome template?
  2. Any other must-have items?
  3. Perhaps we should use the "Resources" subpage for this, moving its current contents to "Reference resources".
  4. Apropos of which, can our bot-master whip up something to go through the mathematics pages and collect all the references, so that we can begin to massage them into a coherent database? Lazily, I envision beginning with a simple accumulation of exactly what appears in each article, then sorting like entries together, then eliminating duplicates and converting each entry to a standard form, then filling in missing information like ISBN-13, then checking each entry and marking it as confirmed correct (with respect to the data in the entry, without regard to the use of the citation), then taking over the world. This is obviously a naive strategy that may be overwhelmed by size, but it is otherwise easy and incremental. Or perhaps something better already exists of which I am unaware? Or is the consensus that this is a crazy idea that only a fool would undertake?
Continuing suggestions still welcome, of course! --KSmrqT 09:20, 19 March 2007 (UTC)
I will start a thread below on the fourth bullet; it wouldn't fit here. CMummert · talk 12:13, 19 March 2007 (UTC)
One thing to point to is Wikipedia:WikiProject Mathematics/Participants. Not everyone finds their way there. For example CMummert — unaware or just shy? Paul August 05:21, 19 March 2007 (UTC)

One was created a couple months ago: User:C S/welcome. I didn't like it much though, which is why I haven't really used it. Perhaps having something concrete to critique will help. --C S (Talk) 05:40, 19 March 2007 (UTC)

I put something online at Wikipedia:WikiProject Mathematics/Editor resources. Everyone should feel free to add or remove things or criticize what is there. CMummert · talk 13:00, 19 March 2007 (UTC)

Extracting references from articles

Extracting references from articles is not trivial. It would be relatively easy to get a list of all the instances of {{cite book}} and friends. It would be much harder to automatically deal with hand-formatted references. I could get the contents of every "References" section (there are about 4500 of them), but it would take a lot of massaging. I'm not sure what plan you have in mind for the information. But anyway, I started the program to update my cache of math articles, which is going to take about 12 hours. I can extract whatever data is requested. CMummert · talk 12:13, 19 March 2007 (UTC)

Interest?

A while back I started writing Wikipedia:WikiProject Mathematics/Editor resources. Is there still interest in this sort of page? It would not be difficult to write Template:maths welcome to point to it. CMummert · talk 11:35, 29 March 2007 (UTC)

Ah, I was looking for that page the day before yesterday but I forgot why I was looking for it before I had found it. The "Editor resources" is very useful to point editors to. I hardly use welcome template myself (information overload) so I'm not really interested in that. -- Jitse Niesen (talk) 12:40, 29 March 2007 (UTC)
Although WP:WPM has an info box mentioning "Editor Resources", it does not link to WP:WPMER.  --LambiamTalk 14:11, 29 March 2007 (UTC)

Citizendium content

Citizendium is now live, and I thought I'd spend a few moments looking at their mathematics.

[21] is an article about Kummer surfaces, and is more detailed than what we say by quite some way. It is marked GFDL, so let's assume there is no problem in principle if we wanted to import it.

The problem in practice is that one wants to import the wikified content, but to 'edit' (get the marked-up version) one needs an account, and there are procedures for that (real name, CV, etc.). My question is: does anyone in this WikiProject already have an account? Would anyone actually want to create an account for the purposes of importing material here? Charles Matthews 20:49, 26 March 2007 (UTC)

http://en.citizendium.org/wiki/User:Oleg_Alexandrov --Pjacobi 21:16, 26 March 2007 (UTC)
http://en.citizendium.org/wiki/User:Mark_Jason_Dominus --Dominus 22:54, 26 March 2007 (UTC)
Caution. I can't tell what the copyright status of that article is; the notice at the bottom is not clear about how to determine it. It might be better to wait until CZ gets their act together before we start copying from them. I think I have seen comment by Sanger where he suggests that their "to be determined" license may be incompatible with GFDL, and it would be a pain to revert articles because of "contamination". There are some active discussions about licensing at the CZ forums. CMummert · talk 21:22, 26 March 2007 (UTC)
I agree with CMummert. Let's wait with the copying of material. —METS501 (talk) 21:24, 26 March 2007 (UTC)
Here is a quote from the CZ forum that reinforces what I was saying: "We should not underestimate the potential ills resulting from WP's ability to take CZ content." [22] I don't know that such opinions are representative, but the quote points out the need for caution. CMummert · talk 21:28, 26 March 2007 (UTC)
The current position at Citizendium is summed up by "We are definitely undecided (about the license)". They'll use GFDL for articles derived from Wikipedia, and either cc-by-sa or cc-by-nc for home-grown articles. These are Creative Commons licenses; cc-by-sa is similar to GFDL and would probably allow us to copy their articles; cc-by-nc differs in not allowing commercial redistribution, and thus that would prohibit copying their articles. So, yes, we better wait with copying their stuff. By the way, I also have an account there. -- Jitse Niesen (talk) 00:56, 27 March 2007 (UTC)

Is it OK to link to their articles from ours as we might with MathWorld? JRSpriggs 07:16, 27 March 2007 (UTC)

Personally, I can't see why we can't link to them as a reference or external link. CMummert · talk 12:14, 27 March 2007 (UTC)
Certainly we can link. I have no objection if this new source is treated as just another web site, but perhaps we should allow them to establish credibility before we genuflect. Consider MathWorld, one of the early sources for broad mathematical information on the Web; we have learned over time to be cautious in relying on content there. --KSmrqT 14:25, 27 March 2007 (UTC)
Yeah, let's hope that their licence won't be incompatible with GFDL. I assumed that they wanted to differentiate themselves by having a "better"/different way of doing collaborative editing than Wikipedia, such an attempt is of course laudable, whether it turns out to work or not. Making content transfer a one-way street however, would make it harder to decide later whether they were successful because they had a better model or because they were able to take advantage of Wikipedia content without giving anything back. Oleg Alexandrov (talk) 15:15, 27 March 2007 (UTC)
I don't quite follow. How can they use WP content and then license it under an incompatible license? Doesn't GFDL forbid that? --Trovatore 15:20, 27 March 2007 (UTC)
They can't; it's the material that originates at CZ that they haven't decided how to license. They decided a while back not to take everything from WP, but only take articles when someone will immediately edit them. Some editors will just start from scratch. CZ has a way of marking which articles contain WP content, but I don't know that it's very accurate yet.
This is all a matter of copyright, not intellectual priority. If a CZ article covers something that the corresponding WP article doesn't, we are free to write our own material about it so long as ours is sufficiently different than theirs, regardless of copyright. This is no different than the situation with Brittanica, which has no sort of open copyright. So I find the idea that a closed license will prevent us from using their material to be misleading. CMummert · talk 15:45, 27 March 2007 (UTC)
Heh. It is much easier to write an article by doing a copy and paste from somewhere and going from there, then starting from scratch, even with good references. So I'd think it does matter if their license is compatible with GFDL. Now, the people at Citizendum seem concerned that free sharing would be more advantageous to Wikipedia than to them. I'd doubt that. For example, we've been borrowing a lot from Planetmath, and they copy stuff from us sometimes too, and that benefited both sides and disadvantaged nobody. Anyway, it will be fun to see if Citizendium turns out successful. Oleg Alexandrov (talk) 03:06, 28 March 2007 (UTC)

Work on probability theory

I have added a Classification section to the probability theory, your comments/updates on it will be useful. To me it also seems that major portion of the article needs extensive copy editing... I am gonna propose this as a candidate for collaboration of the week. Cheers --Hirak 99 15:59, 28 March 2007 (UTC)

hm, would most probabilitists agree that one can "classify" in this way? seems kinda unlikely. i would recommend folks take a look. Mct mht 19:49, 28 March 2007 (UTC)

Geometric Median

I've created an article on Geometric median, please feel free to improve by adding more information in your free time. Is there a formal way to request for a diagram? Cheers --Hirak 99 16:03, 28 March 2007 (UTC)

It's not formal, but you could leave a request on Wikipedia talk:WikiProject Mathematics/Graphics. By the way, if geometric median is unique, and 1-dimensional median is a special case, then it is also unique, quod non. Same problem in higher dimensions for a set of collinear points of even cardinality, with the empty point set as an obvious case.  --LambiamTalk 08:02, 29 March 2007 (UTC)
Thanks, updated the uniqueness portion in the article. --Hirak 99 10:17, 29 March 2007 (UTC)

Corollary

I noticed recently that corollary is a redirect page to theorem. I thought someone here might want to make a proper article out of it.--Jersey Devil 01:15, 29 March 2007 (UTC)

  • It could be an attempt at humour, similar to the tired old joke of making Self-reference redirect to itself. Terry 02:04, 29 March 2007 (UTC)

I cleaned up Theorem a little a long time ago. The main difficulty is finding any sort of canonical reference for the terminology, in order to get the articles to be more than dictdefs.

Personally, I think it would be useful to make a single article "Theorem, Lemma, and Corollary" that discusses these terms. It would also be nice to do something with Mathematical terminology. But then, a lot of things would be nice.

Here is a quick summary of the various articles on mathematical terminology:

CMummert · talk 02:13, 29 March 2007 (UTC)

Mathematics now a featured article candidate

Mathematics has been made a featured article candidate.  --LambiamTalk 07:37, 29 March 2007 (UTC)

Disambiguation for M23, M24, and a few other numbers

A couple of Mathieu groups are listed on a few disambiguation pages that I have edited or will edit soon (e.g. M23, M24). The description of these number given at Mathieu group is incomprehensible to the average person. (Note that I have a Ph.D. in astronomy.) Could someone leave a short (one sentence) description of what these numbers are supposed to be on my talk page so that I can write reasonable entries for these numbers on the disambiguation pages? Thank you, Dr. Submillimeter 10:50, 30 March 2007 (UTC)

The description given at Mathieu group might not have much meaning if you do not know what a group is, but it pretty clearly says that M23, etc. are groups, and doesn't at all suggest that they are numbers. The entry already at M24 seems fairly reasonable to me - a disambiguation page is not the place to have long explanations. It could be reworded to "M24, a Mathieu group (a type of mathematical object)" or something like that. JPD (talk) 11:07, 30 March 2007 (UTC)
Thank you. I will try working with this, although something in even simpler terms would be better. Also, is it possible to write an introductory paragraph to Mathieu group that explains the concept in less technical terms? Dr. Submillimeter 11:28, 30 March 2007 (UTC)
It might be worth trying to get a less technical introduction in the article, but I'm not sure what you mean by simpler terms for the disambiguation. "M24, a Mathieu group"/"the Mathieu group M24" simply tells you its name(s) and provides the link, and "mathematical object" is the simplest way to describe what sort of thing it is. Anything more would either be more technical or would become the sort of long explanation that doesn't belong on a disambiguation page. JPD (talk) 11:43, 30 March 2007 (UTC)
What you have suggested may be the best that can be done for disambiguation pages. It would just be nice for the average reader to understand what it is if they come across the disambiguation pages. That may not be possible, so just "M24, a type of mathematical object called a Mathieu group" may be the only realistic solution. (I hope I have not caused any offense.) Dr. Submillimeter 12:14, 30 March 2007 (UTC)
I had a go at writing a standard dab for the five Mathieu groups. Geometry guy 15:02, 30 March 2007 (UTC)
I made some minor stylistic changes (removing parentheses and periods), but I will otherwise use Geometry guy's dab text. Thank you, Dr. Submillimeter 15:09, 30 March 2007 (UTC)
Yes, that's much better, but it's not going to be possible to give people an idea of what they are unless they already know some group theory, any more than a dab page should explain what a lenticular galaxy or Taoiseach is. JPD (talk) 15:26, 30 March 2007 (UTC)
But hopefully they would be defined sufficiently precise to disambiguate them from other entities sharing a moniker with lenticular galaxies and the Taoiseach. And it is really not much effort to write: [can refer to:] "the Taoiseach, the leader of the Irish cabinet". It may save the reader a click, because that may be just all they needed to know.  --LambiamTalk 13:54, 31 March 2007 (UTC)
I would consider reorganising the first and second paragraphs. To a layman the most interesting thing about them is that they are some of the exceptional cases in the classification of finite simple groups. Once the motivation for why these are objects worth study the reader might be encouraged the to read the more technical details. --Salix alba (talk) 20:21, 31 March 2007 (UTC)

Addition to the math style manual

Well, I see good agreements above that something needs to be said in the math style manual about this issue. I started a section, Wikipedia:Manual of Style (mathematics)#Choice of fonts. It is just an initial write-up, which I hope reflects the sentiment above. Changes to it and comments here on it are very welcome. Oleg Alexandrov (talk) 15:20, 24 March 2007 (UTC)

There is a certain amount of overlap with the subsubsection Font formatting, which is a bit confused as to whether it is about markup or about typesetting conventions.  --LambiamTalk 18:37, 24 March 2007 (UTC)

Italic Greek letters

The principal discussions of this have been whether to use italics on Greek names; for example in the article Constantinople. There has been agreement not to do that, because

  • the Greek text already stands out from running Roman text,
  • our Greek italic font isn't very good, and the bold Greek is worse.

I'm not sure how much this should apply to mathematics; but I see no reason to use α (''α''), when α works fine. Septentrionalis PMAnderson 15:39, 24 March 2007 (UTC)

This is another place where I would like to see flexibility and not policy. Any guidance on the use of fonts for Greek names simply does not apply to mathematics, any more than the use of Roman letters for Roman names implies mathematical variables should be in Roman. I actually think the italic Greek letters look better for variables and they more closely resemble the TeX form (for similar reasons, I tend to use \varphi and \varepsilon rather than \phi and \epsilon in TeX - but \theta rather than \vartheta). Also I sometimes find it helpful to distinguish π (a number celebrated on 14th March in the US and 22nd July in the UK :-) ) from π (e.g., a bundle projection in geometry and topology). Geometry guy 18:48, 24 March 2007 (UTC)
To my surprise, I discovered that the current Manual of Style is rather prescriptive on this point. I searched for some previous discussions, but found nothing. So for the moment, I will edit the MoS to make it less emphatic (excuse the pun). If someone wants to continue this discussion in a new section, I will be happy to contribute! Geometry guy 18:37, 30 March 2007 (UTC)

Apr 2007

This is the archive file "Wikipedia talk:WikiProject Mathematics/Archive 24". It is for April 2007.


Upright d in math notation

An anon has been going through articles replacing italic d with upright d in math articles, for example

\frac{d f}{d x}

to

\frac{{\mathrm d} f}{{\mathrm d} x}.

There is a small discussion about this at talk:Derivative.

As pointed out by Geometry guy, the previous discussion about this at Wikipedia talk:WikiProject Mathematics/Archive 4#straight or italic d? did not achieve consensus on what to use.

However, I would argue that while people should be allowed to use whatever notation they choose, I believe it is not a good idea to do mass changes to articles which used one type of notation for a long time.

That is to say, the vast majority of Wikipedia articles (all articles that I am aware of) use italic d notation. I vote to revert the anon conversions and to go back to status quo italic d notation at derivative and differential form. And if somebody starts a new article, and want to use roman d, they should be allowed. Comments? Oleg Alexandrov (talk) 15:00, 23 March 2007 (UTC)

I agree. Paul August 15:40, 23 March 2007 (UTC)
As do I. (Of course, I also think that the non-italicized d is wrong, but that's another story.) there are a lot of areas in mathematics where there are variations in notational style, and it seems a lot of energy gets spent on discussions about which one is right. However, within a single article, I think we should try to be consistent, if possible. Greg Woodhouse 15:46, 23 March 2007 (UTC)
The archived discussion on d vs. d is not so good, but there was a really intense argument over i vs. i for the imaginary unit linked there. I will paste their summary of the resulting accord:
Summary of reasons
Reasons for pro italic usage of imaginary unit in Wikipedia: i
most mathematics books/papers use italic notation of imag. unit
italic notation of imag. unit looks better Oleg Alexandrov
is a conceptual case of definition, italic i is needed Septentrionalis
Reasons for pro non-italic usage of imaginary unit in Wikipedia: i
Better semantics. This has several beneficial implications. PizzaMargherita
prevents confusion with running index i, electr. current, etc. Wurzel
offers electrical engineering technicians an imaginary unit notation which has no interference with neither (Maxwell's) current density j nor with electr. current i Wurzel
allows parallel usage with running indexes i,j Wurzel
improves readability of formulas containing the imag. unit i because of no overlapping definitions Wurzel
i is easily acessible on many computers/text systems / fonts Wurzel
Reasons for usage of \imath
Is an alternative offered by TeX Michael Hardy
Looks to me like the arguments for italics are: "it's convention" and "I like it" (the third one is not generally applicable). The arguments against are "better semantics" and numerous practical advantages, though anything mentioning current is irrelevant to mathematics and the one about being more accessible for many systems is irrelevant on Wikipedia. The decision was then made to keep i because it was the existing practice on Wikipedia, although there was no consensus.
Basically, italics won because we have a commitment to: (a) following widespread standards in the non-Wikipedia literature, and (b) when this is ambiguous, giving preference to existing standards on Wikipedia. Basically the same sorts of arguments work for d vs. d and the outcome is that the former is more common and the latter is better in every way except for being less convenient in LaTeX, so we stick with d since we already use it. I support the decision, though there's a good chance that one of these days I'll write something of my own when I'm in a mood to be pedantic and Romanize all my operators and symbolic constants, because that's how I am sometimes.
However, I think the single most influential reason people really hate these notational crusades is that everyone resents the use of a notation they don't personally endorse but they learn to tolerate it with a little rolling of the eyes, until someone rubs salt in the wound by unilaterally imposing their notation on Wikipedia. For this particular reason, I would say that even though we should use really clever, unambiguous notation as mathematicians, the use of this particular, slightly ambiguous notation has been suffered for decades if not centuries and we've learned to work around it. This can be done with a minimum of effort, such as paying attention to good choice of notation (which we should already be doing) and therefore the "practical advantages" of changing the italics to roman are pretty irrelevant, and far less than the practical disadvantages resulting from various bad feelings and revert wars that might ensue from doing so.
So I'd go further than agreeing to keep d. I would say that any time someone decides to make any sort of minor but widespread notational "improvements" they should be reverted with no more than a comment here to let people know what happened. The discussion itself is foregone and, as I've argued, more trouble than it's worth. Hell, by now it's standard practice :) Ryan Reich 16:07, 23 March 2007 (UTC)
Indeed. Both d and d are acceptable, both have advantages and disadvantages. We aren't going to ever have consensus to use just one of these, so we should follow Wikipedia:Manual_of_Style#National_varieties_of_English and allow the first major contributor to decide these style variants (which should then be consistent within each article). Changing all "d"'s to "d"'s in articles where one is not editing actively otherwise is like changing all instances of "colour" to "color" or vice versa, which is a blockable offense. Kusma (talk) 16:21, 23 March 2007 (UTC)

As an apology for causing trouble by partially supporting the anon, I promised to collect some links to previous discussions, to avoid (if possible) going over the same old ground. This is what I found so far: please add to this list if you find others. I tend to agree with User:Toby Bartels (although I am from the UK and he is from the US, we both personally prefer upright d's, but oppose the math project having a policy on this - see my comments after the list). Geometry guy 16:41, 23 March 2007 (UTC)

I am not convinced we need a policy on this. Has there been an edit war over this issue? Clearly if (as discussed before) one user makes 75 large edits in one day changing italic to roman or vice versa in many articles, these edits will be reverted and few will argue. I like diversity in wikipedia and such an edit damages this. However, sometimes a mass change in one article is not a bad thing and can increase diversity. I don't think it is a good thing if "the vast majority of Wikipedia articles... use italic d notation". Also, one of the great things about wikipedia is that it is dynamic. I don't like the idea of setting the original notation in stone, although there are of course cases where this is entirely justified, so that (for example) related articles evolve with similar notation. However, no one is going to get confused if one article with an italic d links to another with roman one, are they?
I, for one, frequently make minor edits of a repetetive nature when I contribute to an article: for instance I often italicize Greek letters in wiki-text so that they look more like their TeX counterparts. Am I right? There are pros and cons, but I would be sorry to see a policy on this, or to find my edits systematically reverted because the original contributor didn't use italic Greek letters.
As regards this particular issue, I sometimes replace an italic d by a roman d when it is clearly the exterior derivative (an operator) and not part of a "diphthong". I have no problem with another user reverting this, but I would not like it to happen systematically as a matter of policy. This is maths, not bureaucracy! In terms of the recent reverts, I would therefore like differential form to retain an upright d, and may one day give exterior derivative the same treatment. There is possibly a case for a policy for this particular usage, and I'm not sure it has been discussed separately before. Comments anyone?
I also think there is no harm in keeping the change to derivative, as this article needs a shake-up. Maybe the next editor who substantially improves this article should decide? If I were proposing a policy (and I'm not), that's the kind of suggestion I would make!
Finally, appearance (just so you know all the prejudices which inform my comments!): my view is that dx looks better as wiki-text, but for display math, the roman font renders so poorly that the case is not clear. Geometry guy 16:41, 23 March 2007 (UTC)
It is kind of unclear to me how notation change to dx from dx would cause a beneficial shake-up at derivative. Anyhow, I guess we all agree (including Geometry guy) that mass notation changes are not a good idea. And I do agree that officially codifying dx over dx or vise versa is not necessary. Oleg Alexandrov (talk) 02:56, 24 March 2007 (UTC)
Without falling into the loathsome practice of codifying, we could point out that (a) Wikipedia follows common conventions; (b) in mathematics (but not necessarily physics) italic d (and i and e) are the usual convention, at least for dy/dx and ∫y dx, in spite of ISO 31/XI and the recognized advantages of upright boldness; and (c) making mass changes of notation without discussion and consensus is not the way to go about it. The Manual of Style for mathematics already contains formulations like "Which method you choose is entirely up to you, but in order to keep with convention, we recommend ..." and "Either form is acceptable, but do not change one form to the other in other people's writing". I think that also here shedding some light on the issues for editors who are seeking guidance in this matter is only beneficial.  --LambiamTalk 09:38, 24 March 2007 (UTC)
Where did you see this in ISO 31/XI ? I only found this paper which states that, according to ISO 31/XI, the operator of differentiation should be set in roman type (as well as constants, i and e). pom 11:39, 24 March 2007 (UTC)
I didn't mean to suggest anything different.  --LambiamTalk 14:34, 24 March 2007 (UTC)
A non-mathematician's take. This has some similarities to the discussions of changing standard English spelling ('thru' for 'through' etc.). Let's face it: Convention matters, in life, dictionaries, grammar, & on Wiki. The law is made up of such conventions (driving on one side of the road, rather the other in a given country, etc.). What matters is not necessarily what convention is selected but that there is a convention for reaching agreement, so that expectations are satisfied, reducing the cost of communication. Of course conventions can change, which Wiki can reflect as necessary. So far as the math community is concerned, it would be misleading to portray notation that is non-standard as standard, which is what one expects in an encyclopedia, akin to no original research. But I like the flexibility shown above by the conventionalists in existing vs. new articles. --Thomasmeeks 12:46, 24 March 2007 (UTC)
Conventions operate in a context. What is convenient and clear in one context may be awkward and confusing in another. We are flexible with mathematical notation because we must be. As mentioned above, I have previously posted at length detailing a wide assortment of mathematical contexts for dx and friends. If, as I perceive it, we do have a consensus against any mass conversion or "standardization" compaign, then: (1) we may wish to put a note on our conventions page, and (2) revert without debate and leave a note on the editor's talk page informing them of said consensus.
I need to ask about two other notations mentioned, italic Greek letters and the square root of −1.
  1. Long ago (in wiki time) I saw an admonition somewhere to not italicize Greek variables inline, or so I remember. Thus I have used, say, "θ" (&theta;) instead of "θ" (''&theta;''). Maybe it was an issue of font availability, maybe times have changed, or maybe I remember wrong. What say ye?
  2. Perhaps because of long exposure to quaternions and Clifford algebras and the like, I use upright bold for our little friend i, and when only a few instances exist in an article I may inflict my preference on existing material. (See Cayley transform, for example, which I recently gave a major facelift.) I have been unaware of any consensus, and strongly prefer the bold convention for most things I create. However, in topics of complex analysis, say, it could be a serious pain to use anything other than TeX's default italic, and I would not dream of changing or complaining about i there. Except, as a matter of reader friendliness, I do object to using i as both an index and a special constant. Never would I use upright "i" without boldface. Any strong feelings?
As always, I see our role as being a bridge between a diversity of common mathematical practice and the needs of our readers, while making editing less onerous. In that regard, I note that despite our thousands of mathematics pages, the developers have not yet switched to blahtex instead of texvc, not for its much broader TeX compliance in producing PNGs, and certainly not for MathML output. I suppose I have been biding my time until the STIX fonts release (currently anticipated for April), but come that day I would like us to begin serious lobbying. To produce attractive, consistent mathematics notation by using <math> markup everywhere — that would be a great benefit for editors and readers alike. --KSmrqT 15:26, 24 March 2007 (UTC)
I agree with KSmrq. Imposing even a "usual" usage for imaginary units is even worse that doing it for d, since it affects a much broader range of contexts. In some contexts it is entirely familiar to use i for the square root of -1, even when it is simultaneously an index. In other contexts, much greater clarity is obtained by using a different notation, and there are plenty of options: i, i, i, \imath, \boldsymbol i and \mathrm i\, being a few that I have seen. Geometry guy 19:15, 24 March 2007 (UTC)
It is generally the best idea to use the italics one when dealing with the imaginary unit because that is the way most textbooks do it. It is the same with the ƒ(x) vs. f(x) argument, most textbooks use italics for it. The engineering books I've seen have all used non-italics for their variables so we can either: switch all the 'i's in the context of imaginary units to italics and all the ones representing resistance with regular face 'i's; or just use an italic 'i' as the standard, unless it would cause confusion in context with electrical engineering. The Roc 1217 21:43, 2 April 2007 (UTC)

Wikipedia:Mathematics Collaboration of the Week

Wikipedia:Mathematics Collaboration of the Week has just been marked as inactive, its not received much activity since November. Should anything be done to revive the collaboration? --Salix alba (talk) 07:34, 28 March 2007 (UTC)

The knack would be to nominate things people actually want to work on ... this idea has not ever really got off the ground. It's not really adequate to say "I decide, you write, that's what I mean by collaboration". On the whole a more elitist approach might be more welcome. (I mean it might work better, not that it is more desirable.) Charles Matthews 19:16, 30 March 2007 (UTC)
I agree. I also have another suggestion. I think it would be more productive to place the emphasis on producing A-class articles rather than FA-standard. I realise the distinction is slight, but it seems that FAC can be a rather dispiriting and bureaucratic experience of dotting every i and crossing every t in the definition of a "perfect wikipedia article" (it will be interesting to see what happens to mathematics), not to mention adding inline citations for everything, which do more to damage the readability of an article than enhance its authority. Instead with A-class, WikiProject Mathematics sets the standard and places the goals, and we can enthusiastically concentrate on the things we really care about in a mathematics article: its readability, liveliness, accessibility, depth and breadth and interest of its mathematical content. I also think that the number of A-class articles is an excellent way to judge the project's success. Geometry guy 11:11, 31 March 2007 (UTC)
I don't know whether it can be (re)vived, but if it can, it needs someone who is on top of this to coordinate the process, and it would help if that coordinator is one of our several well-known and respected contributors. As far as I'm concerned the coordinated effort could also be to raise the quality of a painfully embarrassing article to above the embarrassment threshold, or in general anything, as long as there is a potential and promise of a real improvement. Personally I'd really like to see the "entry level" articles improved, the ones must likely to be consulted by mathematically relatively unsophisticated readers, but others may be more inspired by advanced topics. A crucial aspect is the process by which each time the next "Collaboration of the



We have had a workaround for the nesting, using a <span> around the inner script. But if Jitse is right, the errors have been in the source the whole time, silently corrected. --KSmrqT 06:39, 9 April 2007 (UTC)
Should we ask a bot owner to list pages with <sub>...<sub> or <sup>...<sup> that were previously automagically repaired, so that we can fix problems now no longer covered-up?  --LambiamTalk 07:20, 9 April 2007 (UTC)

I think that Jitse is correct. The errors have been there all along, but were hidden by bugs in the processing of html. Notice also that where previously tags terminated automatically at the end of a paragraph, now they do not. A user had trouble with the "small" tag on the signature of Signpost not terminating any more and affecting the rest of his user talk page. JRSpriggs 11:11, 9 April 2007 (UTC)

Yes, I agree. I often make the mistake of missing out the slash in a closing sup or sub, but was previously forgiven by the generous HTML tidying code. Now it is not so generous, we should all go back to articles we have edited and check them for mistakes! I made this mistake several weeks ago at affine connection for example, but only discovered and fixed it today. Geometry guy 16:50, 9 April 2007 (UTC)
I can recommend the editor wikEd, which helps saving time by inserting sup and sub and much more. For those (like me) who do not crave for the command line text editor atmosphere, this nice tool creates some comfortable editing environment. Jakob.scholbach 17:37, 9 April 2007 (UTC)

Tidying up after the change to HTML Tidy

I'm going to do a database dump search and find all instances of <sup>......<sup>, <sub>......<sub>, <sup>......</sub>, and <sub>......</sup>. Note that some of these might actually not be problems (like if the user intended xyz) but if they're listed by a bot then we can go through them and check. —METS501 (talk) 17:59, 9 April 2007 (UTC)
For completeness, include <sup>...<sub> and <sub>...<sup>.  --LambiamTalk 18:34, 9 April 2007 (UTC)
OK. I'm doing each case separate, because it's easier that way, and I'll include those two. It looks like it's very successful, almost all the articles it's catching have the problem, which is thousands and thousands of articles, unfortunately. I'll post when I'm done making the list. —METS501 (talk) 18:49, 9 April 2007 (UTC)
Also, the newest dump is 7 days old, so it's catching many that've already been fixed (it caught the versions before these edits, for example) so I'm going to have to parse the live versions of pages before presenting the list. —METS501 (talk) 18:52, 9 April 2007 (UTC)
What a hero METS501 is! Things like this are what make WP so great! Geometry guy 18:59, 9 April 2007 (UTC)
LOL. First set of data done at User:Mets501/Pages that need to be fixed. —METS501 (talk) 19:31, 9 April 2007 (UTC)
OK, two sets done; that's about 900 pages to work with so far. I'm supposed to be on Wikibreak now, so I can't spend any more time, but that should be enough for the time being. —METS501 (talk) 19:48, 9 April 2007 (UTC)

Since I see that a lot of the subscript problems involve chemical formulae, I left a note over on Wikipedia talk:WikiProject Chemistry describing the problem and pointing to Mets501's page. Perhaps some of the people there can help as well. —David Eppstein 20:23, 9 April 2007 (UTC)

Perhaps we should make a separate list of problematic maths articles (the intersection of the list produced by METS501 and the list of mathematics articles).  --LambiamTalk 20:28, 9 April 2007 (UTC)
I fixed a very small handful of /sup errors (often mine) in mathematical articles. It would be good to update this problem from time to time, even if it requires us to drag the magnificent user Mets501 out of wikibreak. Geometry guy 20:47, 9 April 2007 (UTC)
I've updated the list. I can do this once or twice a day if that's the kind of update that you mean. —METS501 (talk) 21:43, 9 April 2007 (UTC)
Wow, fantastic! Once a day (or every few days) would suit me fine! Lets hope the chemists can sort out their stall too. Geometry guy 21:54, 9 April 2007 (UTC)
OK, I've rewritten the program, so all I have to do is press one button and the bot updates the list :-) I can run it often, because it's no work for me! [26]METS501 (talk) 22:12, 9 April 2007 (UTC)
Good work so far. Some questions: Does the consolidated list include all combinations of subscript and superscript? Can we have a consolidated list intersected with mathematics articles to let the chemists fend for themselves? How do I prevent an article with properly nested script tags (x<sup>y<sup>z</sup></sup>) from being listed every time? The numbers do not seem to indicate the number of errors; can that be changed? Can we get a display of a little text surrounding each error, so we don't have to search through twenty tags to find one? --KSmrqT 23:21, 9 April 2007 (UTC)
Thanks. Unfortunately, I have very little time now; not nearly enough to invest in writing code much more complex than it is now. It looks like the list is being weeded through quite fast now by Beetstra with AWB, and the rest we'll have to be done by hand. I'll look into putting in some surrounding text, but I'm not sure how quick it would be do that. If you remove a page from the list, the bot won't add it back, so if it's on the list in error, just remove it. The bot has two functions (at the moment): it can go through the database and check for <sup>...<sup> and <sub>....<sub>, and it can go through each page listed at User:Mets501/Pages that need to be fixed and check if it still has a syntax error. I'm going to expand the first function soon to include other syntax errors as listed above. —METS501 (talk) 00:10, 10 April 2007 (UTC)


Citizendium content

Just to bring back an old discussion about content from Citizendium, the Special:Export page works on Citizendium to get the wikicode of any page. For example, to get the code of their Mathematics page, visit http://en.citizendium.org/wiki/Special:Export/Mathematics. Not in ideal form, but it's a way. —METS501 (talk) 00:01, 10 April 2007 (UTC)

The copyright of these pages is, unfortunately, still unclear. It would be prudent to avoid copying material from CZ to here until CZ gets their act together. CMummert · talk 00:52, 10 April 2007 (UTC)
Definitely. I was just pointing out that we actually don't need registered users there to get their source code. —METS501 (talk) 03:11, 10 April 2007 (UTC)

Institute for Mathematics and its Applications

In one of the most idiotic edits I've seen in a long time, User:The Kinslayer, who seems to spend most of his efforts on topics of no importance, marked Institute for Mathematics and its Applications for speedy deletion on the grounds that it is not important, and did not notify anyone who had edited that page. It was recreated recently. Someone else then deleted it. Michael Hardy 02:40, 29 March 2007 (UTC)

This user seems to have a problem with articles on institutes.[27][28][29]  --LambiamTalk 07:03, 29 March 2007 (UTC)
This user is not alone. I wrote a stub on Fachinformationszentrum Karlsruhe which got marked for speedy deletion by Realkyhick the next minute. Now that's itchy fingers. Jmath666 07:47, 29 March 2007 (UTC)
It is an unfortunate consequence of the large number of nonsense pages created each day that, when creating a stub on a person, company, institute, etc., one must immediately add references to assert notability or the article is likely to be tagged for deletion almost immediately. The number of math related articles created each day is far less than the number of nonsense or non-notable pages, so we can't really hope for some sort of special treatment. One solution is to write such articles in a subpage of your user page and move them into place once they are basically done, even though this violates the basic idea of collaboration on the wiki. CMummert · talk 11:27, 29 March 2007 (UTC)
Sounds like these human spam filters need their Bayesian statistics adjusted. The odd thing is, ever since I began bringing up random articles frequently, I've been struck by the fact that almost all are a paragraph or two on an obscure topic. So this "shoot first" approach, while an understandable reaction to garbage, is tainted by ignorance. A town of 300 people: no problem; a minor sports figure: no problem; a major mathematics institute: kill it. The garbage is a cancer, and these people want to feel useful. But, as so often happens, the "cure" has damaging side-effects, sometimes worse than the disease. --KSmrqT 14:32, 29 March 2007 (UTC)
I recently exchanged a few pleasantries with Realkyhick about his shoot first and ask questions later approach to new articles. I notice that he's a member of the New Pages Patrol. He also ignores the guidelines for that process with some regularity. I suggested that he at least look at the page history before tagging an article with a speedy delete tag, but he doesn't seem inclined to accept that suggestion. Type A personality, I guess. DavidCBryant 15:22, 29 March 2007 (UTC)
Fachinformationszentrum Karlsruhe happens to be marginal (not a major mathematics institute like IMA) but the original article did indicate why it was notable, even if the article was very short. It took some speedy expansion (which I really did not plan on doing right at the time) to keep the trigger happy patroller off. Apparently it is not clear what it takes for an article to be a valid stub. Well, the lesson is just keep the red tags in and do not go the next step unless one is ready to invest some work right at the moment. Jmath666 15:41, 29 March 2007 (UTC)
It seems that the root of the the problems discussed here is that the speedy deletion is too speedy - both the tagging and the admin action. Per CSD: The word "speedy" in this context refers to the simple decision-making process, not the length of time since the article was created. There should be a reasonable time required for both. There is something vague about that in CSD but I could not find mention of some mandatory wait period anywhere. There should be one. Jmath666 23:14, 29 March 2007 (UTC)
There are, I think, good reasons for speedy deletions to be speedy. The problem is not the existence of speedy deletions, but rather someone abusing the speedy deletion process. The only criterion I can see in WP:CSD that might fit is A7, "does not assert the importance or significance of its subject". That is, even when you write a stub, you have to explain what is notable about the subject; why is it important enough to be in WP? E.g. in the current article "largest single mathematics grant the NSF has ever awarded" seems to be enough to counter that criterion. I don't know how to access the previous versions in order to tell whether similar language was present in the deleted versions, but if it was, they shouldn't have been deleted. I don't know what the process is when one feels that an admin has been consistently abusing speedy deletion, but I assume there is some appeal procedure available. —David Eppstein 23:52, 29 March 2007 (UTC)
I added that fact because I thought it was interesting, not really to establish notability. It was not present in previous version, which also had no references except the external link. I added the reference to the SIAM article to assert notability. WP:notability doesn't mean notability - it means "discussed in multiple, independent reliable sources", so the only way I see to assert notability is to include such sources.
As for appeal, you could I suppose go to WP:DRV, or you can ask a friendly admin to give you a copy of the deleted version, add some content, and recreate the article. There are about 20 admins associated with WP:WPM, which is about 1 per 800 articles, a better ratio than WP as a whole. CMummert · talk 00:35, 30 March 2007 (UTC)

You can't know what should be considered notable and what should not without familiarity with the field. It seems to me those who were involved in the present case disregarded that fact, which I would think would be obvious. Michael Hardy 00:00, 30 March 2007 (UTC)

Of course you can't tell what is notable and what is not without some knowledge, but it's not too hard to determine whether an article asserts notability (in this case, importance or significance), which is the speedy deletion criterion. Articles about even obviously notable subjects will get deleted if they do not include anything telling the reader what their importance is. The only thing that could possibly be interpreted as an assertion of significance in the original article was that the IMA was a body with academic aims associated with a particular university. That description does indeed suggest that the organisation could be quite significant and I wouldn't list it for deletion, but I can't really blame anyone for thinking there was no claim to importance. JPD (talk) 10:01, 30 March 2007 (UTC)
Now that the history has been restored, we can look at what was there before deletion. Two things strike me. One, behind the scenes, is that the article has a long history. Two, the article has a link to the organization's web site. It would take less than thirty seconds to check both of those, which should give more than enough information to see that a "speedy" tag was wrong. Note I am assuming a tagger and an admin who know nothing about the standing of the editors who touched the article, and who know nothing about the mathematics world. Was it a stubby, lackluster article? No doubt. Was "speedy" appropriate? No way.
Here's what the WP:SPEEDY page says, at the top:
  • Before nominating an article for speedy deletion, consider whether an article could be improved or reduced to a stub; speedy deletion is for cases where an article does not contain useful content. Note that some Wikipedians create articles in multiple saves, so try to avoid deleting a page too soon after its initial creation. Users nominating a page for speedy deletion should specify which criteria the page meets; it would also be considerate to notify the original author.
From this lead paragraph of three sentences, not one was properly followed. I frequently look at random articles, and the one that I just hit is HaShevet. Compare it, especially what it explicitly asserts (or fails to assert) about notability, with the IMA article at the time of tagging and deletion. So forget the CYA, which is not very convincing. The typical catastrophic failure involves a sequence of things going wrong; here, article, tagging, deletion, and response.
From Barlett's Familiar Quotations:
  • "Thus grief still treads upon the heels of pleasure;
    Married in haste, we may repent at leisure." — William Congreve, The Old Bachelor, Act V scene 1.
Sum the time spent by multiple editors in response to the hasty deletion and compare to the time necessary to do the right thing in the first place. Need I say more? --KSmrqT 17:28, 31 March 2007 (UTC)
Unfortunately this IMA article *did* look like a typical Speedy candidate when it was nominated. It said in effect, 'There is this institute at University of Minnesota, it exists, and it's wonderful'. Its only reference was its own web site, and it had no links to other WP articles except to the Univ. of Minnesota and another institute with a similar name. There was no mention of NSF or SIAM in the version nominated; certainly nothing about the largest NSF grant ever.
A mathematics editor described the tagging as vandalism; I think that was unfair. (See User_talk:The_Kinslayer#IMA and User_talk:Coredesat/Archive_7#IMA). Speedy deletion does not poll the universe to see if the deletion is wise, it just goes and does it. Such deletions are easily reversed if someone complains. The clue that the speedy-tagger missed was 'mathematics of the highest caliber'; I guess that should have registered as the claim for notability. I suggest that the phrase 'idiotic edits' (which sounds like a personal attack) be removed from the above comment. EdJohnston 01:19, 5 April 2007 (UTC)
I agree that there is an overreaction here. Vandalism is a serious charge, alleging more than just simple ignorance. I think it's best to put the best front possible when engaging people on their talk pages as a representative of a WikiProject. There is a problem of ignorance here though. It ought to be addressed in a forum for people like the new article and recent changes patrollers. A lot of these anti-cruft policies like CSD A7 were created for expediency in deleting non-notable people and groups. One thing failed to be understood by these people is that an institute at a major American research university is already far more notable by its affiliation than an institute in say, Elbonia, just like someone who wins an AMS prize is automatically far more notable than somebody who wins some Elbonian prize. (Or even a full professor at an American research university is probably already far more notable than a winner of said Elbonian prize, even though the latter may look more like an assertion of notability to the ignorant.)
where the heck's Elbonia and why we hatin' on the Elbonian folks? Mct mht 12:52, 11 April 2007 (UTC)
Elbonia is a very backward country (6th or 7th world) in the cartoon universe. :) JRSpriggs 08:11, 12 April 2007 (UTC)
In addition, a fact which may look like an assertion of notability to someone unfamiliar with the mathematical world may in fact be completely irrelevant to what makes a well-written, informative article; hence people used to writing good articles will not include such assertions. Rather than rail about this, it is more productive to let the patrolling community know. In fact, if you go to these pages, you will find they do have guidelines such as don't speedy an article too quickly after creation, don't be too hasty in prod'ing, etc. People who do a bad job of speedying articles are not representative of the best of the patrolling communities, and we should not declare all-out war on these people. Instead, let's work with them and straighten this out pleasantly, by say, discussion at Wikipedia:RC_patrol and Wikipedia:New_pages_patrol.
The real problem in this instance seems to be that the wording of CSD A7 ("An article about a real person, group of people, band, club, company, or web content that does not assert the importance or significance of its subject.") is problematic. In the past, I've had to argue with people that an article stating "This guy is really, really important. He lives on 3213 Wakefield Street, Ohio." does not assert notability. It seems that fewer people think of this as such an assertion nowadays, most having come to the realization that said assertion should satisfy a condition such as plausibility. Actually, it's funny, but at one point I'm certain CSD A7 said it should be "plausibly assert", now it doesn't! (Some of these points have been raised at Wikipedia_talk:Criteria_for_speedy_deletion#CSD_A7_again; I think it's a good idea to join this discussion quickly and make our views known in order to avoid this kind of situation in the future) --C S (Talk) 11:13, 11 April 2007 (UTC)

Proof sketch for Gödel's first incompleteness theorem

This article was created a few months ago and has sat mostly untouched for two months. As it stands, the article has problems visible from even a cursory reading. I was about to start working on it, but first I want to get a sense of whether this article belongs on WP at all. On the one hand this is a famous and important result that is covered in practically every text on mathematical logic. On the other hand, the proof can be found in practically every text on mathematical logic, so sketching the proof here only duplicates what is already available (and probably better) in other locations. CMummert · talk 22:42, 4 April 2007 (UTC)

Would it be much work to fix it up? It's kind of entertaining that the proof is here, and a person can jump into it and at least pretend that they understand it. Adding a list of books that explain the proof more thoroughly would certainly be useful as well. I see on the Talk page that you left some suggestions for the creator of the article, and he hasn't followed up. EdJohnston 22:57, 4 April 2007 (UTC)
It looks like a lot of work to me! For one thing, it is dangerously close to WP:OR. The use of three digit codons follows Hofstadter, but a different coding is used and is unsourced. It is also too technical, and the English is not great. At the moment, I find the proof sketch in the main article more helpful. In particular, I think it is better not to emphasise a particular choice of coding. Geometry guy 11:43, 5 April 2007 (UTC)
To fix this article would require a great deal of effort. The correct proof has some technical, subtle parts that take care to explain. I think the article is too vague, not too technical. For examples of problems in the current article, look at the paragraphs numbered 1, 6, and 7. CMummert · talk 11:53, 5 April 2007 (UTC)
I have seen this discussion only now, indeed English is not my first language, and I'll see what I can do regarding your comments. Anyway if the article is too vague for some and too technical for others, maybe that means that it's just in the corect level for others? no original research was done here, and the 3 digit codon I used is borrowed from the "Goedel Esher Bach" book though I used a different coding exactly because the choice is not important - surely you wouldn't call this WP:OR. There's also a link to the formal proof. Since this theorem atracts a lot of attention from people with only limited mathematical background, it seems to me nice that there's something they can read which would hopefully give them a clue about how the theorem is proven.Dan Gluck 19:51, 5 April 2007 (UTC)
Editors here will be uncomfortable if they don't think your article is correct. Do you have the background to fix the subtleties mentioned by CMummert? I suppose you could skip the hard parts if you left a pointer to a book that supplied the missing material. But then the fact that your coding is different might confuse people who had to switch to the book. EdJohnston 01:35, 6 April 2007 (UTC)
I thought the problem wasn't that it's incorrect, but that I skipped some technical parts. Since there's a pointer to the full proof on the web, and (I think) I mentioned all the places where I have done so, I don't see a problem. The proof on the web doesn't use a coding, since it does not need to specify one explicitly; the coding I have given is only an example for pedagogical purpose, as in Hofstadter's "Goedel Esher Bach" book. I would love to use the coding in that book, but I don't have it, and anyway I'm not sure it's permitted by copyright law.

Anyway perhaps I missed it, but all of CMummert's specific comments (in the article's talk page) are related to the form of the article - he suggests deviding it to sections, adding more links etc. I saw no content-related specific comment. Dan Gluck 19:54, 6 April 2007 (UTC) Anyway mathematical logic is not my field of expertise, so if it is yours, and you think the article is incorrect and cannot be repaired, feel free to erase it :( Dan Gluck 20:00, 6 April 2007 (UTC)

I added some comments on the article's talk page about the content. It's not the content of this particular article that led me to ask a question here; I am certain that this particular article can be fixed up, and i was about to do so myself. The real question is whether an article entirely devoted to a proof is acceptable. I didn't want to spend a while making changes only to have the article is nominated for deletion. Personally, the more I read this sketch the more I like it. CMummert · talk 20:16, 6 April 2007 (UTC)
I'm not a lawyer, but I believe it is legitimate to use Hofstadter's coding as long as his book is clearly cited (and this has to be done anyway to source the approach taken by the article). This would require some work, however, because Hofstadter's coding uses the successor function to define numbers, instead of the (rather nice) base 10 coding of the article. Perhaps a compromise coding would work better (although I still worry a bit about OR - unusually for me, since I think explaining things in new, interesting and engaging ways is exactly what an encyclopedia should do). Anyway, I have GEB and would be happy to contribute the relevant information. Geometry guy 15:58, 9 April 2007 (UTC)
Well, the criterion for OR is this WP:OR#What_is_excluded.3F. I don't think the article satisfies any of the conditions there. If everybody agrees that there are no mistakes, and it is a rephrasing of the proof (hopefully in a more understandable way) with some technicalities overlooked, I don't think it's OR. Dan Gluck 20:52, 12 April 2007 (UTC)


Redundant articles

Hi. I noticed when adding a link somewhere to Bijection that we have individual articles for Bijection, injective function and surjective function, as well as an article called Bijection, injection and surjection. Is this the optimal way to cover these topics? It seems redundant to me. At the least, should bijection be renamed to bijective function, for consistency? -GTBacchus(talk) 18:52, 9 April 2007 (UTC)

I think your suggestion to rename is spot on to make the titles at least parallel. I would say that the Bijection, injection and surjection is redundant, except it's actually very nicely written. For now, I've linked the three concepts in that article to their respective pages, and I've added some {{main}} templates in each section. I'm interested to hear other opinions on this. - grubber 19:04, 9 April 2007 (UTC)
A quick review of the talk pages shows that this has been discussed several times. I made some comments here. CMummert · talk 21:13, 9 April 2007 (UTC)
It appears that, while opinions differ on what to do with the joint article vis-a-vis the separate ones, there is at least a broad agreement that bijection should be moved to bijective function, for consistency with injective function and surjective function. I see that this point has been raised at Talk:Bijection#Rename?, but not much came of the discussion. I've commented there; perhaps it would be appropriate to do an "official" move request through WP:RM, or we could just agree to do it because it makes sense. -GTBacchus(talk) 21:27, 9 April 2007 (UTC)
I don't think that you will be able to do the move yourself, because of edit history at the redirect page (I'd be curious to know if you can, in fact). In any case there are quite a few admins in the math project, so you won't need to go to WP:RM to get this done. Let's wait a little while to give people a chance to object, though. CMummert · talk 21:42, 9 April 2007 (UTC)
(edit conflict) While opinions have differed in the past, perhaps it is time to revisit the idea. I can't imagine anything doing a search and lading on Bijection, injection and surjection. I agree, though, that the material there is good. Is there any reason this good stuff can't be moved to each of the three separate articles? VectorPosse 21:45, 9 April 2007 (UTC)
(reply to CMummert) I'm one of the admins who monitors WP:RM and moves pages daily, so that part's not a problem. The only reason I suggested going through RM is that it sets up a somewhat official discussion area, and that's often a good way to bring people with opinions out of the woodwork. It's no problem at all for me to set up a discussion, but at the same time, it's really not a formal necessity. -GTBacchus(talk) 21:48, 9 April 2007 (UTC)
Sorry about that - you weren't on my list of admins who contribute to the math project. I think that a formal process isn't warranted if there is clear consensus for the move. Renaming pages isn't supposed to be a big deal. I went through the page history of the destination and it has only ever been a redirect. CMummert · talk 22:06, 9 April 2007 (UTC)
No worries; most of my contributions here aren't math related. You're certainly welcome to contact me anytime you need an admin who's mathematics-literate. For this page, I think we'd be fine moving it after allowing a day or so for anybody to raise an objection. (It would probably be fine to do it right now, but it can't hurt to sleep on it.) Because I may not be online tomorrow, I've gone ahead and deleted all but the top redirect at bijective function, so now anyone can carry out the move. -GTBacchus(talk) 22:16, 9 April 2007 (UTC)
I think redundancy can be discussed, but I object to changing bijection, which is definitely used, although, perhaps, not as much as bijective map, to bijective function, which is very contrived sounding and not at all common. See my comments here. Arcfrk 04:02, 10 April 2007 (UTC)
Huh, now that you say that, I guess I have heard "bijective map" more than "bijective function". Should we be talking about moving the other two articles to injective map and surjective map? I think all three should be the same, and injection isn't available. -GTBacchus(talk) 04:48, 10 April 2007 (UTC)
I don't really care, because there will be redirects, but I think that "map" is a poor choice because it has too many real world meanings. "Function" is much more clear, and the bare word "Bijection" is pure jargon and thus unconfusing. CMummert · talk 00:45, 11 April 2007 (UTC)
I see nothing wrong with injection (mathematics) and surjection. Septentrionalis PMAnderson 23:42, 11 April 2007 (UTC)
Yeah, that mirrors common usage the best. -GTBacchus(talk) 23:44, 11 April 2007 (UTC)

A question about plagiarism

I recently ran across some copyright violations, and read the policy. I think I understand how to go about cleaning those up. This article is different. It's an outright copy of this newsletter article. Interestingly, there's no copyright notice on the isi web site – or at least, I couldn't find it. Also of interest, this article was contributed by User:Pdagum, who one might reasonably suppose to be a relative (son Paul?) of Prof. Dagum.

Anyway, I'm unsure what to do about this one. It's an "in memoriam" article, quoted verbatim. As such it certainly doesn't sound very encyclopedic. Suggestions? DavidCBryant 14:40, 12 April 2007 (UTC)

It sounds like a violation to me- copyright is assumed unless specifically released. So "no copyright notice" isn't good enough, we need a specific statement that it is free content. Staecker 14:48, 12 April 2007 (UTC)
I would remove the copyrighted text, leaving a stub, and leave an explanatory message for the article's creator. You could try {{uw-copyvio}} along with an explanation of the specific situation. CMummert · talk 14:56, 12 April 2007 (UTC)

Projective space - painting of Dürer

Does someone know the title of the painting by Albrecht Dürer (I guess, not absolutely sure though), which shows a projection a smaller shape onto a bigger canvas? I know, the description is very vague... The image has some geometrical interest, I'd like to put it to projective space (if it is available somewhere). Jakob.scholbach 04:51, 13 April 2007 (UTC)

The one most often used is this picture of a lute, from Dürer's Underweysung der Messung mit dem Zirkel und Richtscheyt, Nuremberg, 1525. However, another choice is the reclining nude from the same work. I would expect that an image scanned from the book is free of copyright restrictions, but that's a legal question, and the scans I have seen on the web are not ideal. --KSmrqT 07:41, 13 April 2007 (UTC)

Strange article

Any hope of evolving Mathematical landscape into something encyclopedic or shall it go straight to AfD? --Pjacobi 13:15, 8 April 2007 (UTC)

I think the point of the article is something called the "Mathematical landscape conjecture". The author of the article is new here, so maybe asking him/her for a reference is a good first step. CMummert · talk 14:14, 8 April 2007 (UTC)

Just saw this before coming here. Tagged several statements that seemed speculative and unsourced with {{cn}}. But if it doesn't improve, I'd likely vote Delete in an AfD. —David Eppstein 16:38, 8 April 2007 (UTC)

Strange indeed. Although there is a game some theoretical physicists play with speculating about why certain numbers appear, we can say things about any number. For example, 1728 (which is 123) is a very special number that is not listed. As written, this article is hardly more than numerology. --KSmrqT 21:21, 8 April 2007 (UTC)
I posted a message on User talk:Qloop. Let's see what the author has to say. -- Jitse Niesen (talk) 02:59, 9 April 2007 (UTC)
This one has been struggling me somewhat. Although it is not very far from my research area, I have not heard of the "mathematical landscape", and the "mathematical landscape conjecture" seems to be not only unsourced and very vague, but also complete nonsense. I tried to source this article myself, but the best I have found so far is one of John Baez's nice pages. I think I know what the article is trying to say (and there is something interesting to say here), but at present it is clearly in the AfD firing line, and is a magnet for a whole load of numerological speculation. For example, the "26 dimensions" section has already attracted the comment that there are also 26 sporadic groups, which is a completely unrelated fact (as far as I know from sources to date). Geometry guy 17:07, 9 April 2007 (UTC)
I've never heard it given the explicit name of "mathematical landscape conjecture", but I'll affirm that it is the defacto deeply held tenet held by those theoretical physicists who have wandered off to string theory and beyond. After the fantastic successes of General Relativity, Standard Model and QCD, and the near-misses of Kaluza-Klein theory, supersymmetry and etc., a large part of the theoretical physics community decided that surely, the Theory of Everything would be immediately obvious, if they just knew only a tiny little bit more math, or that, at least, if nothing else, they'd be the second person on the planet to figure it out after Ed Witten did. The near-miss of Monstrous Moonshine only affirmed this belief of the congruence of mathematical landmarks and physical reality: there was 3 or 6 or 12 months or so, in the mid-1980's, where a lot of physicists honestly, truly believed that the monster group really was the group that described the known universe and everything in it. A lot of ink was spilled. Well, here we are 20 years later, and we've got doodly-squat to show for it. The experimental physicists are all pissed off and are saying that the theoreticians are shirking their work and have abandoned them, and string theory is theological mumbo-jumbo. But the core belief remains: if we can only find that one magic mathematical expression, it will be everything, and of course it'll be a Lie group, and of course it'll be p-adic, and of course it will have a j-invariant, and a moduli space, and etc. woven into one beautiful whole. Why, in fact, the ratio of the strong/weak/electric/gravitational forces are in the same proportion as the first four Mersenne primes! Didn't know that? Well, there are string theory papers out on ArXiv that explore this numerology... linas 00:04, 10 April 2007 (UTC)
To be clear, I'd probably vote to delete this article, since it does seem to be OR. linas 00:30, 10 April 2007 (UTC)
Perhaps the article could be saved by changing the focus to the sociological phenomenon described by Linas in his message here. JRSpriggs 07:05, 10 April 2007 (UTC)

Call me a pessimist, but writing about this kind of sociological stuff is difficult and will no doubt be easily prey to OR, lack of citations, and just generally crap. We already have great difficulty with articles about mathematical education (which can be readily sourced and is written quite frequently about). Who's ready and qualified to change this article anyway? --C S (Talk) 11:59, 15 April 2007 (UTC)

Help the Physics Project

The level of activity at the physics project has fallen way off. See Wikipedia talk:WikiProject Physics#Is this WikiProject moribund?. If any of you have an interest in physics, but have not been paying attention to it lately, now would be a good time to get involved. JRSpriggs 07:15, 10 April 2007 (UTC)

I don't think emphasising high-profile departures is very helpful. Charles Matthews 12:10, 11 April 2007 (UTC)
I do not think that killing the messenger is very helpful. JRSpriggs 08:13, 12 April 2007 (UTC)
I wasn't intending to. I was commenting on the content of that discussion. Charles Matthews 11:44, 15 April 2007 (UTC)

Requested articles

Many of the requests currently listed on Articles requested for more than two years seem to be mathematical ones. The requests on this page are those which have been unfulfilled for the longest time, and we therefore tend to treat them with a higher priority than those requested only for one year and the other request pages. If any members of this WikiProject have sufficient knowledge and access to sources to write a good stub on one or more of these topics, it would be much appreciated. Thanks – Gurch 10:31, 11 April 2007 (UTC)

Those are almost all logic articles; more specifically set theory. Charles Matthews 12:54, 11 April 2007 (UTC)
All but one of the titles listed on Wikipedia:Articles requested for more than a year#Mathematics are also on the > 2-year list, and are moreover conveniently selected on being maths topics. (The extra title looks more like a physics topic to me.)  --LambiamTalk 15:16, 11 April 2007 (UTC)

Many of them can just be redirects. Take the topmost example from the 2 year list, amenable set, for instance. I was, just the other day, going to write an article on the Gödel, Jensen, Lévy etc. constructions (none of which exists as an obviously named article), but then I soon found that an article already exists on the constructible universe. It is pretty unlikely that we will be able to write a feature length article on amenable sets (without abandoning all pretence to being a general encyclopedia, that is), but we should certainly be able to do a better job of presenting the various independence results— if only to redirect key concepts to more comprehensive articles. Kaustuv Chaudhuri 16:50, 11 April 2007 (UTC)

These are lazy answers :) If e.g. amenable set should be a redirect then why not make a redirect rather than just chatting about it? But are we talking about admissible or amenable sets? The first is mentioned in constructible universe, the second is not. After an hour searching, I eventually found a reference discussing the distinction between admissible and amenable sets, but did not understand it. Surely we can do better than this :( Geometry guy 22:16, 13 April 2007 (UTC)
Cheer up geometry guy! I think I finally understood the difference between amenable sets and admissible sets, so I fixed that. I also redirected the redlinks that seem to have something to do with Determinacy to that article. Geometry guy 14:11, 14 April 2007 (UTC)
I'm glad you took some action, but I must say that the end result is not as perspicuous as one wishes. Someone will eventually have to sit down and write some text. I myself must continue to plead laziness for the time being. Kaustuv Chaudhuri 09:05, 16 April 2007 (UTC)

Category:Mathematicians by religion

At the moment, mathematicians are divided by religion in Category:Mathematicians by religion. Analogous categories for many other professions (including in many scientific fields) have generally been deleted, mainly because religion is largely irrelevant to the given profession. Some people have defended these categories as being used specifically for clergy or devoutly religious, but they are rarely used that way in practice, as the category names leave open the possibility that someone will use these categories to identify anyone who is a mathematician of a given religion.

I was wondering whether these categories had the support of WikiProject Mathematics or not. If people here generally disapprove of these categories, then I can nominate them for deletion. On the other hand, if people really want these categories, then I will leave them alone.

Could other people here please comment? Thank you, Dr. Submillimeter 15:28, 13 April 2007 (UTC)

I think this is an example of categorization gone astray. It is not that important what a religion a mathematician had. One's got to pick and choose which are the most relevant categories to add a person too, and I doubt this qualifies. Oleg Alexandrov (talk) 15:38, 13 April 2007 (UTC)
Classifying G. H. Hardy as an atheist is probably harmless; it is one of the few notable non-mathematical features of his character. Pity the article doesn't mention cricket. Extending this, even to Erdős or Russell, is very doubtful; and since the whole variety of category is normally a form of nationalism, bad for Wikipedia. Septentrionalis PMAnderson 16:39, 13 April 2007 (UTC)
This category certainly doesn't have my support: it looks like a case of overcategorization. However, there is a potential minefield with the subcategories here, and I wish Dr. Submillimeter good luck in finding a path through it. There is probably little problem with the deletion of the atheist, Buddhist and Christian subcategories, and it seems reasonable to keep Category:Pythagoreans. However, the other three subcategories are a bit more tricky...
Something similar is happening with Category:Women writers. If the overall category is legitimate, is it not legitimate to create intersection subcategories when the category becomes too large? In this project Category:Women mathematicians seems well accepted as is Category:Mathematicians by nationality (or geographical location) and its subcategories. I am not necessarily questioning the legitimacy of this, but where do we draw the line when it comes to closely related issues of ethnicity and religion? Geometry guy 19:04, 13 April 2007 (UTC)
Most other occupation by religion categories are about careers that involve religion (missionary work, religious leadership positions, philosophy, etc.). Some of the remaining inappropriate categories for Muslims (Category:Muslim astronomers) and Hindus (Category:Hindu physicians) are already nominated for deletion. I think some of the other occupation by ethnicity categories have also been deleted; I certainly have not seen any for astronomers. The categories for Jewish people, however, have been treated a bit differently. If I nominate Category:Mathematicians by religion for deletion, I will include all of its subcategories except Category:Pythagoreans anyway (just to be unbiased towards all currently-practiced religions, if nothing else). Dr. Submillimeter 22:30, 13 April 2007 (UTC)
Thanks for this answer. The case for some of these subcategories of mathematicians (especially Jewish and Muslim) is a bit delicate, but maybe we can just see what happens at the CFD. Geometry guy 22:50, 13 April 2007 (UTC)

Spiritual beliefs are not necessarily irrelevant to how a mathematician thinks about the status of mathematical objects and of the infinite -- and this can affect his research as well; not the content of his conclusions, perhaps, but the way he interprets them, and what questions he chooses to study. --Trovatore 01:07, 14 April 2007 (UTC)

I agree that for some people that religion is an important factor in their careers. However, these categories, as they are currently named, will be used for any mathematician who can be described as belonging to a specific religion, regardless of whether that religion had any influence on the person's career. For example, Carl Friedrich Gauss is currently categorized under Category:Christian mathematicians. However, it is unclear from his article as to whether Christianity was at all influential in his career. I am certain that I can identify others.
This is the general problem with these religion/career categories; despite the intentions of a few editors of wanting to restrict these categories to monks or scholar-priests who worked in mathematics, the categories will be used by other people for any articles that appear to describe mathematicians who were a certain religion, even if the religious beliefs had no influence on their careers or thinking.
I will hold off on nominating these categories for deletion a little longer. I would like to see what happens with some currnet discussions, and I would like to see if anyone else comments here. Dr. Submillimeter 22:43, 16 April 2007 (UTC)

Scholarpedia

I stumbled across Scholarpedia today, its a wikipedia type thing written by academics. The coverage seems patchy coving computational neuroscience, dynamical systems[30], and computational intelligence. But the articles that exists seem to be more in depth than here. They have quite a destinguised list of authors Milnor, possible Lonez Conway and Mandelbrot. --Salix alba (talk) 16:43, 14 April 2007 (UTC)

Their articles are under full copyright, by the way [31]. Oleg Alexandrov (talk) 16:54, 14 April 2007 (UTC)
The calibre of authors they're approaching -- and getting to sign up -- for the dynamical systems articles is impressive. Many of the defining people in the field. Their advertising model is interesting too -- matching on-topic ads from Amazon and Google to articles by people of the very first rank in the field. With luck they may generate enough cash-flow that they may actually be able to pay their contributors and their server bills. Which would be a good thing, because Scholarpedia is generating reliable and available online material written by very impressive people, including coverage even for its version 0.1 of topics we still haven't reached. (Dynamical systems has always been a somewhat weak area for WP; but even in other areas they're covering subjects that we don't).
On the other hand, SP is a very different beastie to Wikipedia. Even if their article's were available GFDL (which they aren't), the interesting thing is that I think (and I hope and trust) our eds would want to heavily re-write them -- to make them much more integrated, more accessible for typical readers coming in from other WP articles, more geared to answering typical readers questions, and generally just differently pitched somehow. And it makes me appreciate the real freedom of the anyone-can-edit ethos at WP, because I wouldn't dare touch any of those contributior's articles at SP, even though I'm not sure they all play particularly well together (or are even very well laid out).
So while I'm glad that there's now an online article on Fuzzy Logic by Lotfi Zadeh himeself up at SP, an article on K-S entropy by Y. Sinai, etc., they are useful resources, but they are not actually what I would like to see as articles for WP. Jheald 21:05, 14 April 2007 (UTC)
Link and learn. Charles Matthews 11:47, 15 April 2007 (UTC)
(via edit conflict) One of the things which intrigue me about Scholarpedia, and possibly one of the reasons why they get these top-notch authors, is that they use a traditional peer review system. After the article is written, it's sent to two referees who comment on it. The article is only accepted after the referees give the go-ahead. This is called "initial peer review" in their instructions for reviewers, which say that it allows "authors to list their papers as peer-reviewed in their CVs and resumes". -- Jitse Niesen (talk) 11:52, 15 April 2007 (UTC)
I doubt John Milnor needs to pad his CV! Perhaps it's simpler: survey articles that can be updated and are on the Web probably seem sensible to experts. Charles Matthews 19:37, 15 April 2007 (UTC)
Of course it wouldn't add to John Milnor's CV. I see now that I chose my quote poorly, giving the impression that I think that Scholarpedia's authors contribute to fill their CV. The whole paragraph is "Scholarpedia enforces the same rigorous anonymous peer review process as most printed journals. This is done primarily to insure the accuracy and quality of information, and to allow authors to list their papers as peer-reviewed in their CVs and resumes."
I agree that "survey articles that can be updated and are on the Web probably seem sensible to experts". The question is: why does Scholarpedia attract experts that do not write for Wikipedia (as far as I know)? I suspect that this is partly because Scholarpedia's model (in particular, peer review) is closer to what they are familiar with, while Wikipedia is just a wacky idea. Another factor may be that Scholarpedia actually asks people to write for them. It's harder to decline when you get an email saying "The contributors to the Scholarpedia website have decided that you are the best guy to write this article. Would you please do so?" -- Jitse Niesen (talk) 03:26, 16 April 2007 (UTC)
I think "lack of familiarity" is too kind to Wikipedia. We can look at examples of experts who came here, contributed, then gave up and departed. Suppose Milnor devoted two weeks to writing a survey of exotic spheres, complete with expert insights and a well-chosen bibliography. What would happen to it in the next six months here? Some possibilities:
  • A vandal adds an illustration; you know the kind.
  • Another vandal blanks the article and replaces it with homophobic hate.
  • Some crank inserts a pet theory.
  • The inline citation squad splatters it with {{fact}} tags, ignoring the bibliography.
  • Any new insights not previously published are removed as violations of WP:NOR.
  • Several irate readers demand that the introduction be made more "accessible".
  • Some of them, who know nothing of the topic, and little of English, take turns rewriting it.
  • A revert war ensues, Milnor is lambasted for WP:OWN, and blocked for WP:3RR.
Need I go on? Do I exaggerate? Wikipedia is not kind to expert scholars. As recently mentioned, topics like general relativity theory fare worse than mathematics, and topics of interest to a wider audience fare worse still.
I wonder if Wikipedia may be like peer-to-peer music; it fills a temporary void. The quality is not great, and we would prefer better offerings, but nothing else was adequately addressing our needs. Where, freely available on the web, do I read about exotic 7-spheres? If nowhere else, perhaps Wikipedia. --KSmrqT 04:43, 16 April 2007 (UTC)

I agree with the general sentiment, but let's not get carried away. Since you've chosen the exotic sphere article as an example, let's look and consider if any of these things has happened to it. Vandalism? Not really. Crank theories? No. Inline citation problems? No. Accessibility complaints? No. Illiterate ignoramuses revising the page? No (except me perhaps). As for the problems with say, Milnor putting in his new cutting edge research (which has somehow not made it into the literature after all these years...), I doubt he would have any trouble understanding the problems with that; in my experience, mathematicians tend to be good at realizing these things, even those that haven't edited Wikipedia much. Certainly after one of the people who normally edit the page pointed it out to him, I can't imagine Milnor unreasonably insisting on a revert war and being eventually blocked (he seems calm enough in person).

So, in summary, I would imagine if some famous mathematician were to edit Wikipedia (and somehow I can imagine this extremely well even with a lack of imagination...) I would expect little problems. The math portion of Wikipedia functions quite differently than some other parts though. So I would agree there is a kind of expert problem. But I don't know how much of a problem it is to us. And let's not disparate the exotic sphere article too much, eh? It's not bad; it's informative, gives some good references. Certainly one can find a fairly elementary introduction by Milnor (in one of those MAA lecture series from the 70s) that is wonderful, but that's a very high standard to try and match.

In your hypothetical example, I imagine some people would read Milnor's article and it would get promoted to A-class :-). --C S (Talk) 07:16, 16 April 2007 (UTC)

I was certainly thrilled by what I read above concerning Scholarpedia, but before making your far-reaching judgements about its advantages and disadvantages viz. Wikipedia, take a look at the product. It touts itself as the new, wonderful model,
The approach of Scholarpedia does not compete with, but rather complements that of Wikipedia: instead of covering a broad range of topics, Scholarpedia covers a few narrow fields, but does that exhaustively.
Well, the first 3 links in the Differential Equations part of (supposedly, exhaustive) Encyclopedia of Dynamical Systems are Ordinary Differential Equations, Boundary Value Problems and Initial Value Problems. The first is worse than a stub: it's an announcement of the authorship; the second is a bit better, having a potential author and potential table of contents (with typos); the third (finally) is an article, but it jumps straight off into numerical solutions, with no explanation or motivation. I don't want to imply that the authors or curators lack qualifications, but let's put it this way: there is no Milnor (or anyone of comparable stature) among them. For the time being, I'd regard the site as a half-baked imatation of Wikipedia, with ambition, but uncertain future.
I have to differ with you about the authors. I have some history in nonlinear systems, and I was blown away by the calibre of people they have signed up - these really are the first team, people who defined and interpreted and are leading the subject. And Scholarpedia haven't signed up just a few: they've signed up dozens and dozens and dozens of them, and matched them to the most appropriate topics.
Kicking SP because most of the articles are only stubs seems premature: most of the topics in dynamical systems appear only to have been commissioned last month, or to be still going through the commissioning process. But most of the authors who have been commissioned are aiming to deliver in the next few weeks. If you look again in June/July it may be quite a transformation. (In contrast, how may WP articles now stubs will reach Good Article status in that time ?)
Where I think you might have more of a point is perspective. WP can't call on this calibre (or quantity) of talent, would take years to evolve to even mark out with stubs a survey this detailed, constantly faces articles losing their shape as more details are added that don't quite fit the original plan, and frankly, well, it's a rare article in a technical subject here that couldn't be substantially improved. But what WP does have, like a sandstorm smoothing a stone, is continual pressure to make things more accessible, and to make different articles fit together better, and to make articles appropriate for the pages linking into them. That matching of individual articles to a multiplicity of entry perspectives, and making them play together at a category-wide level, is what I would currently see as the most significant weakness in SP (version 0.1), and its authored approach. Lots and lots of old-fashioned editorial smoothing required - casting and re-casting of leads and intros to give more perspective and accessibility. Jheald 12:28, 16 April 2007 (UTC).
The larger point that was touched upon by User:Jitse Niesen is more interesting: why would the best of the experts write something for a web encyclopedia? I think that this question is incorrectly posed: given the spread of electronic publishing, TeX, arXiv and all that, it's remarkable how little of this is occurring so far! Now, I don't believe for a second that a world expert in a certain field needs any of this "peer review" hullabaloo to somehow validate their survey papers. In fact, it seems that there is a certain aura of purity about "peer reviewed publications" in public sentiment outside of academia, bordering on worship. Very few serious mathematicians rely on peer review to justify their work (there are some notable exceptions). Contributing surveys by invitation, on the other hand, has a long and distinguished tradition. I have little doubt that it can be extremely successfully transferred into electronic medium. If Wikipedia (or mathematics project) wanted to toy with the idea, it's quite feasible to invite the very same people to make a contribution, and quite possibly, many will agree.
On the other hand, I think that User:KSmrq's comments are very relevant. In my short (about one month) time on English Wikipedia I've seen pretty much the whole spectrum of his bullet points, some of which unfolded (or were mentioned) in this very discussion page! By the way, note that he was talking about perceived problems with original research, lack of clarity, undocumented statements, and so on, and being an expert in the field by no means shields someone for those kinds of issues! If anything,
  • a famous author may attract unwanted attention from cranks, vandals, and possibly, scientific foes;
  • an article on a popular topic will get scrutiny from legions of people who demand it to be comprehensible to everyone ("if it's in the news, why don't I get it? I graduated from high school and consider myself brilliant"), and I can easily imagine how having a high profile author alone can produce this effect.
Arcfrk 09:01, 16 April 2007 (UTC)
Warts and all, Wikipedia fills a need. I would not want that point to be lost. But to respond to C S: suppose I were to invite Marcel Berger[32] to write on geometry, as he has done with great appeal in his books; the article history forebodes ill, and I think his time would be better spent elsewhere. --KSmrqT 10:18, 16 April 2007 (UTC)
This has generated an interesting discussion! I tend to agree with C S that things are not so bad in the mathematical oasis of WP. Vandalism is not intensive enough to be a problem: just hit that undo button and it is gone. And I've noticed that for every anonymous IP user who blanks a page or adds something scatological, there will be another who fixes a typo while browsing.
As for credit and peer review, one of the reasons that I contribute anonymously is that I don't want credit for any of my contributions. Also, if I were to be a named or invited author in article, I would want to maintain control over the article. So I'm not sure the wikipedia model is compatible with soliciting surveys. I like the WP model, but I think you need to have the right attitude/character to enjoy contributing here as an expert. I was recently browsing through the talk page at Lorentz group and I can see why Chris Hillman left. You have to be very flexible to contribute to WP. It also helps to be not just civil, but to make an extra effort to be friendly with other editors, especially when you disagree with them.
One area where I think WP lets mathematics down is in its desire to be a "general encyclopedia" in the Encyclopaedia Brittanica model. However, WP is so much larger than EB that it is really a whole new thing: a union of specialized and general encyclopedias. The mathematics coverage here is already becoming comparable with the Springer Encyclopedia. Unfortunately the generalist model has resulted in policies and guidelines which are not relevant or appropriate for mathematics. The whole concept of a featured article is totally unsuited to most mathematics articles, and it is not surprising to me that the few FAs we have are mostly on elementary subjects or are biographies. Having recently witnessed an FAC, and the inline citation crowd adding {{fact}} tags to any sentence which is not utterly bland, I have no desire for any article to which I have contributed significantly to become a featured article.
Perhaps we need our to define our own standard for the ultimate article, the FMA perhaps? Geometry guy 11:26, 16 April 2007 (UTC)
In general I don't think wikipedia is the right place for most academics. However I do think that they can help in someways. I've had good experience with emailing various academics and other experts on a number of topics, mainly for clarification on specific points, they have all been happy to help. Perhaps this a model, with us as a buffer between the academics ans wikipedia, work works best. --Salix alba (talk) 12:49, 16 April 2007 (UTC)

One point that I think is particularly relevant to mathematics here. The aim is not so much to have 'great articles' but a great piece of hypertext. So that (for example by the end of this decade) it would not be an empty boast that cutting-edge research mathematics can be referred back to definitions by an unbroken chain of blue links. Deligne said the proof of the Ramanujan conjecture would write out as 1000 pages of graduate level mathematics. We have a new model for making that less scary. Charles Matthews 15:51, 16 April 2007 (UTC)

Absolutely. By a quirk of fate I ended up doing interdisciplinary research, and ofter need to study small parts of new fields in a hurry - and fan out to the basic concepts needed, but no wider than that. Wikipedia with its blue word links is priceless, warts and all. Scholarpedia has more classical survey articles. There is a place for both. All these wikis are social experiments, and only time will show which equilibrium each one will hit. One aspect that Wikipedia is missing - when a professional mathematician spends a significant time on something he/she needs to take credit for it. Time is not free and even if the CV is thick the yearly increments do count. I write it off to paying back, public service and education, Wikipedia will make one a better writer over time. But from my short time here, many of us seem to be in the stage of their careers where they should seriously consider spending more time on writing journal papers than on Wikipedia in order to get that tenure or promotion. [added] A credit taking mechanism like Scholarpedia has would help and may attract more expert contributors. Jmath666 01:18, 17 April 2007 (UTC)

What do you mean by a credit-taking mechanism? Scholarpedia offers you an option: although you need to use your real name to register and you need to log in to edit, you can nonetheless edit either anonymously (but while logged in) or with your name on your edits in the edit history. Michael Hardy 01:37, 17 April 2007 (UTC)

Something to show on the CV for the time and effort spent that the tenure committee would consider. I have seen more than one case when someone was giving time and effort to noble things but the papers were not there so the ax fell. Authorship is more important than edits of course. I do not need that personally, but my guess is many of the best contributors here might. That may be a factor in favor of a model like Scholarpedia. Time will show. Jmath666 01:56, 17 April 2007 (UTC)

I for one don't think any tenure committee is going to be impressed by time and effort spent on Wikipedia or Wikipedia-like systems. Giving some way to give people credit on their vitae for those efforts is just going to lead to the committee asking why they aren't spending more effort on research. I think, as Jmath666 wrote earlier, that effort spent on WP is not only valuable community service but also that it is valuable practice in writing readably. But I don't see any kind of credit system as much of a draw, and I worry that such a system would lead junior into spending more time than they should in WP and hurting their careers. The way it is now, there's a clearer picture of what you're getting: a chance to help others understand the world better, but not really a step on the career ladder. —David Eppstein 02:17, 17 April 2007 (UTC)

There is an item for "service to the community" on our merit forms but it will not save the day. Maybe the whole business how we collaborate and publish will evolve towards some form of wiki. I see a pressure here towards original research all the time. Maybe the right way to parcel credit and control is would be the ingredient to spark the revolution. My group is already using CVS for pretty much everything, and I might set up a wiki instead for the next bunch; then it is only a step from a private server to online publishing. Jmath666 02:45, 17 April 2007 (UTC)
Tenure committees have different priorities at different schools, and in different departments within schools. Some give little weight to proven excellence in teaching; some give little weight to books authored. If the focus is on research, only peer-reviewed research publications count for much, and even then volume may not matter as much as perceived significance. Some journals garner more respect than others, and astute faculty judge accordingly. Like being kind to children and pets, contributing to Wikipedia can be a good thing; but don't expect it to help win academic advancement. --KSmrqT 04:32, 17 April 2007 (UTC)
This brings to mind the ideal of a gift economy which is frequently applied to open source projects and online communities. Both academia and wikipedia opperate (information) gift economies, reputation in each is largely measured by the amount of information produced. In academia this is measured by the CV in wikipedia its the list of articles i have contributed to on your user page and things like edit count. As seperate economies there is a poor rate of exchange between the two, academic credentials matter little to WP and edit counts matter little to academia.
I'm definitly with David on my motivation for editing WP in that my motivation is to help people understand mathematics and wikpedia (despight all its problems) to me seems the most effective way of acheiving this. --Salix alba (talk) 07:41, 17 April 2007 (UTC)

Mean information

The article Mean information has been nominated for deletion. Comment as you see fit. Anville 19:49, 15 April 2007 (UTC)

Variable Shape Geometry

I guess this does not qualify as encyclopedic content per WP:NOR. Comments? Oleg Alexandrov (talk) 22:22, 15 April 2007 (UTC)

I received the pamphlet I referenced not too long ago in school. The front cover said Variable Shape Geometry by Val Bess and that's all. I asked one math professor about it and he said that it (the geometry) is still being developed and the pamphlet is what the "creator" has 'discovered' so far. I really don't know if it was published or not but it seemed worthy enough for an article so I made one.Burnedthru 22:33, 15 April 2007 (UTC)
What makes it worthy? I'd like to know. There's not enough in the article for me to really understand what this geometry is about. It seems kind of strange to include something you found in a pamphlet here in Wikipedia before many other, more standard notions of geometry are covered. Rybu 22:57, 15 April 2007 (UTC)
Before what others? Burnedthru 23:00, 15 April 2007 (UTC)
If more information is required, I'd be happy to add some, it's just that I have no one to ask at this moment and am pretty busy. Burnedthru 23:04, 15 April 2007 (UTC)
Non-commutative geometry is a big branch of modern mathematics. Variable shape geometry on the other hand, I doubt many people have heard of. My point is, just because somebody produces a pamphlet and includes the word geometry in the title, does that mean it should be linked to the geometry Wikipedia page? I don't understand Wikipedia's mission well enough to answer the question. I don't think any reasonable encyclopedia would include variable shape geometry in a listing of geometries, since it's obscure. But maybe Wikipedia is happy to promote anything, regardless of how obscure it is. Take your article on variable shape geometry for example. Does isometry group make sense for this geometry, and if so, what is the isometry group of the geometry? That would help me understand what this geometry is about. As it is, the article tells me very little about anything, other than some guys name. Rybu 23:14, 15 April 2007 (UTC)
This should go straight to AfD. It is not a question of priority: deletion is clearly justified under WP:NOR and the article seems to me to be palpable nonsense. For a start, semicircles (oblate or otherwise) are not parabolas (and how are they defined anyway?). Then we have "Later on, triangles can be proven to be squares because of the Congruency Postulate, which is very complicated." The congruency postulate is, of course, not defined. The word "indiminent" does not exist, and one of the diagrams has a "parabola" drawn between lines which are not parallel, contrary to the unexplained hypothesis. Lets not waste any more time on this! Geometry guy 01:45, 16 April 2007 (UTC)
I agree. I nominated it for deletion, see Wikipedia:Articles for deletion/Variable-shape geometry. Oleg Alexandrov (talk) 01:56, 16 April 2007 (UTC)

Euler on infinite series

Someone has proposed that Euler on infinite series be transwikied to Wikiquote. I think instead the article should be expanded to be more than just a quote. Perhaps some of this pages public can contribute. Michael Hardy 23:58, 15 April 2007 (UTC)

Can't this be merged into Divergent series?  --LambiamTalk 06:50, 16 April 2007 (UTC)

Category:Complex systems

Category:Complex systems is on CfD [[33]]. --Salix alba (talk) 15:01, 16 April 2007 (UTC)

Since I nominated the category for deletion, the category has been cleaned up, and a solid justification has been given for its use. It no longer looks like a category to collect anything that is just "complex" and a "system" according to the casual reader, and I would certainly not attempt to delete this category if it remained this way. However, it would be good to avoid having people put things like Category:Role-playing game systems back into the category because "they are called systems, and they look complex" (which describes why some articles and subcategories were in this category before clean-up). What are people's thoughts on renaming this as Category:Complex systems studies so that the category stays focused on the field of complex systems and does not become a category for anything named a "system"? Dr. Submillimeter 15:16, 18 April 2007 (UTC)
This may be a way forward, although I think something like Category:Complex systems science or Category:Complex systems (science) would be better. Geometry guy 17:16, 18 April 2007 (UTC)

I think the name as it is is fine, it is what people in the area use and it is not ambiguous with any other meaning for the same phrase. If the problem is people not knowing the technical meaning of the phrase and guessing that things belong when they don't, wouldn't it suffice to add appropriate text to the category page? —David Eppstein 17:22, 18 April 2007 (UTC)

The approach that some people take to categorization is similar to jamming a square peg through a round hole. If the category name vaguely seems to describe an article, then some people will stuff that article in the category even if it is inappropriate. Explanatory text may limit the problem, but some people will ignore the text anyway. Renaming the category with a less ambiguous name is a more robust solution. Dr. Submillimeter 17:46, 18 April 2007 (UTC)
If it must be moved Category:Complex systems (science) sounds good to me, Complex systems studies does not work for me as no one uses that term. BTW the category seems only weekly linked in the mathematical should it be included in Category:Chaos theory or Category:Non-linear systems. --Salix alba (talk) 18:55, 18 April 2007 (UTC)

Warel?

Please consider this list of edits which hits all of WAREL's pet topics. I didn;t see any that looked harmful; but I can't tell where the ja: links are going. Would people keep an eye on this? Septentrionalis PMAnderson 23:20, 16 April 2007 (UTC)

Of the first three ja: links I saw, one was valid, one was a change to the literal translation of the English title, which was a redirect at ja:, and one was a translation that didn't seem to have an article at ja:. In other words, the links seem to be made without any reference to existence of Japanese articles. JPD (talk) 10:58, 17 April 2007 (UTC)

12988816 (number) is nominated for deletion

12988816 (number) is nominated for deletion. The AFD discussion is here. CMummert · talk 15:55, 17 April 2007 (UTC)

Arabic/Islamic mathematics

Nationalists are trying to move this article to a silly title again. —Ruud 23:24, 17 April 2007 (UTC)

The article used to have the name "Islamic mathematics" for most of its existence. This is a rather common name for the subject (I get 19300 Google hits for "Islamic mathematics" versus 16200 for "Arabic mathematics"), and hardly a silly title. You yourself moved History of mathematics in Islamic culture to Islamic mathematics on April 28, 2006.[34] Then, on March 10 you moved Islamic mathematics to Arabic mathematics.[35] Why? Was there any discussion on this, and was a consensus reached? When User:Jahangard moved it back, complaining that the move was unilateral[36], you immediately reverted this, as far as I see without discussion why "Islamic mathematics" is a worse title than "Arabic mathematics"[37]. Was that wise? It looks like your March 10 unilateral move triggered the proposal to rename the article from "Arabic Mathematics" to "Mathematics in Medieval Muslim World". On the talk page, the supporters of the (ill-advised) proposed renaming appear to favour "Islamic Mathematics" over that long-winded title. My suggestion to you is to undo your last move, and try to obtain consensus that "Islamic mathematics" is to be preferred over "Mathematics in Medieval Muslim World". If such consensus has been reached, emotions have come down, and you still think "Arabic mathematics" is the best title, open a discussion about it.  --LambiamTalk 06:49, 18 April 2007 (UTC)
I think both "Arabic mathematics" and "Islamic mathematics" are fine (I personally even prefer the term Islamic mathematics, my move last month was motivated by more pragmatic reasons and, given the lack of dedicated editors of this article, more a case of WP:BOLD than a "unilateral action".) The proposed move is to "Mathematics in Medieval Muslim World", however. —Ruud 08:21, 18 April 2007 (UTC)
I was probably too frustrated yesterday and should have approached this in a more calmly and with more tact. I would appreciatie it, if some looked at it with a fresh look. —Ruud 09:09, 18 April 2007 (UTC)

Question on Relation notation

I've always seen a relation shown as something like x~y on some set S. And that this relation is an "equivalence relation" iff it is reflexive, symmetric and transitive. So that for instance you could have x~y if x<y on the integer set Z. So this relation would not be an "equivalence relation" since x is not less than x so x~x is not true and so ~ is not reflexive. So ~ is a relation but not necessarily an "equivalence relation". But the article on the following articles seem contradictory to this saying that ~ alone denotes an equivalence relation:

  • Equivalence relation: An equivalence relation between a and b is often denoted as "a ~ b" or "a ≡ b".
  • Tilde#Mathematics: In mathematics, the tilde, sometimes pronounced "twiddle," is often used to denote an equivalence relation between two objects. Thus "x ~ y" means "x is equivalent to y". (Note that this is quite different from stating that x equals y.)

Is there something I am missing here?--Jersey Devil 01:23, 20 April 2007 (UTC)

It's fairly rare to use the tilde for a relation that's not an equivalence relation, but you won't go to jail for it. Not sure I really understand your question, though. --Trovatore 02:08, 20 April 2007 (UTC)
You may not go to jail for it, but the physical world is not what one ought truly be concerned with. Rather one's soul. There is a very special section of Hades reserved for those that use a tilde for a non-equivalence relation. And it's the section that is not filled with interesting people. --C S (Talk) 21:52, 21 April 2007 (UTC)
I agree, x~y almost always means an equivalence relation. But suppose a broad survey finds that one third of the uses are for relations not satisfying equivalence (a generous estimate); the two "often" statements quoted are no less correct. (Note the word is "often", not "always".) As a practical matter, we are unlikely to be confused by seeing a "~" used with uncertain meaning, because authors habitually tell us the meaning they intend. --KSmrqT 03:44, 20 April 2007 (UTC)
When I've seen ~ used, there really is an idea of equivalence involved -- not just a generic relationship. Two states in a communicating class in a Markov chain are "equivalent"... or whenever you have equivalence classes, for example, in the field of fractions (which, even though 1/2 and 2/4 are fractions of different integers, they are equivalent). In your example, x<y, this also fails because of symmetry (that if x~y then y~x, that is, x<y and y<x, which is clearly not true). However, even though < is not an equivalence relation, the relation ≤ over the real line is. I don't see the contradiction in the examples you give. - grubber 03:19, 20 April 2007 (UTC)
No, "≤" is not an equivalence relation, since it also obviously fails symmetry. Paul August 03:57, 20 April 2007 (UTC)
Grr, of course. My bad :) - grubber 17:17, 20 April 2007 (UTC)
Don't worry we all have mental lapses - mine come more and more lately. The distinguishing property between "<" and "≤" that you were probably thinking of is antisymmetry, which "<" fails, but "≤" satisfies, thus making the latter, but not the former a partial order. In fact , of course, "≤" is the archetypical partial order, hence the symbol "≤" is often used to represent any partial order, much like "~" is used to represent any equivalence relation. So there is that connection as well. Paul August 15:39, 21 April 2007 (UTC)

The ~ may be very often used to express equivalence relations, as the article says, but this does not contradict the fact that it is sometimes used for any relation, equivalence or otherwise. The confusion is simply that mathematical notation varies in different places and contexts. Perhaps the Tilde article could be updated to reflect the more general use of the symbol, but apart from that I don't see any issue at all. JPD (talk) 11:24, 20 April 2007 (UTC)

Strange edit at Relativity of simultaneity

Someone had made word-for-word the same edit in general relativity, which I promptly removed. Its applicability to GR was even more dubious than its presence in the relativity of simultaneity. Silly rabbit 14:48, 23 April 2007 (UTC)
I've now seen it at History of special relativity too -- that just didn't look right. So I'll take it out and direct further discussion to Talk:History of special relativity#Connection with set theory?. --Pjacobi 16:21, 23 April 2007 (UTC)

An invitation to categorize uncategorized math stubs

Hello. The categorization taskforce is trying to find WikiProjects interested in using the bot of Alai to identify mathematics stub articles which do not currently have a category (besides the stub category of course). If the project is interested, we could create something like Category:Uncategorized mathematics stubs which could then be categorized by people knowledgeable in the subject, thus reducing the risk of improper categorization. Please let us know on the taskforce's talk page if you're interested. Cheers, Pascal.Tesson 00:23, 23 April 2007 (UTC)

Category:Complex systems nominated for renaming

I have proposed renaming Category:Complex systems as Category:Complex systems (science). Here is my justification for the rename:

I previously nominated this for deletion on 13 April 2007, mainly because it was being used to categorize anything that could be described as "complex" and a "system" by the average Wikipedia user (such as "role-playing game systems"). This actually seemed to categorize things by name rather than categorize things that were related to each other. Following the nomination, several people familiar with the scientific field of complex systems explained that the field deserved a category and cleaned out the category. However, the category is still at risk for being used to list anything that could be described as "complex" and a "system", and it would be good to have the category focus speficially on the field of complex systems itself rather than gathering together everything that could be called a system (like the deleted Category:Systems, which was deleted following a 12 April 2007 discussion; see User:Jpbowen/Back up - Category Systems). After a discussion at Wikipedia Talk:WikiProject Mathematics, a couple of people suggested renaming this as Complex systems (science), which I now recommend as the new name for this category. Dr. Submillimeter 18:06, 19 April 2007 (UTC)
Although I don't have a strong view on the rename, I originally suggested Complex systems (science) as an alternative to Complex systems studies. A better suggestion has now been made: Complex systems theory. I think this choice avoids most of the drawbacks of the rename (it seems to me to be as harmless as the distinction between relativity and relativity theory), while retaining the benefits. Comments can be added here. Geometry guy 11:11, 25 April 2007 (UTC)

Karel de Leeuw

I came across this article on a mathematician while working on categories. (Don't ask how.) The article says little about why this person was notable, although I suspect that part of the reason why the person was notable was because he was a murder victim. I may nominate it for deletion, although first I have asked the article creator to improve the article.

Is anyone here familiar with de Leeuw's research? Was he notable in mathematics? From this standpoint of this person as a mathematician, should the article be kept, or should it be deleted? Dr. Submillimeter 20:59, 19 April 2007 (UTC)

Tenured mathematicians at Stanford (even back then) are very notable. I also spy a publication in the Annals and several in lesser (but still prestigious) journals. --C S (Talk) 21:39, 19 April 2007 (UTC)
I do not concur that "tenured mathematicians at Stanford ... are very notable." However, if C S is correct is correct as to publications, that should be adequate for notability. I'm just not sure. — Arthur Rubin | (talk) 21:55, 19 April 2007 (UTC)
Please note that WP mathematician notability guidelines appear to be far more strict than those in other areas. This is particularly the case for anyone who's made a name for themselves on the net, e.g. various luminaries in the Linux/open source world, or in the computer gaming industry. The list of accomplishments are often of the form "so-n-so wrote this-n-such piece of software", yet the software is not particularly deep, original or complex. Point-for-point, they'd be completely outclassed by thousands of utterly anonymous engineers. Or, to compare to academia, the accomplishments seem at best comparable to those of junior math professors at state universities, the kind of which get AfD'ed. Yet, internet fame seems to be a deciding factor. It seems to be all so very unfair... linas 00:05, 20 April 2007 (UTC)
Dr. Submillimeter is right: many more people are familiar with the story of his murder (linked in the article) than with his research. It was a very high profile case, in my opinion, deserving coverage in Wikipedia. Arcfrk 00:10, 20 April 2007 (UTC)
I think the murder does contribute to his notability (hard way to get it!) but he would deserve an article without it. --Trovatore 00:14, 20 April 2007 (UTC)
Questions of notability would be easier to address if the name were spelled properly: "Karel de Leeuw" should be "Karel deLeeuw", without the space. Then a web search would find this description of his life and contributions. --KSmrqT 03:55, 20 April 2007 (UTC)
He seems to have published under both spellings, so I don't know how you're picking which is the "proper" one. --Trovatore 05:48, 20 April 2007 (UTC)
Two factors: number of search hits (unreliable), and Stanford department remembrance. The article should mention both spellings, and should definitely draw on the information I linked above. I don't care enough to move it, but my leaning is it should be moved. --KSmrqT 05:57, 20 April 2007 (UTC)
Better than search hits is MathSciNet. Have you looked there? It was a long time ago, but when I looked there seemed to be more listings with the space than without. --Trovatore 06:00, 20 April 2007 (UTC)

By the way, does anyone know if he's any relation to Jan de Leeuw, who definitely should not have a redlink? --Trovatore 06:02, 20 April 2007 (UTC)

Could someone please expand the article to indicate how the person was notable? Dr. Submillimeter 11:12, 20 April 2007 (UTC)

Just to conclude this for the archives, deLeeuw is notable for two reasons: his research and his murder. I suspect that after a few decades the murder will evolve into urban legend, since it seems to express two emotions common to graduate students. He was well liked by most students, and his murderer was frustrated by 19 years of failure. As to his research, the article's list of selected publications occupies as much space as the text, which surely is enough. The biography is brief, but a Stanford faculty member whose advisor was Emil Artin at Princeton, who was a Fulbright Fellow at Cambridge, who spent time at IAS, and who was a coauthor with Walter Rudin — clearly this man had something to contribute. As for the spelling, both Stanford and the mathematics genealogy project omit the space, while his publications do not.
Violence and murder are too common a tragedy in the U.S., and the victims are too often the generous and gentle souls. Perhaps Moez Alimohamed deserves a page as well, especially as Penn established an award in his name. Sadly, he has only this major publication left to represent his contribution to mathematics. Contrast the worth of these two individuals with the 65 names on the list of Formula One drivers who never qualified for a race. From the pages of Spider-Man, who himself saw his beloved uncle murdered, "'Nuff said". --KSmrqT 21:21, 25 April 2007 (UTC)

I was bold, and moved it to deLeeuw, which most of the sources seem to use. Does anybody mind? If so, let's do WP:RM. Septentrionalis PMAnderson 05:29, 26 April 2007 (UTC)

Systolic geometry -- legitimate topic or link spam?

Please check out Systolic geometry. I noticed it when Katzmik (talk · contribs) twice put a link to it into Hyperbolic geometry. Both times I removed the link after looking at the article and not seeing any relevance to hyperbolic geometry. Apparently, Katzmik is Mikhail G. Katz, author of a book linked to by the article. He did not create the article, but he has done most of the edits to it. Do you think that this is a legitimate topic or is it just link spam? JRSpriggs 07:54, 25 April 2007 (UTC)

i think there is no reason to assume it's spam. requesting for clarifications from Katzmik (talk · contribs) seems to be a sensible thing to do. there's a section Systolic geometry that hints at some kinda relationship with hyperbolic geometry. perhaps Katzmik (talk · contribs) would be willing to expand it. Mct mht 09:29, 25 April 2007 (UTC)
This is an entirely legitimate topic, as far as I can tell. It's probably worth drawing the author's attention to WP:NOR. I think the AMS monographs are peer reviewed, but it might be best if the book is only used as a secondary source for the article.
As for the relevance to hyperbolic geometry, for one thing, the length of the systole will be a hyperbolic invariant. Geometry guy 12:08, 25 April 2007 (UTC)
If the AMS is willing to publish something, it ought to count as a reliable source for Wikipedia. The article is actually pretty reasonable, and lists numerous sources (there are some minor OR issues that would come up in an FA review, but this is a common problem). I agree with R.e.b.'s comment below that when experts want to improve articles in areas they are familiar with, and they write quality articles like this one, there is no reason to discourage them. CMummert · talk 18:39, 25 April 2007 (UTC)
Systolic geometry is a legitimate topic, it is indeed related to hyperbolic geometry, and Katzmik (talk · contribs) is an expert on it, who should be thanked rather than insulted for his efforts. R.e.b. 16:42, 25 April 2007 (UTC)

We have assume good faith for a reason. This case illustrates why. Charles Matthews 16:50, 25 April 2007 (UTC)

It looks perfectly legitimate to me. The basic definition is stated in such a way that it should be instantly comprehensible to everyone (except non-mathematicians, maybe) and that's more than can be said for some math articles. This seems like a good reason why an author should not be forbidden to put in an external link to his own book. Michael Hardy 20:53, 25 April 2007 (UTC)

Capitalization question

I was reading ordered field and noticed that the "Archimedean property" was capitalized, whereas in my Lang Algebra book, it is not. So, I noticed:

I had always learned that when the property is modified (like with -ian), that it loses its "properness" and should be written lowercase -- and I have never seen abelian capitalized. But, on the other hand, I have always seen Gaussian written capitalized. I would prefer to never capitalize such adjectives (but that could look very strange with Gauss, Hamiltonian, Hilbert space, etc) Any ideas or has this been discussed before? - grubber 16:02, 18 April 2007 (UTC)

Capitalization of proper names in mathematical terms is sort of inconsistent. You say, for example, that "Archimedean property" is always capitalized. Nonetheless, number theorists routinely refer to non-archimedean valuations (actually, that article uses both capitalizations). I've seen both "Gaussian" and "gaussian", and in rather old books, also "Abelian" rather than "abelian". I can't remember who in particular I heard this from, but it's said that a lower-cased name in this context is a sort of honor, that the term has become so standard that it's not a matter of professional courtesy anymore, but simply a fact of life that, e.g., commutative groups are "abelian". In light of this, it's not really something that Wikipedia should regulate, in my opinion. Ryan Reich 16:32, 18 April 2007 (UTC)
This is to confirm what Ryan Reich said. I have two old group theory books (Herstein, and Hall). The first author refers to abelian groups, and the second uses Abelian groups. I don't think there's a standard in the literature, so Wikipedia ought not impose one. Oh -- I'm pretty sure I've seen both "Gaussian noise" and "gaussian noise" in physics/electrical engineering contexts. DavidCBryant 16:44, 18 April 2007 (UTC)
I would disagree here. As far as I know, not capitalizing "abelian" far outweighs capitalizing, so there is a pretty widespread convention; as indicated by Ryan's comments and your example, some old books may use capitalization. In fact, as pointed out by Dave Rusin in a nice sci.math post[38] it is the only name in the MSC that is not capitalized; I took a quick look and certainly abelian is not capitalized except when beginning the name of a category.
I'm not sure about other terms. If indeed it is a matter of preference, then Wikipedia ought not to impose as David said, but it would be silly to take this ambivalence to the extent of overturning a nearly unanimous convention. --C S (Talk) 17:01, 18 April 2007 (UTC)
(edit conflict) Once upon a time I was told such a rule too. But it's a rule many people don't use! As for "archimedean", I've seen it both ways. "Hilbertian field" can be either way too. It's interesting that indeed Gaussian (even in other cases as in "Gaussian integers") and Euclidean (in "Euclidean domain") is always capitalized. The usual way to find out if something is capitalized is to put everything in lowercase, submit it to a journal, and see if someone busts a gasket. I was told an interesting philosophy behind this lowercasing: that putting a name in lowercase is bestowing even greater honor upon the person; unfortunately an editor did not see it that way. So it goes.
Interestingly enough, I found this entertaining blog post [39] which has a comment which led me to Abelian group, where the note on typography states, "Among mathematical adjectives derived from the proper name of a mathematician, the word "abelian" is rare in being expressed with a lowercase a, rather than A (cf. Riemannian). Contrary to what one might expect, naming a concept in this way is considered one of the highest honours in mathematics for the namesake." Huh, no citation needed tag? ^.^ --C S (Talk) 16:52, 18 April 2007 (UTC)
(edit conflict) I was once told that it is the great honor of Abel that his was one of the few non-capitalized math names turned adjective. This is discussed outside of WP, but I don't think it is in WP:MSM, but maybe should be. Smmurphy(Talk) 16:56, 18 April 2007 (UTC)
I'm not suggesting that WP should be the body that determines the standard. However, it would be nice to have a standard that we use consistently in all mathematics articles on WP (and alternate usage notes where appropriate); for example, a few lines in Wikipedia:WikiProject Mathematics/Conventions to discuss which one is "preferred". I hope that it would not degenerate into a "British vs. American spelling"-esque debate, although you never know :) - grubber 17:04, 18 April 2007 (UTC)
I agree with Ryan Reich that this is not something that we should regulate. On the other hand, I would not like to see the use of unmodified proper names without capitals such as hilbert space. I quite like the convention to decapitalize words derived from proper names, but not the proper name itself (even when used in a noun phrase like Hilbert space). Hence: Hermite polynomial, hermitian form, Gauss map, gaussian distribution, Abel-Jacobi map, abelian group, Klein geometry, kleinian group. (This convention is systematically used in French.) Geometry guy 17:11, 18 April 2007 (UTC)
PS. More importantly, though, Abel-Jacobi map is still a redlink! Can someone write a stub, or find a suitable redirect?
I'm writing an article right now. If anyone else is interested, wait a bit until I'm finished to avoid a conflict and then join in. Ryan Reich 17:40, 18 April 2007 (UTC)
The following, found in the Style manual of the U.S. Government Printing Office,[40] corresponds to what I believe to be the general rule for English:
3.3. Derivatives of proper names used with a proper meaning are capitalized.
Roman (of Rome) • Johannean • Italian
3.4. Derivatives of proper names used with acquired independent common meaning, or no longer identified with such names, are set lowercased. Since this depends upon general and long-continued usage, a more definite and all-inclusive rule cannot be formulated in advance.
roman (type) • brussels sprouts • venetian blinds • macadam (crushed rock) • watt (electric unit) • plaster of paris • italicize • anglicize • pasteurize
As far as I know this is also the prevailing rule in the U.K. Unfortunately the application of the rule is not authot-independent. While I write "angora wool", "benzine" and "cardigan sweater" without thinking of Ankara, Benz or Cardigan, I can't see "abelian" or "Abelian" without thinking of Abel. But in any case, I think we should preferentially follow general rules as laid down in authoritative style guides (rather than the possibly haphazard choices made by authors of mathematical texts) unless there is a compelling reason not to do so. (And note that in view of the completely different rule for French, texts by semi-French authors like Lang are perhaps somewhat suspect.) --LambiamTalk 19:26, 18 April 2007 (UTC)
Is there an authoritative style guide in mathematics? I remember looking at some Oxford general science writing guides, but they were not exactly helpful in this regard. While it's true that authors could be inconsistent (even between different texts of the same author!), but usage and grammar are not frozen in time, either: for example, capitalization of nouns was a lot more common even 100 years ago. Thus it may be preferable to consult current literature, with all the attendant faults, to using outdated manuals. Also, the last comment about Lang is a bit perplexing: it's true that he had peculiar accent, yet I never heard any implications that his English had been influenced by French or any other language, certainly, not in the context of his prolific mathematical writing (only small Bourbaki part of which was done in French, as far as I know). Arcfrk 23:25, 18 April 2007 (UTC)
Surely the rules are not topic-dependent? If it is Archimedean point with a capital A in philosophy, then also Archimedean property in mathematics. If it is Hamiltonian economic program in economic history, then also Hamiltonian path in maths. Rather than consulting outdated manuals, what about contemporary manuals that are kept up-to-date? The GPO Style Manual referred to above is from 2000.  --LambiamTalk 03:07, 19 April 2007 (UTC)
The problem is that different contemporary style guides almost certainly disagree. My opinion is that the best we can do - and this is not sarcasm - is to make each article internally consistent, and not worry about global consistency. CMummert · talk 03:14, 19 April 2007 (UTC)
I dont think we'll have a universal solution, but for each word I think we should make it consistent throughout WP. - grubber 03:16, 19 April 2007 (UTC)
I must agree with Arcfrk below; any given word is subject- (and author-) dependent. For example, I believe Frank Harary uses hamiltonian, and the usage in graph theory is clearly divided. We represent the state of mathematics best by being inconsistent. Septentrionalis PMAnderson 15:09, 26 April 2007 (UTC)
My impression is exactly that the rules are both subject-dependent and time-dependent (different editions of the same book may use different conventions), and mathematical usage tends to diverge from more general science usage. Arcfrk 03:44, 19 April 2007 (UTC)
Replying to your question on style guides in mathematics: The only one I know is Nick Higham, Handbook of Mathematical Writing, SIAM, 1993. Not a style guide, but a good reference for the finer points of typography, is Donald Knuth, The TeXbook. I also use P.R. Halmos, "How to write mathematics", Enseignements Mathématiques, 16:123–152. Perhaps we should start a list at Wikipedia:Manual of Style (mathematics)? -- Jitse Niesen (talk) 14:23, 19 April 2007 (UTC)
Yes please! Paul August 14:50, 19 April 2007 (UTC)

AfD: Mathematical landscape

Mathematical landscape has been nominated for deletion. Comment as you see fit! Anville 15:34, 26 April 2007 (UTC)

Calculi versus algebras

What is the difference between caluculi (e.g. propositional calculus,predicate calculus,proof calculus, and the various comp-sci calculi) vs. algebras (Boolean, heyting, etc)?

I was hoping to maybe find something on wikipedia explaining the difference, but I couldn't find anything. Brentt 03:03, 26 April 2007 (UTC)

Well, there's an ambiguity here that's caused us lots of grief in the past. "Boolean algebra", taken as a mass noun, means pretty much the same as the propositional calculus. Our article on Boolean algebra in that sense is (supposed to be) at Boolean logic, though the criteria for including information in that article are not particularly clear.
On the other hand, a Boolean algebra, count noun, is a mathematical object. It's not a calculus at all; it's an algebraic structure, like a group or ring. Not sure if I've helped, but it's a start; maybe we can narrow down what your question means. --Trovatore 03:17, 26 April 2007 (UTC)

I have always associated the word "calculus" with a method to manipulate strings of symbols in a meaningful way. There are "transformation rules" that tell you how to convert one string into another string. Not every transformation may be suitable for every string - you have to follow some rules. This matches the way that Newtonian calculus, lambda calculus, proof calculi, propositional calculus, etc. work. An algebra, on the other hand, is a set with operations such that any two elements can have the operation applied to them. In some cases, you can make up a semantics for the calculus that show that when the strings represent elements of a certain type of algebra then the transformation rules preserve some algebraic properties. But this is a very loose connection. Is that your question? CMummert · talk 03:35, 26 April 2007 (UTC)

Yeah, actually your first three sentences here are pretty much what I was getting at. The mass-noun sense of "Boolean algebra" is really a calculus; the count-noun sense is an algebra. (We should perhaps reconsider making Boolean algebra a disambiguation page, because this keeps biting us from time to time.) --Trovatore 03:52, 26 April 2007 (UTC)
Isn't an operation sort of a inference rule though? Brentt 00:57, 27 April 2007 (UTC)
Not sure what you mean by that. Can you elaborate? Note that the objects on which you're performing the operation may not be things you can write down in a finite amount of space. --Trovatore 02:32, 28 April 2007 (UTC)
Most of elementary algebra (where "algebra" is the mass noun) consists of rules for meaning-preserving manipulations on formulas (strings of symbols). In that sense, the algebra rules are much like (for example) the rules of the differential calculus, and one might call it a calculus. The soundness of these rules corresponds to algebraic properties enjoyed by the mathematical structure (possibly an algebra) whose elements are denoted by the formulas. The mathematical structures (such as rings) and the calculi (such as high-school algebra) live in different universes. For a Platonist, the mathematical structure has an existence independent of human knowledge; it was discovered. A calculus, on the other hand, is a human construction that was invented.
To complicate things, strings of symbols are themselves also elements of carrier sets of various algebras (for example, regular languages form Kleene algebras), and so we can also "discover" and examine the algebraic structure of some calculi. Given the somewhat frayed ends of most interesting calculi, this is usually not a rewarding undertaking, but for the Risch algorithm it definitely was.  --LambiamTalk 04:15, 28 April 2007 (UTC)

FAC of Equipartition theorem?

Umm, hi,

This is surely off-topic here, but I'm hoping that people here would be kind enough to evaluate Equipartition theorem, which is a Featured Article candidate now. It's at the level of basic multivariable calculus, although there is a multidimensional integration by parts at one step of the derivation. Does the article read OK to you all? Any suggestions for improvements? Thanks ever so much for your time and trouble, Willow 21:58, 27 April 2007 (UTC)

Mathematics ratings and tables

It seems to be regarded as a positive thing to put {{maths rating}} templates on talk pages as a way of tracking progress in our task to provide a good range of high quality articles, with emphasis on the most important ones. However, I am confused by the current organization and would appreciate some links/clarification/discussion. The whole process seems to be intertwined with the separate but related selection of articles for the CD-ROM Wikipedia1.0, whose classification we use (modulo our additional B+ class).

At first this seems fine: I follow the "mathematics grading" link on a template to Wikipedia:WikiProject_Mathematics/Wikipedia_1.0 and find explanations of the grading, with helpful tables of how many articles there are in each class, analysed both by importance and field, automatically generated each day by a bot - great! When I follow links in this table to a particular class (A,B etc.), or importance level (low, mid etc.), I find myself on a category pages which automatically list the articles in the given category - also useful!

Finally I follow the link to geometry and topology and I see something which looks even more useful: a list of articles in my field, ordered first by decreasing importance and then by increasing quality (class), together with comments, presumably from the template on the talk page. Wow, this is the most useful page of all!

But then I notice that the page is incomplete (articles with ratings that I know are not there), and has an extra "Has template" column. The page appears not to be automated (indeed it is months out-of-date). Then I remember WP1.0 and guess this is some list of articles chosen to go on a CD-ROM. Is this right, or am I just confused? Wouldn't it be really useful to have pages like these which were updated automatically from templates on article pages? Wouldn't it be better to have an extra column "Selected for WP1.0" (which could be, and is usually, indicated on the article page)?

Forgive these mumblings if I have completely missed the point, but the current structure has left me very bewildered about what is going on. Geometry guy 21:01, 12 April 2007 (UTC)

These per-field pages are not related to WP 1.0; they are just for in-project use. They aren't (yet) automatically updated, mostly because I haven't gotten around to writing the code. There are no technical obstacles to doing the updates automatically except that the automatic versions would not include the "comments" that the current tables do. It would not be too hard to write the code to update them at the same time the main table is updated. CMummert · talk 22:29, 12 April 2007 (UTC)
This definitely seems a good thing to do when you get the time. We are now getting to the stage where the number of rated articles has reached the level where further sub divisions is necessary. --Salix alba (talk) 23:42, 12 April 2007 (UTC)

Many thanks for the clarifications. It would be great if these pages were automated (although the "algebra" one would be a bit long unless stub class or low importance articles were somehow omitted).

However, one of the most useful things about these pages is that comments are there. Now there is a "comment" field on the {{maths rating}} template. This does not separate the comment from the author, but that is not important. At least in principle, couldn't the "comments/updated/has template" columns be replaced by a single column with the "comment" field of the article template? I know it requires someone to do the work, but it would be very useful and might encourage editors to use the "comment" field more often, and keep it up-to-date. Geometry guy 09:44, 13 April 2007 (UTC)

The table is created by using a database query interface to get lists of articles with various properties and then cross-referencing those lists to generate the table. These queries doesn't put much strain on the database and are very fast. In order to get the comments, it would be necessary to download the actual source of the talk pages and parse out the comments, which is a much slower and technically more difficult operation. At least the first version of automatic update wouldn't do it. CMummert · talk 11:33, 13 April 2007 (UTC)

I see, that's a pity. Does that mean that if we moved to an automatic update regime we would lose the comments completely on the field pages, or would it be possible to write the code so that it checks the current field page for existing comments and writes them to the new page? (I guess that would be more work to do, though, because it involves parsing the field page.)

Would it be feasible to update comments from templates as a separate operation that happens less frequently? Weekly would surely be enough, or the bot could cycle through the list of fields to reduce the daily load (so each page would be updated every 11 days). Well, I know this is work, and work which I am not able to do, but I think it might add some energy to the project to have such a system for monitoring progress. I would at least be willing to go through (some of) the existing field pages and merge the existing comments into the templates on the article pages.

Also, I wonder if this is something that Snowolf and Snowbot would be able to do for us. Even a one-off update of the pages would be great. Geometry guy 15:54, 13 April 2007 (UTC)

There are two ways comments could be be done. It can be specified as an inline field in the template, its can also be done as a sub page. This has been done on Talk:Blaise Pascal, with Talk:Blaise Pascal/Comments as the sub page. If this structure is used then it becomes a trivial matter to transclude the appropriate comment page in the listings of articles, using {{Talk:Blaise Pascal/Comments}} etc.
It should not be too problematic to migrate articles to this latter fashion, a bot could do this. It would only need to run once so the server load would not be problematic. I've changed {{Maths rating}} to put articles with inline comments into Category:Mathematics articles with inline comments. That category could be checked periodically to complete the migration. --Salix alba (talk) 19:25, 13 April 2007 (UTC)

This is a clever work-around — nice one Salix alba! I've changed {{Maths rating}} to put articles with a comments page into Category:Mathematics articles with comments page. There are not so many of them yet, so I was able to go through them by hand, fixing them if necessary so that they are not also in Category:Mathematics articles with inline comments. It would be nice to have a third category with Category:Mathematics articles with no comments, but that required me to pluck up the courage to make a more substantial edit to the {{maths rating}} template, or for someone with more Template experience to do it before letting me the chance to mess it up ;) Geometry guy 15:50, 14 April 2007 (UTC)

I wasn't courageous enough so I just added a Category:Mathematics articles with no comments page. I also wasn't careful with the includeonly/noinclude issue so the template itself is an example. This is just a temporary fix to see where we are now. I will not be at all offended if someone reverts my edit! Geometry guy 20:08, 14 April 2007 (UTC)

I plucked up a bit more courage, and my ugly code appears to work, although it has the side effect of raising the "field" field slightly. I expect this is due to my lack of understanding of spaces and newlines in template code, and I hope an expert can fix it quickly (and improve my ugly nested code!): explanations on my talk page most welcome (and don't be afraid to be patronizing!). Meanwhile the temporary category Category:Mathematics articles with no comments page needs deleting (I don't think this needs to go through CFD since it contains no articles!). Geometry guy 21:23, 14 April 2007 (UTC)

Proof of concept

Salix Alba suggests migrating from inline comments to only using comment subpages. I have no objection to that. I don't know the historical circumstances that led to the current redundant system.

If the comments are all moved to subpages then there is no technical problem with making the field summary pages. I wrote some proof-of-concept code whose results are available at User:CMummert/Sandbox4. That page is entirely automatically generated. Please let me know what can be improved. CMummert · talk 15:06, 14 April 2007 (UTC)

This is fantastic! Thank you CMummert! The only suggestions I have are cosmetic.
  • A fixed width column for the article name would mean the coloured class boxes would line up nicely :)
  • I can see that splitting the page up into "importance" sections is a logical thing to do, but I wonder if a left-hand coloured "Importance" column would look better. This also has the advantage that when browsing half-way down a long list, the importance level is still clear.
I will check out some of the existing per-field pages as promised above and report back. Geometry guy 15:50, 14 April 2007 (UTC)
I added a color key for the importance and tried to fix the table width. CMummert · talk 16:42, 14 April 2007 (UTC)
I like it! Meanwhile I've made a first pass through the current G&T page, copying the comments to /Comments pages. Now the second pass, to eliminate any duplication. Geometry guy 18:07, 14 April 2007 (UTC)
Second pass now done... From my point of view the current G&T page could be replaced by the proof of concept. Geometry guy 19:39, 14 April 2007 (UTC)

The plan is for all the field pages to be generated this way, unless there are objections. The argument in favor is that the old pages are horribly out of date and unlikely to be kept in sync manually as the number of rated pages increases. I just used the geometry field as a proof of concept to illustrate what can be done manually. CMummert · talk 21:39, 14 April 2007 (UTC)

I am completely in favour of all field pages being generated this way! However, there may be useful information on the current field pages which is not duplicated in the articles (In the geometry and topology test case, most of the information was duplicated, but I was able to incorporate some additional information into the article talk page in some cases). I think, however, editors interested in other fields should be given the chance to do what I did with G&T for a few days before the new automated scheme is introduced. Do you agree? Geometry guy 22:26, 14 April 2007 (UTC)
The proof of concept looks fine and generating all field pages automatically is an excellent idea. Do I understand it correctly that the comments column in pages like Wikipedia:WikiProject Mathematics/Wikipedia 1.0/Analysis will be overwritten and that we thus lose the entries currently there? If yes, then that worries me. Is that necessary? A few days seems a rather short period. Can't the comments there be transferred to the /comments subpages (e.g., Talk:Manifold/Comments)?
I read an essay some time ago which I can't find anymore. Its main point was that we spend to much time on classifying and rating articles, while we should just be writing and improving them. I don't want to tell others what to do and rating articles is certainly useful, but I do want to raise the issue for you to consider because the essay struck a chord with me. -- Jitse Niesen (talk) 11:37, 15 April 2007 (UTC)
Most of these entries are essentially copies of comments in article talk maths rating templates. I believe a bot should be able to move these to /Comments pages: Salix Alba has created a category to facilitate this process. For the remaining entries, I don't believe moving them to /Comments is easy to automate, so I'm doing it by hand: I've done the work on the Analysis and Geometry and Topology fields so far. (Maybe User:CMummert would be willing to run the code on the Analysis field in another sandbox so we can see where we are so far.) Putting these comments on article talk pages is a useful thing to do anyway, I believe.
I agree entirely with your second point: classifications and comments are a means to an end - improving the quality and coverage of the artices - not an end in themselves: they should make it easy to identify where there is work to be done and what improvements are needed. To this end, they should be easy to update, easy to refer to, and easy to maintain. The present situation, with comments on an article placed by hand in two separate places, wastes editors' time that could be spent writing articles. CMummert's code would solve this. It also contains several other improvements: for instance, both article page and talk page are linked, and there are links to add comments to articles without them. Geometry guy 16:55, 15 April 2007 (UTC)
A proof-of-concept for analysis is at User:CMummert/Sandbox5. CMummert · talk 18:06, 15 April 2007 (UTC)
Thanks! Geometry guy 18:23, 15 April 2007 (UTC)
This is wonderful :-) I've always wanted the rating summary pages to be automatically updated and sorted. The most important thing is that they allow editors to prioritise their efforts (either on important or low-quality articles, accordingy to taste). Migrating the comments to the subpage is a sensible thing. (To be honest, the only reason why I used the "comment" parameter was laziness on my part - it was quicker than creating a subpage, esp. when rating lots of articles). (What would be really nice would be an AWB extension which allows one to rate/categorise an article and post a comment in one click.) So, I think the concept is definately proven. :-) Tompw (talk) 00:28, 17 April 2007 (UTC)
I agree, the concept is certainly proven to me, and there appears to be no disagreement on this now, so I suggest we implement it. I'll start a new subsection below in case further discussion is needed. Geometry guy 12:15, 19 April 2007 (UTC)
I'm planning to work on it this evening. CMummert · talk 13:08, 19 April 2007 (UTC)
Great! I've made a couple of suggestions below. I'll be glad to help out, anyway. Geometry guy 13:44, 19 April 2007 (UTC)

Progress on checking comments on field pages

I believe that all comments on the current Geometry and Topology page are now covered by /Comments pages. If someone wants to check what I have done, that would be very welcome, but from my point of view the current G&T page could be replaced by the proof of concept. Geometry guy 19:39, 14 April 2007 (UTC)

Note that not all comments at Analysis can be found in this proof-of-concept. This is because (I hope) they already exist in article talk page templates, and I've not migrated them to /Comments. As mentioned above, I really hope a bot will be able to do this. Geometry guy 18:23, 15 April 2007 (UTC)

I've now been through Algebra. This was relatively easy, as most of the comments are by Tompw (who almost always makes consistent comments on article and field pages). Geometry guy 19:34, 15 April 2007 (UTC)

I've now also checked Mathematical physics, which was relatively easy for the same reason. Geometry guy 20:21, 15 April 2007 (UTC)

I think we should not include the Mathematicians field in this process until an interested editor comments, as the format there is rather different (mathematicians are organized by year). Anyway, this means the checking is half-done, but I won't be able to do much more for the rest of the week. Geometry guy 22:17, 15 April 2007 (UTC)

In addition to the Mathematicians field, I also notice that there is a Theorems and Conjectures field. In the long term it would be nice to automate both of these, by adding e.g. a "mathematician=year" tag and a "theorem=Y" tag (cf. "vital=Y") to the template. Geometry guy 19:44, 16 April 2007 (UTC)

I've now checked the Basics field page. After automation, I think it makes sense to split Applied into Applied Mathematics and Probability and Statistics. These are, after all, completely different fields. It would also be convenient, I think, to split General into General Mathematics and History. The split pages could be given different names to save checking them for now. Geometry guy 19:44, 16 April 2007 (UTC)

I've now also checked Number theory, Discrete mathematics and Foundations. Subject to the above comments, this completes the checking process. Geometry guy 22:24, 16 April 2007 (UTC)

Thanks for migrating all those comments.
Probability/Statistics is already split from Applied Math in the rating template, it just doesn't have a ratings page like the others. I can easily add the ratings page. Similarly, General and History have different template parameters already.
So the only page that I think needs to be left alone is the mathematicians page. I think the best thing would be to move the old pages to subpages of their respective talk pages, so that they are still available online, and then delete them after a month or so if they are no longer needed.
Does anyone else have any thoughts about this? CMummert · talk 22:55, 16 April 2007 (UTC)

This is a good idea. I would also suggest moving the current "Applied mathematics" page to a (probably temporary) location ("Applied" or "Applied and statistics"). Similarly, the current "General" page could be moved to "General and history". The "Mathematicians" and "Theorems and Corollaries" need further discussion. Geometry guy 23:23, 16 April 2007 (UTC)

I'm sure there was a reason why I put Probability and Statistics on the same page as Applied, but I can't remember it... I think the history category was added as an option after the general page got created. Anyway, seperate rating pages for P&S and history are a good thing. I'll sort it out properly tommorrow morning (it's late, and I'll make silly errors if I do it now) Tompw (talk) 00:31, 17 April 2007 (UTC)

In response to "the best thing would be to move the old pages to subpages of their respective talk pages, so that they are still available online, and then delete them after a month or so if they are no longer needed": Perhaps it's better to have the bot overwrite the pages (I know I'm contradicting my earlier comment). The old versions are forever accessible on the talk page. You can add a link on the talk page to the old revision just to be sure. I don't see much point in moving the old pages to subpages, and very little point deleting them after a month. -- Jitse Niesen (talk) 01:54, 17 April 2007 (UTC)
I went through "General" and "Applied". In all cases but one, the comments were already included in the comment field of the maths rating template, so I didn't do anything. In the remaining case (Theorem, if I remember correctly), I migrated the comments.
So, now somebody has to move the comments from the template to the /Comments subpage. I could write a bot to do that, but I doubt I'll have time to do that soon. One thing I thought of: what happens for pages which fall in several WikiProjects? Should we instead make a /MathsComments subpage? Or should we assume that the comments are shared by all projects? The latter option has my preference (simpler is better), but there might be situations in which that doesn't work well.
Geometry guy, I deleted Category:Mathematics articles with no comments page. For future reference, the easiest way to get a page deleted is to put {{db-author}} on the page. -- Jitse Niesen (talk) 13:48, 17 April 2007 (UTC)

Thanks Jitse! I agree simpler is better. During my edits, the only places I noticed potential conflict with other WikiProjects were two or three articles such as Quantum mechanics which are joint with the Physics project. Even so, I think it is better (as well as simpler) to share comments between projects.

As for the migration of comments to /Comments, there are only about 130 pages to go, and there is no rush, so if we all move a comment from time to time (and I've done quite a few already), it will get done even without the help of a bot. See the categories created above for further information. Geometry guy 19:25, 17 April 2007 (UTC)

Implementation and theorems

There appears to be general agreement that the automatic of per-field ratings pages is a good thing for all fields except "Mathematicians" and "Theorems and Conjectures" (which is not really a field), and that "Probability and statistics" should have its own page, separate from "Applied mathematics". I therefore suggest we begin to implement it. I have a few other ideas as well. Here is a possible list of actions to strike out when done!

  1. Move Geometry and Topology to Geometry and topology.
  2. Similarly move Theorems and Conjectures to Theorems and conjectures.
  3. Choose a consistent title for the field Foundations and mathematical logic aka "Foundations and set theory". Suggestion: Foundations, logic, and set theory. Move the old page to the new name. Fix Wikipedia:WikiProject Mathematics/Wikipedia 1.0/Table accordingly.
  4. Create new page Probability and statistics.
  5. Replace existing field pages by pages automatically generated by CMummert's code:
    Algebra
    Analysis
    Applied mathematics
    Basics
    Discrete mathematics
    Foundations, logic, and set theoryVeblenBot needs to be told the new field name
    Geometry and topology
    General
    Mathematical physics
    Number theory
    Probability and statistics
  6. Write code and run a bot to migrate current inline comments to /Comments page.

I wonder also if it would be useful to add a "theorem" tag the {{maths rating}} template to place articles into a category Category:Mathematics articles about theorems or conjectures (I'm happy to do this and tag the relevant articles). Could this then be used to automatically generate Theorems and conjectures? Geometry guy 13:35, 19 April 2007 (UTC)

I hope you don't mind that I numbered the bullets for easier reference.
Re bullet 3, I disagree - mathematical logic includes more than just set theory.
Re bullet 6, if these have all been done by hand then it is only necessary to remove the inline comment option from the math rating template. I don't think a bot is needed.
Re tagging the articles as theorems, this is already done via Category:Mathematical theorems. It would not be hard to cross reference the contents of that cateogry with the list of rated articles to find the intersection. CMummert · talk 13:53, 19 April 2007 (UTC)
Thanks for adding numbers.
Re 3, you cannot disagree with me :) as I did not express an opinion! I don't mind what the field is called, as long as the same name is used in the title of the page, in links to the page, and in {{WP MATH 1.0}}. However, if I were forced to express an opinion, I would say that, at least to a non-specialist, neither of (mathematical) logic and set theory is a subset of the other, so a more inclusive title would be be Foundations, logic and set theory. I think the word mathematical is unneeded, just as it is unneeded in (mathematical) analysis, because this is a WikiProject Mathematics category, and "mathematical" is understood.
Re 6, alas it has not been done by hand: there are still 131 articles with inline comments. Furthermore, editors continue to add comments using the comment method. Geometry guy 19:19, 19 April 2007 (UTC)

Could you tell again what exactly is to be done with these 131 articles? I would volunteer to handle some of these, if help is needed. Jakob.scholbach 19:37, 19 April 2007 (UTC)

Here is the process. Take an article talk page from Category:Mathematics articles with inline comments (for example, Talk:Abacus) . Remove the comment from the maths rating template and put it in the Comments subpage (for example, Talk:Abacus/Comments). If you can do a few of them, it would certainly help. CMummert · talk 20:49, 19 April 2007 (UTC)
Wikipedia:AutoWikiBrowser can make this process a lot easier. I've created a page at User:Salix alba/Sandbox which lists each page in the category followed by its comments page. You can make a list in AWB with it. Turn off all auto edit functions and make sure skip empty pages is off. The step through the list, cut the comment from the maths rating tag and save, go to the next page paste in the text and save. I manage to do about 30 pages in half an hour with this method. --Salix alba (talk) 23:00, 19 April 2007 (UTC)
The comments appear to be dealt with; check again in an hour or two to make sure the category doesn't repopulate. I edited the template to show an error when inline comments are left. The next thing to do is to make changes 1 through 3 and then wait a while for the job queue to update the articles. CMummert · talk 00:02, 20 April 2007 (UTC)
Very good! Clearly, I should learn to use AWB! Geometry guy 10:28, 20 April 2007 (UTC)

I have now checked that all comments on Wikipedia:WikiProject Mathematics/Wikipedia 1.0/Theorems and conjectures are reflected in the article Comments pages. I've asked the marvellous VeblenBot if it can generate this page for us using Category:Mathematical theorems and Category:Conjectures. Geometry guy 11:16, 26 April 2007 (UTC)

History and mathematicians

I am no longer convinced that a separate Wikipedia:WikiProject Mathematics/Wikipedia 1.0/History page is helpful. At the moment it only contains two articles, and only one is really about history. There is already a WikiProject on the History of Science which rates articles, there is already the Mathematicians field, and I think it is more helpful to place articles like History of manifolds and varieties in the relevant mathematical field ("Geometry and topology" in this case).

One possibility would be to treat these as suggested above for "Theorems and conjecture" using a "history" tag to generate a category called Category:Articles about the development of mathematical concepts or something similar. Comments? Geometry guy 13:41, 19 April 2007 (UTC)

I've now added an experimental "historical" tag to the {{maths rating}} template to put articles in a Category:History of subject mathematics articles (not a great name, I admit). This could be used to autogenerate Wikipedia:WikiProject Mathematics/Wikipedia 1.0/History, while at the same time allowing historical articles to belong to another field. Geometry guy 10:32, 26 April 2007 (UTC)
This has now been used to autogenerate Wikipedia:WikiProject Mathematics/Wikipedia 1.0/History. I find the results very satisfactory! Many thanks again to CMummert. Geometry guy 01:05, 27 April 2007 (UTC)

Finally, does anyone have any ideas for the Mathematicians field? Sorting these by date is the hardest part. Would we be able to do it if every mathematician had a subpage containing their date of birth (or death)? Geometry guy 13:41, 19 April 2007 (UTC)

Although it's a couple of days late: do you mean that you want to be able to sort the mathematicians by date of birth/death? In that case, we actually have a very nice way to do that: persondata. It's special metadata for articles on people which includes (among other things) date of birth/death. Ideally all articles on people should have this, and it ought to be machine readable, so this should solve that issue. Of course, if that's not the issue you meant, then please ignore this. --Sopoforic 00:17, 22 April 2007 (UTC)
The difficulty with that is the bot doesn't download the articles or their talk pages, it only looks at category links and some 'what links here' links. The persondata info is machine readable, but only at the high cost of downloading the article. Putting the info into another subpage, as Geometry guy suggested, wouldn't help. If there is a way to do some crude sorting via categories, that could be made put into the bot. CMummert · talk 02:16, 22 April 2007 (UTC)
I see. It would, of course, be unnecessary to download the article for each update; once to retrieve the info initially and then perhaps monthly (or less often) thereafter would probably be sufficient. It should be possible to do something like this with categories, but that would be at the (very high) expense of manually inserting every article into the category. One ought to be able to put the articles into categories like this: [[Category:Dated mathematicians|1512]], where 1512 is the DOB of the mathematician. Presumably one would be able to extract this ordering from the category page, though not (apparently) the actual sort key used. This may be insufficient for the task at hand--I'm not totally sure what the goal is. --Sopoforic 02:42, 22 April 2007 (UTC)
The best way I see is to use the categories in sequence with Category:19th century mathematicians. This would at least allow sorting by century, so the sort order would be century, then importance, then quality. This is not technically difficult to implement, but the code to do it isn't written. CMummert · talk 02:58, 22 April 2007 (UTC)

Yes, that is what I meant, simply because the current page sorts the mathematicians that way. Sorting by century is one option, but there is the problem that many mathematicians straddle two centuries (e.g. Gaston Darboux and Elie Cartan). There are also Category:1917 deaths style categories, which I suppose in principle could be used, but this may be too complicated to be worth the trouble! Geometry guy 14:12, 22 April 2007 (UTC)

Mathematicians by year: a proposed way forward and some questions

There is now only the mathematicians page left to automate, so I have been looking at it again. There is in fact an obvious way to sort mathematicians by year: just make the table(s) "sortable". This can be automated using /Dates subpages giving the lifetime of the mathematician. Together with a couple of categories, such as Category:BCE mathematians and Category:First millenium mathematicians, sortable tables can easily be produced by transcluding these subpages. Such tables have the additional advantage that the tables can be sorted by importance or quality by clicking on the links provided by the sortable format.

It would be nice to be able to sort the table(s) also by name. One way to do this would be to introduce additional /SortName subpages, which give a sortable form of the mathematicians name (e.g. "Fermat, Pierre de" for Pierre de Fermat).

The creation of /Dates and /SortName subpages from the current page can probably be done using AWB (alas, I still don't have the expertise for this). However, there is another more subtle issue: at present the mathematicians page provides an additional "field" column, which lists the expertise and contributions of a mathematician, in addition to any comments on the quality of the article. This can partially be covered by the /Comments subpage. However, I think it might be useful to transclude another page containing the expertise and contribution information.

Many of these list entries describe the field(s) in which the mathematician contributed. This makes me wonder whether we should replace the "field = mathematicians" tag by a "mathematician = yes" tag, so the field is still free (for the primary field in which the mathematician contributed). One advantage of this would be the possibility to sort mathematicians by field. The mathematicians could then also be listed on the relevant field pages, although it is not obvious that this is necessarily a good thing, so please add comments! Geometry guy 19:47, 27 April 2007 (UTC)

Proof of concept for mathematicians

To show how this can be done, User:Geometry guy/Mathematicians Wikipedia:WikiProject Mathematics/Wikipedia 1.0/Mathematicians now contains a sortable list of mathematicians with some dates. Most of the content of this page was automatically generated by VeblenBot with no change to the code. There are links for adding /Dates, /SortName, and /Contribs subpages to mathematician talk pages. At the moment, the sort order for the "class" and "importance" columns is not the natural one. Also, BCE and first millenium dates do not sort correctly. Feel free to make comments, changes, or add dates etc. Geometry guy 12:32, 28 April 2007 (UTC)

I've now added almost all the dates, and many sortable names to the table. I have also managed to make the class and importance columns sort naturally, as well as BCE and first millenium dates, although my solutions are not particularly elegant. Geometry guy 18:17, 29 April 2007 (UTC)

Apologies for not getting back sooner. The /Mathematicians table is nice, its certainly fun to be able to sort by dates class etc. I'm a little unsure about the /Dates, /SortName, and /Contribs sub pages, a perfusion of sub pages seems a bit excessive.
An alternatives is to use a database type structure to store the data. I've done a sort of database for the properties of polynomial at Template talk:Polyhedra DB, quite esoteric as its pre-parser function and could be much nice using a switch.
There are two ways this could be done, as one big page with the data for all mathematicians. Or with a sub-page per mathematician say /DB, this latter could be like
{{#switch:{{{key}}}|date=1970|sortName=Pascal, Blaise}}
this would save in creating too many extra pages and could be extensible.
One thing I've been doing on a separate wiki [41] is treating each wikipage as a object which has properties which are stored in a seperate table in the database. In the page, say in [[Pascal]] you can use {{#setProperty|date|1970}} to set a property, an extracted anywhere using {{#getProperty|Pascal|date}}. This is of course just wishful thinking as getting this implemented in wikipedia would be a task.
This might be a little too late to change things as I see you done a lot of good work creating the sub-pages, so we might as well stick to that style. --Salix alba (talk) 08:34, 30 April 2007 (UTC)

I agree that the profusion of subpages is not ideal and your ideas are interesting indeed. I think the data should be stored with each mathematician, but I am not wedded to the current (experimental) approach. The /DB subpage per mathematician is a nice idea, and it might not be too much work to migrate the data I have created to produce entries like

{{#switch:{{{key}}}|dates= Talk:Johannes Kepler/Dates |sortname= Talk:Johannes Kepler/SortName|contribs= Talk:Johannes Kepler/Contribs}}

(This above was generated by a template User:Geometry guy/MakeDB which might make the migration easier.) [Note added: I am now substituting for this template, so I can delete it from my user space.]

As I understand, I then just have to modify Wikipedia:WikiProject Mathematics/Wikipedia 1.0/Mathematician row format template to replace transclusions like {{ {{{1}}}/Dates }} by {{ {{{1}}}/DB | key = dates }}, which is easy to do. Geometry guy 09:48, 30 April 2007 (UTC)

The mathematicians page has now been fully automated by CMummert and VeblenBot. However, in view of the above discussion, it may be subject to some change for a short period. Geometry guy 16:38, 30 April 2007 (UTC)

I have now copied the /SortName, /Dates and /Contribs subpages into /Data subpages of the form

{{#switch:{{{key}}}|dates = 1872 – 1984 |sortname=Guy, Geometry|contribs = Geometry, mostly}}

and modified the templates to use these /Data subpages in the Mathematicians table. The only disadvantage of this approach is that the /Data subpages appear to be empty. This could be fixed by adding instructions inside a "noinclude". I could do that, but it will take a while, even using AWB. Geometry guy 16:48, 3 May 2007 (UTC)

I've had a play about with Talk:René Descartes/Data and a template in my sandbox {{User:Salix alba/Sandbox}}:
  • {{Talk:René Descartes/Data|key=dates}} gives: 1596 – 1650
  • {{Talk:René Descartes/Data|key=sortname}} gives: Descartes, René
  • {{Talk:René Descartes/Data|key=contribs}} gives: Geometry: analytic geometry
  • {{Talk:René Descartes/Data}} gives: This subpage contains data about WikiProject Mathematics which is used by the Wikipedia:WikiProject Mathematics to produce tables of mathematicians. Edit this page to add or update the sortable name (sortname), date of birth or death (dates) and field (contribs) of WikiProject Mathematics.

  • Name: Descartes, René
  • Dates: 1596 – 1650
  • Contribs: Geometry: analytic geometry
Basically whats happening is I've changed Talk:René Descartes/Data to be
{{User:Salix alba/Sandbox|{{{key}}} | dates= 1596 – 1650 | sortname= Descartes, René | contribs= [[Wikipedia:WikiProject Mathematics/Wikipedia 1.0/Geometry and topology|Geometry]]: analytic geometry}}
with a template name instead of the switch. The key parameter to Descartes/Data is passed through to the second template. This is just a switch, but with a default argument which prints out the data in human readable form. if a parameter is given it just behaves as if the switch was there, no parameter, ie when viewing the /Data page you get the human readable form. --Salix alba (talk) 23:46, 3 May 2 007 (UTC)

Nice! Can you implement this? I know it is boring going through 147 articles with AWB, but I think it is worthwhile. Using a template as you suggest has the huge advantage (which I didn't appreciate when I created these /Data pages) that the format can be changed without having to change all the pages. For the same reason, it is probably worth being flexible about any "noinclude": I was going to transclude a template explaining how to edit these pages, but it might be possible to absorb this into your idea. Geometry guy 00:13, 4 May 2007 (UTC)

Geometry and topology is now live

Please look at Wikipedia:WikiProject Mathematics/Wikipedia 1.0/Geometry and topology, which is a test example of how to use the automated tables. Before implementing the other fields, I want to collect feedback on this one. It's worth looking at the source of that page to see how the implementation works. CMummert · talk 15:21, 20 April 2007 (UTC)

Perfect! I might slightly adjusts the column width. Links to the other field pages at the top could be helpful. --Salix alba (talk) 16:37, 20 April 2007 (UTC)
Still looking good! Maybe it is worth explaining in the lead how to Add or update Comments by following the handy links. Geometry guy 18:11, 20 April 2007 (UTC)
Looks good to me :-) Could we have {{WP MATH 1.0}} at the bottom? Tompw (talk) 18:30, 20 April 2007 (UTC)

It isn't obvious without looking at the page source code, but that page can be edited by anyone and the changes will not be lost. The tables themselves are included from another page, and changes to them will get overwritten. So it's possible to edit the lead section or add stuff to the bottom without having to ask me to edit the bot code. Tompw has suggested a way of formatting the tables so that the formatting will also be able to be tweaked from the wiki without changing the bot. CMummert · talk 20:06, 20 April 2007 (UTC)

(For the record, I suggested a template... it's at User:Tompw/sandbox12 currently, and is being trialed at User:CMummert/Sandbox5. Tompw (talk) 12:29, 21 April 2007 (UTC))
This looks really nice, but I have a small request. Having every comment field starting with 'Comments:' is a bit distracting, so is there any way we can do something like:
Consider re-nominating for Featured Article status. Tompw 12:25, 6 October 2006 (UTC) (edit comments)
I think the same link code could be used for articles with and without comments too. Cheers, darkliight[πalk] 09:50, 21 April 2007 (UTC)
Like this? Tompw (talk) 12:29, 21 April 2007 (UTC)
Yeah I think thats much better. Is there any reason not to use the url that sends people straight to the edit page though? darkliight[πalk] 13:42, 21 April 2007 (UTC)
Yes, there is... if you have an article with spaces in the name, you end up with an edit link like: coordinate system/Comments&action=edit (see source). Tompw (talk) 14:07, 21 April 2007 (UTC)
Ahh I see, no problem then, and thanks. darkliight[πalk] 14:25, 21 April 2007 (UTC)
Can we find a work-around for this? Is there a method for replacing spaces by underscores? Geometry guy 22:13, 21 April 2007 (UTC)
Since anyone can edit the format I see no reason not to roll out the entire list. However, I have one more suggestion: these pages are probably all going to have essentially the same format, so why not have a single page or template describing this format, which can be included in each of the field pages. I've done this with Wikipedia:WikiProject Mathematics/Wikipedia 1.0/General so you can see what I mean. The format is defined at Wikipedia:WikiProject Mathematics/Wikipedia 1.0/Field page format. This makes it trivial to roll out the remaining pages. Geometry guy 13:55, 21 April 2007 (UTC)
That's a good idea. Tompw (talk) 14:07, 21 April 2007 (UTC)
I changed the bot to use a template to format the table rows and hacked with the template to make them get along. You can see the results at Wikipedia:WikiProject Mathematics/Wikipedia 1.0/General. CMummert · talk 20:38, 21 April 2007 (UTC)
I bashed the template some more, and it all seems to be working OK :-). Are we ready to roll this out across the board?Tompw (talk) 21:12, 21 April 2007 (UTC)
The template I made was just a primitive first attempt: feel free to alter it radically! Anyway, this should be easy to do, and everything else seems to be well, so I will roll out the other fields. Geometry guy 22:13, 21 April 2007 (UTC)
I made the changes necessary because of the new name for the logic field, and updated the tables. That takes care of all the bullets above. There is still the remaining issue of a new "Theorems" field page, which could be automatically generated as well. That will take some time to implement. I want to say that the transition process went much more smoothly than I had anticipated because of Geometry guy, Salix Alba, Tompw, and others taking care of important parts of the work. CMummert · talk 23:59, 21 April 2007 (UTC)
That's the beauty of wikipedia! The response to my puzzled query has been fantastic, and with a great outcome. If I were in to barnstars and such things, I'd be awarding them to everyone involved, especially CMummert! Geometry guy 14:25, 22 April 2007 (UTC)

Category:Mathematicians by religion nominated for deletion

Category:Mathematicians by religion nominated for deletion before I could get to doing it. (Ask me about Slovenia!) Please go comment at Wikipedia:Categories for discussion/Log/2007 April 29. Dr. Submillimeter 22:49, 29 April 2007 (UTC)

Automated archiving

I have edited the source of this page to ask User:MiszaBot II to automatically archive it. If any errors occur, please remove the template from the very top of this page's source code. The cutoff is currently set for 7 days, and the bot appears to run at 6:35 and 18:35 UTC each day. CMummert · talk 13:33, 30 April 2007 (UTC)

Cultural comment

I added this comment to FOIL rule:

This mnemonic is not used by mathematicians and perhaps not known by most mathematicians, but is taught by secondary school teachers.

I took every math course my high school offered; the curriculum was better than at most high schools and I not only mastered calculus when I took the course but absorbed a lot of material beyond what was required in every course, and I NEVER heard of "FOIL" until as an undergraduate I was tutoring other undergraduates. It seems this mnemonic is completely universally known to everyone who hates algebra but is required to take an algebra course. Am I right to think that perhaps most mathematicians don't know it? Michael Hardy 17:39, 30 April 2007 (UTC)

Pardon me while I retch. An apt commentary is
Rote has its place, as in learning to add and multiply single digits. But in the case of this mnemonic, whoever is teaching the teachers should be taught better. --KSmrqT 19:02, 30 April 2007 (UTC)
(edit conflict) Perhaps this is a generational thing (although I make no supposition about how old Michael Hardy is).  :) I grew up with this terminology as did most of my peers (currently or recently in grad school). It is often used as a verb, and in fact, its use has extended beyond even multipling two binomials together. Although technically incorrect, one might say, "Foil these terms together" when referring to multiplication of any polynomials, the idea being that you extend the idea of "FOIL" in a natural way to more terms. I'm not saying this should be mentioned in Wikipedia, but it is widely known among people I know. VectorPosse 19:06, 30 April 2007 (UTC)
I would definitely say it should be exposed in Wikipedia, along with other silly rotes that every recent high school graduate seems to know. I would even go as far as suggest a category: silly rotes (mathematics). As for generational thing, VectorPosse is probably right. It would be actually be interesting to pinpoint the origin of some of these widely known rules. On a side note, I pity the generation that had to grow up with things like that, as opposed to, let's say, Martin Gardner's amazing books and columns. Arcfrk 19:23, 30 April 2007 (UTC)
Teaching students this age is a challenge, and we should support — not ridicule — the teachers. Not all mnemonics are bad, and different students respond better to different means. Should we lampoon "SOH CAH TOA"? How about "xyzzy"? Pity the poor astronomy student who must remember star classifications. --KSmrqT 19:55, 30 April 2007 (UTC)
Teaching in any age is a challenge, and one may choose whether to rise to the challenge, to supplement teaching with entertainment, or to dispose of the substance entirely. Far from ridiculing teachers, categorizing silly rotes is a first step to correcting the incalulable damage that they inflict on students of mathematics (yes, I said damage, and I mean it). If you want an amusing 'advanced' rhyme (which no one takes seriously, by the way), how about
Гомоморфный образ группы,
будь, во имя коммунизма,
изоморфен факторгруппе
по ядру гомоморфизма!
This is a poeticized form of the first isomorphism theorem widely known in Russia Arcfrk 20:16, 30 April 2007 (UTC)
Hmm; I think that second line will have to change for the English-speaking world. ;-) --KSmrqT 20:59, 30 April 2007 (UTC)
I'm confused. What is this rule even about? Some weird kind of algebra with a non-commutative addition where one needs to remember the order in which the terms of the folded-out product comes? I fail to imagine a distributive law that could feel halfway natural and still dictate an internal order between the O and I terms. –Henning Makholm 20:25, 30 April 2007 (UTC)
Hypnotize yourself and regress back to a time in your life when words like "commutative" and "distributive" meant nothing to you. The order of the terms in FOIL is irrelevant; the point of the mnemonic is to help students remember the four terms of the result. Apparently their brains would explode if asked to understand and use the distributive law twice, especially since the pieces are not numbers but symbolic monomials. --KSmrqT 20:54, 30 April 2007 (UTC)

I don't understand all the fuss.

The statement, "This mnemonic is not used by mathematicians and perhaps not known by most mathematicians, but is taught by secondary school teachers" seems a little strong. Why not just say "This mnemonic is often taught in secondary schools" and leave it at that? In the article it also says, "The FOIL mnemonic is commonly taught but is sometimes frowned upon because the method does not work, without modification, for higher order polynomials (the double distributive method, by contrast, is easily extended to the latter case). Foiling can thus be seen as an example of learning by rote memorization of rules rather than by understanding underlying concepts." But I always have to memorize base cases, and I can combine FOIL with recursion to expand the multiplication of sums of arbitrary terms.

I disliked the article on purplemath.com referenced above. It's primarily because the author adopts the tone of "this is the way I do it so this is correct and it is the way you should do it." I'd agree more with KSmq's second comment that "Not all mnemonics are bad, and different students respond better to different means." (I also have a strong distaste for the use of "simplify" to describe the process of expanding the multiplication. Yuck.)

IMHO, the "Factorization" section of the article should either be removed or modified. It's not at all clear how one FOILs in reverse.

My two cents, Lunch 20:37, 30 April 2007 (UTC)

Everything should be taken off the page that is not reliably sourced. I suspect this is US-oriented remedial material. Charles Matthews 21:12, 30 April 2007 (UTC)
On the talk page, Taxman commented in 2005 that "the phrase could certainly use some attribution to a reputable source, and I haven't been able to locate one." A web search for 'FOIL polynomial' brings up a plethora of supporting hits, so there is no question that this name is used for this topic. I suspect it is not just remedial, as educational standards for mathematics lack the Cold War motivation of Sputnik and the beneficial influence of an influx of educated immigrants fleeing Nazi purges. --KSmrqT 21:30, 30 April 2007 (UTC)
(edit conflict, again.) About removing unsourced material, yes. About being US-oriented, I suppose so if someone from Europe says so. About remedial, no. It is, as I mentioned above, at least for people in my generation, common parlance. The points about rote learning are well-taken, but ultimately irrelevant to the article in question. In my calculus classes, I refer to it simply because "foiling" is easy to say and understood by everyone present. The article probably can be sourced, but I just want to point out that this term has widespread usage even apart from any pedagogical considerations. VectorPosse 21:33, 30 April 2007 (UTC)
My impression is that many textbooks discuss FOIL, but I don't have a stack of them handy. However, Steege & Bailey, Schaum's Outline of Intermediate Algebra, 1997, ISBN 978-0-07-060839-9, is searchable at Amazon.com; perhaps it will suffice for now. One can also find several discussions like this and this critique at "The Math Forum". --KSmrqT 22:53, 30 April 2007 (UTC)
PS: Further discussion specific to FOIL should probably move to the article talk page. --KSmrqT 22:55, 30 April 2007 (UTC)

Unital ring poll

There is an ongoing opinion poll at Talk:Ring (mathematics)#Poll on unit requirement as to whether or not the rings on Wikipedia should be defined to unital or not. Opinions welcome. -- Fropuff 04:22, 1 May 2007 (UTC)

May 2007

This is the archive file "Wikipedia talk:WikiProject Mathematics/Archive 25". It is for May 2007.


Dispersive PDE wiki

The dispersive partial differential equation wiki now has the gnu free documentation license listed as its copyright, which I think means that stuff from it can now be copied over into wikipedia (which seems to use the same license, though someone who knows about these things should confirm this). Maybe someone who knows about these thinks could make a template to say something like

This article incorporates material from ... from the dispersive PDE wiki, which is licensed under the GFDL

R.e.b. 21:18, 2 May 2007 (UTC)

Curves (disambiguation)

Theres been a dispute over whether Curves (disambiguation) and Curve (disambiguation) should be merged, which has now gone to RFC. So I though I'd invite the heavy mob over to Talk:Curves (disambiguation). --Salix alba (talk) 21:31, 2 May 2007 (UTC)

Georg Cantor

The tedious arguments at Georg Cantor over whether the great man was Jewish will simply not go away. Myself, I don't much care, except of course I want our information to be accurate, encyclopedic, and not confusing, even on fairly tangential points. If some editors here (especially, if such there be, ones with good knowledge about history) would help find a resolution, maybe we could get back to the serious business of crackpots who think they've refuted the diagonal argument.

My thoughts on the matter are summarized at talk:Georg Cantor#Edit wars over Jewishness or otherwise. --Trovatore 20:16, 29 April 2007 (UTC)

The problem here is:
  • Cantor's grandfather, possibly also his grandmother, seem to have be born, or been by descent Jewish. His father and himself were deeply religious Lutherans; his mother Roman Catholic.
  • Under these circumstances, he himself is not Jewish; "neither in an orthodox rabbinical sense, since his mother was Roman Catholic, nor in the sense of a practiced faith", as one authority says.
  • Should the article have the Template:Cat:Jewish mathematician? The cat does allow for Jewishness by descent, but this is intended to cover cases like Einstein: unorthodox, unbelieving, or converted Jews.
  • There must be a limit to how tenuous descent must be to count; otherwise we get like the helpful soul who catted Robert E. Lee as Scottish-American. (The Lees are thoroughly English, but claim descent from Robert the Bruce.)
This is a matter of definition, not of history, and I have no opinion on it. Septentrionalis PMAnderson 03:35, 3 May 2007 (UTC)
Unless he went out of his way to practice Judaism or to associate himself with Jews (which he did not as far as I know), then he should not be labeled as Jewish. Otherwise, we are adopting the pernicious idea that the Jews are a race (shades of Julius Streicher). JRSpriggs 07:04, 3 May 2007 (UTC)

Layout question

This is probably a stupid question, but how can I avoid the following layout problem (without taking the separated formula in the text body, of course):

H*(X, F)

are finitely generated.

  • next point


(I don't want the "are finitely generated" to start at the beginning of the line, but aligned with the text "On a proj..." and "next point"). Thanks Jakob.scholbach 18:48, 5 May 2007 (UTC)

I usually just put a colon at the beginning of the successive lines. This doesn't work perfectly but it's more aesthetic. I too have wondered if there's a real solution. Ryan Reich 18:55, 5 May 2007 (UTC)


Perhaps there is a better answer to this annoying behavior, but one dodge is to use HTML markup instead of wikiness, like so:

<ul><li>On a projective complex manifold ''X'', [[sheaf cohomology|cohomology]] groups of [[coherent sheaves]] ''F'',

<dl><dd>''H''<sup>&lowast;</sup>(''X'', ''F''),</dd></dl>

are finitely generated.</li>

<li>next point</li>

</ul>



And please, stop using quote-quote ('') as if it were TeX's math markup ($). If you want italic variables, italicize only the variables — not the parentheses nor the numerals nor anything else that gets in the way. (Fixed in my example.) Also, you may wish to consider using HTML &lowast; instead of an asterisk, as I have done. --KSmrqT 19:35, 5 May 2007 (UTC)

"7 unsolved problems"?

This is sort of frivolous, but I didn't want to make any changes to such a contentious topic. Now that the Poincare conjecture is proven, and its proof is verified three ways from last August, shouldn't the "did you know..." factoid about the Millennium Prize problems read "there are 6 unsolved problems..."? Ryan Reich 23:42, 5 May 2007 (UTC)

Though to answer my own question, there is a pretty good argument that we should wait for the Clay Mathematics Institute to make it official. Ryan Reich 23:44, 5 May 2007 (UTC)

dashes in page titles

Recently an editor changes Poincaré–Birkhoff–Witt theorem to a redirect to Poincaré-Birkhoff-Witt theorem (the former uses en dashes, the latter hyphens) although it was quickly reverted. I know some of the math folk here have impressed upon others in the past that the en dashes are correct and should be used in the page title. WP:MOSDASH agrees that using the en dashes is correct (since these are different people's names) but states that for page titles simple hyphens should be used. A provision that it is ok to redirect to the dash title from the hyphen title has been struck out. After some investigation, it's clear that a discussion on the WP:MOSDASH talk page is what led to the previously mentioned edit; the discussion seems to have pinpointed a problem with saving pages with dash titles on computers using an older version of Internet Explorer. --C S (Talk) 06:54, 30 April 2007 (UTC)

What a silly thing for people to be worried about, exactly which dash belongs where. As far as I'm concerned there should only be one dash (the one on my keyboard) to avoid all the confusion. StuRat 16:43, 30 April 2007 (UTC)
Part of the point is that the different dashes have different meanings. If one writes about the Chan-Ho-StuRat theorem, one doesn't know whether it's a result by three people named Chan, Ho, and StuRat, two people named Chan and Ho-Sturat, etc., whereas if one writes about the Chan-Ho–StuRat theorem the distinction is more clear to those paying attention. So within the text of an article, using the right kind of dash can be important. As for titles of articles, I find the argument on MOSDASH unconvincing, especially because both names should be present with a redirect from one and the character appearing in the url will depend on which path one uses to reach the article, but whatever. —David Eppstein 16:55, 30 April 2007 (UTC)

Part of the problem with the guidelines is that the current practice is in flux. It appears to me that two years ago almost all titles were in ASCII, but now there is a definite trend for arbitrary Unicode characters in titles. So long as all useful redirects are in place, the actual title doesn't matter too much. CMummert · talk 17:06, 30 April 2007 (UTC)

The problem is that you can't save a page by saving a redirect! So, from the point of view of good typography and clarity, it is better to have Chan-Ho-StuRat theorem redirect to Chan-Ho–StuRat theorem, but from the point of view of everyone being able to save content, it is better to have Chan-Ho–StuRat theorem redirect to Chan-Ho-StuRat theorem. I agree the trend is towards unicode, so WP probably needs to introduce an error message like "You are using a badly designed operating system and/or browser. Please update your computer to use non-Microsoft products" for this situation. Incidently, Chan-Ho–StuRat theorem is still a redlink: is anyone going to make a stub? It could be a nice result ;) Geometry guy 17:19, 30 April 2007 (UTC)
WP:BEANS.  ;) --C S (Talk) 07:39, 7 May 2007 (UTC)

GA Review

The following articles are up for GA Review, feel free to comment.

Hope to see you there. 74.116.113.241 01:18, 8 May 2007 (UTC)

Mathematics article assessment

Thanks to the efforts of several editors, the assessment of mathematics articles using the {{maths rating}} template is now considerably more useful and worthwhile than it was before. I thought it would therefore be helpful to summarize the current system and its benefits, and to encourage editors to add ratings to existing and new articles.

The maths rating is a template which can be placed (by anyone) on the talk page of any mathematical article to summarize its quality, importance and field, and suggest improvements that could be made.

What can article assessment do for you? The maths rating system is useful for directing our efforts towards improving the mathematics coverage of wikipedia. It also helps us to monitor the progress of this WikiProject. Although assessment is a means to an end, rather than an end in itself, it is a useful way to organize and monitor our efforts.

Recent improvements to the system mean that articles with maths ratings are now included automatically (with comments) in many useful tables. For instance, you can see the ratings for articles in your field (e.g. algebra), you can find stub class articles (listed by importance) to improve, or articles considered to be vital to the project rated by importance and quality. Rated articles about mathematicians are listed in a sortable table and there are also tables of theorems and conjectures and historical articles, sortable by field. All rated articles are listed in these tables (which are updated daily). They are also automatically included in a a hierarchy of categories. Every table or category has a navigation bar that links easily to any other.

What can you do for article assessment? There are many ways we can all improve this scheme to maximize its benefits.

  • Add the {{maths rating}} template to the talk page of an article. For example, when creating a new stub, why not also start up the talk page with a maths rating?
  • Add or update data in {{maths rating}} templates. There are may articles whose importance or quality is unassessed. Take a quick look at the assessment scheme and assess or reassess an article today!
  • Add comments to an article with a maths rating. There is a whole category of mathematics articles which have no comments. A signed comment helps even just to date the maths rating, but even better, it can provide a summary of suggested improvements for the article that other editors can read.
  • Add extra information about mathematicians. To make sortable tables, the dates, surnames, and primary fields of mathematicians are needed. It is too difficult to deduce these from page contents, so they are stored in a special format. Just click on the links in the mathematicians table to add or update these data.

Finally, you can contribute by making suggestions here or at Wikipedia:WikiProject Mathematics/Wikipedia 1.0 on how the scheme can be improved further. Many thanks. Geometry guy 01:39, 9 May 2007 (UTC)

The initial sentence in "probability distribution" is terrible!!

Here it is:

In probability theory, a probability distribution is a function of the probabilities of a mutually exclusive set of events.

That is idiotic nonsense. I had no idea this article was in such profoundly bad shape. I'm going to have to think about how to rephrase this. If someone beats me to it, I will be pleased. Michael Hardy 17:25, 7 May 2007 (UTC)

... OK, now I've changed it. I was shocked by what I read. Michael Hardy 17:33, 7 May 2007 (UTC)
Is it standard that the term "distribution" is restricted to measures over subsets of the real numbers, rather than the general case of measures over subsets of any possible space of outcomes (e.g., random curves)?  --LambiamTalk 18:19, 7 May 2007 (UTC)
The Encyclopaedia of Mathematics considers a probability distribution to be any probability measure of a probability space.[42]  --LambiamTalk 18:27, 7 May 2007 (UTC)
I'm not sure what's standard, but my old copy of Feller's book says that distribution functions are "non-decreasing functions which tend to zero as x → −∞ and to 1 as x → ∞." That seems to imply that a distribution function is defined in terms of a random variable that can only assume real values. On the other hand, I only have vol. 1 of An Introduction to Probability Theory and Its Applications. DavidCBryant 18:48, 8 May 2007 (UTC)

Well, of course obviously there are vector-valued random variables, and permutation-valued random variables, etc. etc. etc. I've now modified the first sentence accordingly. Michael Hardy 20:56, 8 May 2007 (UTC)

My impression was that "distribution" refers to something more complicated than a density function, but not as complicated as a measure. You use it with the Riemann-Stieltjes integral#Application to probability theory. JRSpriggs 06:22, 10 May 2007 (UTC)

Template:Numerical algorithms

The {{Numerical algorithms}} template appears to me as a rather indiscriminate collection of numerical algorithms, with a heavy bias towards root-finding algorithms. I don't know if it is necessary, and if it is, if grouping these together is any good. For example, it is of little use at Pseudorandom number generator and Fast Fourier transform. I would argue that it should be either thoroughly rewritten and posted on a different collection of articles, or otherwise deleted. Comments? Oleg Alexandrov (talk) 19:56, 12 May 2007 (UTC)

I agree that this navigation bar is useless (unbalanced, incomplete, and also inaccurate). That might, perhaps, be fixed, but in this case I don't understand what aim it could achieve that is not much better addressed by categories (for navigation) and a good overview at Numerical analysis.  --LambiamTalk 21:10, 12 May 2007 (UTC)
The obvious thing to do (and probably the least work) would be to move the template to "root-finding algorithms" and remove all the other stuff. Geometry guy 21:38, 12 May 2007 (UTC)
Having looked at it, my first instinct is to delete it as a useless eyesore. While deleting from each article, add a category as Lambiam suggests. --KSmrqT 21:43, 12 May 2007 (UTC)
OK. Jitse, our numerical guy, agrees too (on his talk page). I removed it from articles and deleted it. Oleg Alexandrov (talk) 15:39, 13 May 2007 (UTC)

As yet to be added mathematics articles

In my quest to assess every mathematics article I came across several articles that were in the purview of this Wikiproject that had not been placed under its supervision. This troubled me and I would like to know what can be done to add these articles to our project efficiently. The articles I have found thus far are Mandelbrot set and Lorenz attractor but I am sure there are more out there.--Cronholm144 18:52, 12 May 2007 (UTC)

You mean, articles without the Project Math banner on their talk pages? Just do what you did to Mandelbrot set, add one there. Also, add a mathematical category (e.g. Category:Fractals) to the article itself if it should have one and doesn't. —David Eppstein 19:02,