User talk:David Eppstein

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Hi, and welcome to my User Talk page! For new discussions, I prefer you add your comments at the very bottom and use a section heading (e.g., by using the "New section" tab at the top of this page). I will respond on this page unless specifically requested otherwise.

Layered graph drawing[edit]

Dear David Epstain, I'm a PhD candidate in Anthropology at University of Verona, Italy. In my research I use some Social Network Analysis and Visuazlization and I have found out a circular layered layout, written for gephi ( by Jaroslav Kuchař (Information Technology, Czech Technical University di Praga). Here is the code address ( and the plugin address ( I believe insert information about this plugin could enhance the wiki page, but I am not enough technically skilled to write about it with the same level of expertise you had in the page (and I don't have the time right now to study it more). So, I just wanted to inform you about this layout, it might interest you. Thanks for the page. Miromarchi (talk) 09:56, 3 April 2015 (UTC)

Requesting your opinion on programming language article[edit]

I was wondering if you might consider commenting on this AfD Wikipedia:Articles for deletion/Nim (programming language) as a professor of computer science and an administrator. I would appreciate your expert opinion on this matter, whichever side you take. ― Padenton|   23:12, 4 April 2015 (UTC)

Binary Number[edit]

Question regarding your revert of my contribution to the Binary Number article. It is my understanding that Pingala's theory predates those documented in the article. I therefore ask why the point regarding Pingala's system has been deleted? I am of the opinion that the historical section within this article should be written in chronological form. As you mentioned in your summary of the deletion, the facts are correct and the content is relevant, which is why I am a little confused by the revert. I totally appreciate the fact that you are an expert at an academic institution, which is why I have taken such a subtle approach to reach out (just in case I have misunderstood something). I look forward to working with you. -JG (talk) 11:02, 9 April 2015 (UTC)

Pingala does not predate the ancient Egyptian uses of binary-like numbering systems (for Eye of Horus fractions, and for integer multiplication). —David Eppstein (talk) 15:35, 9 April 2015 (UTC)
Thank you for your response sir - much appreciated. I would argue, with all due respect, that your point is debatable in the context of the "History of Binary". All historical overviews should, in my humble opinion, include Pingala. When was the Egyptian version published?

I look forward to working with you. -JG (talk) 17:03, 9 April 2015 (UTC)

The binary Eye of Horus fraction system (superseded by the later Egyptian fraction system) is documented by the Akhmim wooden tablets, circa 1950 BC. The multiplication algorithm is documented by the Rhind Mathematical Papyrus, circa 1650 BC. Both are well over a millenium before Pingala. —David Eppstein (talk) 17:20, 9 April 2015 (UTC)
Thank you for your response. These texts appear to be quite far and much broader than the actual binary process of 0 & 1's, which is the subject of the article. I can similarly argue the work of Aryabhata, Brahmagupta, Mahāvīra, Bhaskara II, Madhava of Sangamagrama and Nilakantha Somayaji in a similar way. I would still want Pingala to be in this article. The argument for it to be omitted is not making sense. Let me know if I am mistaken. also let me know where you would recommend it to be if not the history section. it is such a prominent piece to be left out.

-JG (talk) 18:28, 9 April 2015 (UTC)

I am not arguing for it to be omitted. I am arguing that the way you added it is wrong in at least three ways: (1) you put it at the front of the section instead of in the paragraph about historical predecessors of binary, (2) you claimed that Pingala invented the binary number system, when in fact he used a binary notation for something other than numbers, and (3) you claimed that he was the first to use a binary system, when in fact the Egyptians did so much earlier. In short, it came off as ahistorical and jingoistic.
Incidentally, the Chinese also had a system of binary notation (for things other than numbers) that most likely predated Pingala (dating to between 1000 and 400 BC): the I Ching. —David Eppstein (talk) 18:40, 9 April 2015 (UTC)
It was my assumption that the section documented binary has a holistic subject, which is how the article reads in my opinion. I would suggest that being branded a jingoist or even having an ahistorical perspective isn't a fair call in this case. That said, I will rework the paragraph and title it "historical predecessors of binary". Please suggest where it would best fit.

I am not from India BTW... British to the bone. -JG (talk) 15:43, 10 April 2015 (UTC)

You're invited to a meetup[edit]

You are invited to join the discussion at Wikipedia:Meetup/San Diego/April 2015. Thanks. RightCowLeftCoast (talk) 18:39, 10 April 2015 (UTC)


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Reaper Eternal (talk) 15:33, 12 April 2015 (UTC)

Salted article back under new title[edit]

Hi, regarding Wikipedia:Articles for deletion/Asif Ali Lighari which you closed, see Asif Lighari. I'm not sure if it is substantively different enough not to be a G4, so I bring it to you for your evaluation. Thanks, CrowCaw 23:34, 12 April 2015 (UTC)

Thanks for brining this to my attention. That was actually the third AfD for this article under three different variants of the name; all were deletes. I've deleted and salted this one too; the third was a snow close so no point in making a fourth AfD. Additionally, the creators of these articles probably should be blocked as sockpuppets of Princeneil. —David Eppstein (talk) 23:39, 12 April 2015 (UTC)
  • Thanks! I can no longer see those authors, so can't do the SPI though. I'll keep it on the list for future alerts though. CrowCaw 00:01, 13 April 2015 (UTC)
  • I already blocked them and tagged them as suspected socks. I think the evidence is clear enough that there's no point running it through the SPI (they pass the duck test so we likely cannot persuade the checkusers to run a check). —David Eppstein (talk) 00:09, 13 April 2015 (UTC)

Thomas James Power listed at Redirects for discussion[edit]


An editor has asked for a discussion to address the redirect Thomas James Power. Since you had some involvement with the Thomas James Power redirect, you might want to participate in the redirect discussion if you have not already done so. Big_iron (talk) 14:05, 19 April 2015 (UTC)

Facet (geometry)[edit]

Hi David, you recently edited the disambiguation page Facet (geometry). I have commented on this at Talk:Facet (geometry)#Faceting and facets and would appreciate your feedback there. — Cheers, Steelpillow (Talk) 10:03, 21 April 2015 (UTC)

Tau redirect[edit]

Hi. I'm helloholabonjournihaonamasetgutentag. I noticed that you made the Tau (mathematical constant) page into a redirect into Pi. Why? I think that Tau should have its own page as more and more people are using it. Please check out [this video]. Thanks for considering! Helloholabonjournihaonamastegutentag (talk) 15:44, 23 April 2015 (UTC)

Because this has been discussed to death at Talk:Pi and Wikipedia:Articles for deletion/Tau (mathematics) and I didn't see any evidence that whoever created the new article had paid any attention to those discussions or brought anything new to them. —David Eppstein (talk) 17:23, 23 April 2015 (UTC)
I created that article. I understand that Pi is much more commonly used, but Tau has many advantages. Even if you prefer Pi, which is fine and is your choice, don't you think that Tau should at least have its own article? It seems better to have a Pi article and a Tau article. Helloholabonjournihaonamastegutentag (talk) 20:00, 23 April 2015 (UTC)
Even in your latest message, you are completely ignoring both my pointer to past discussions on this issue and my response itself, which said nothing about what my own preference is. If you are really asking why I did what I did, this is a strange way to respond to the answer. If your question was rhetorical and your goal was to try to convert me into a tauist, you are misguided, in that I don't think my personal opinion on the issue is relevant for deciding how we cover the subject on Wikipedia. —David Eppstein (talk) 20:12, 23 April 2015 (UTC)
Sorry if it sounds like I am trying to convert you. I'm fine if you're a piist, but Wikipedia should be neutral. True, this isn't an ad, but I really think that we should have both Pi and Tau. Helloholabonjournihaonamastegutentag (talk) 15:05, 24 April 2015 (UTC)
My actual opinion on this issue is that you have to make a more or less arbitrary choice in defining the notation for this number, the choice we have already made may not be perfect but is good enough, and that the cost of switching to a new notation would vastly outweigh any benefit from greater convenience of that notation. But again, I don't think it should be relevant. Neutrality does not mean covering all the crackpot opinions in equal proportion to the widely-held mainstream position, which is what you seem to be arguing for here. —David Eppstein (talk) 16:07, 24 April 2015 (UTC)
For what it's worth, despite my personal preference for use of tau rather than pi (even at a switching cost), David is correct about how tau should be handled in WP. A separate article is not justified, and the topic is already adequately covered in related articles (Pi, Turn (geometry)). If the real-world notability of tau changes, we can update WP accordingly. —Quondum 17:04, 24 April 2015 (UTC)
By the way, I also think the benefits of switching have been somewhat overstated. I find myself writing π significantly more frequently than 2π (when talking about angles), mostly because in most situations where one could write 2π, writing 0 is simpler and better. —David Eppstein (talk) 18:03, 24 April 2015 (UTC)
I'm surprised. C = 0r? \hat{f}(\omega) = \int_{-\infty}^\infty f(t)\ e^{- 0 i t \omega}\,dt? You deal more with specific angles than with angular displacements or formulae? Face-devil-grin.svgQuondum 18:42, 24 April 2015 (UTC)
Integrals like that don't tend to come up in my research. And if they did, maybe I'd think of \sqrt\pi as more fundamental (e.g. in Stirling's formula and in the normalizing factor for Gaussians). But for example yesterday I was working on a paper that involved chains of circular arcs on a sphere, and I needed to avoid some special cases where the general results were invalid, so I wrote: "Given a closed spherical linkage C = \{c_1, ..., c_k\} where the c_i are the vertices, in order, embedded on a sphere in some configuration (i.e., with angles \alpha_i\notin\{0, \pi\} at each vertex c_i for i=1, \dots, k and with 0<\operatorname{arc}(c_i, c_{i+1})<\pi for each arc), ..." —David Eppstein (talk) 19:00, 24 April 2015 (UTC)
Sorry, I couldn't resist responding to 2π ≡ 0 (mod 2π) making 2π less important than π (maybe just my warped sense of humour about circularity). A debate would only be a discussion of aesthetics. —Quondum 21:11, 24 April 2015 (UTC)
This isn't meant to discuss the math behind why you like one or the other. I strongly believe that both Pi and Tau should have a page. Please provide your reasoning why you think that there should only be a Pi age and not a Tau one. Helloholabonjournihaonamastegutentag (talk) 05:33, 25 April 2015 (UTC)

Let's continue this topic at a more relevant location: Talk:Tau (mathematical constant) Helloholabonjournihaonamastegutentag (talk) 05:41, 25 April 2015 (UTC) Okay, I'll move it to Talk:Pi. Helloholabonjournihaonamastegutentag (talk) 22:57, 25 April 2015 (UTC)


Thank you. Issue resolved. Trout71 (talk) 23:54, 24 April 2015 (UTC)


The edit was to reflect that the school is a series of buildings and land, and it was the humans that occupy them that created the controversy, not the school itself. Point being that the school itself can not "do anything" without the help of people. --talk→ WPPilot  16:57, 26 April 2015 (UTC)

Ok, but there are more people at the school than its students. —David Eppstein (talk) 17:59, 26 April 2015 (UTC)
Agreed, that was a bit too narrow. talk→ WPPilot  20:28, 26 April 2015 (UTC)
My apologies to both of you for that accidental revert. ― Padenton|   23:22, 26 April 2015 (UTC)

Your second revert on Binary-coded decimal[edit]

Once you have been reverted you are not supposed to edit the contested material again. You are supposed to take it to the article talk page. Jeh (talk) 20:04, 29 April 2015 (UTC)

I am well aware of the 3-revert rule. There are topics in Wikipedia that are limited to only one revert, but this isn't one of them. —David Eppstein (talk) 20:19, 29 April 2015 (UTC)


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Hello, David Eppstein. You have new messages at Wikipedia:Articles for deletion/Ray Hefferlin.
Message added 01:40, 1 May 2015 (UTC). You can remove this notice at any time by removing the {{Talkback}} or {{Tb}} template.

Another user has requested your further input at the discussion. North America1000 01:40, 1 May 2015 (UTC)

Your monobook.css page[edit]

Hi; I notice that in User:David Eppstein/monobook.css you have the CSS rule

.ambox-Orphan{display: inherit !important;}

- please note that there is an error in this (almost certainly copied from an old version of Template:Orphan#Visibility) which causes incorrect display in some browsers.

To check this, visit this page and look at the second bullet (the one that precedes the text "This article is an orphan ..."). If this bullet is not in the same alignment as the other four, but displaced to the left, you can fix it by altering inherit to table in the CSS rule mentioned earlier. If that doesn't work either, alter it to block.

Template:Orphan#Visibility has been amended. --Redrose64 (talk) 19:44, 1 May 2015 (UTC)

Thanks, will do. I had noticed the misalignment but not considered it a serious enough problem to track down a fix for it. —David Eppstein (talk) 22:12, 1 May 2015 (UTC)

Reference errors on 3 May[edit]

Hello, I'm ReferenceBot. I have automatically detected that an edit performed by you may have introduced errors in referencing. It is as follows:

Please check this page and fix the errors highlighted. If you think this is a false positive, you can report it to my operator. Thanks, ReferenceBot (talk) 00:25, 4 May 2015 (UTC)

About Template:Mathematical art[edit]


Thanks for editing Template:Mathematical art on 19 April 2015. Recently, I have added ‎Mandelbrot set, Julia set and Penrose tiling as Notable figures in Template:Mathematical art. What is your opinion about this changes. D-4597-aR (talk) 19:47, 5 May 2015 (UTC)

They are not art. Artworks that feature those mathematical objects could be mentioned, but I fail to see the point of including any mathematical object that happens to have inspired art — the list would be far too long and indiscriminate. —David Eppstein (talk) 19:49, 5 May 2015 (UTC)

List of mathematical artists[edit]

Thanks again for editing Template:Mathematical art. Can we create an article entitled: List of mathematical artists? D-4597-aR (talk) 06:50, 6 May 2015 (UTC)

Vi Hart Article[edit]

I would like to know why you undid my edit to Vi Hart. According to Quite A Few Dictionaries, a mathematician is an expert in the field of mathematics, not a teacher or a person who makes youtube videos on it. Jcmcc (Talk) 07:01, 6 May 2015 (UTC)

You didn't read Talk:Vi Hart before making that edit, did you? Because we've been over all of this at great length already. In any case (1) being an expert and also making videos are not contradictory, (2) I would be very surprised if "not someone who makes videos" is actually part of the dictionaries you link to, (3) I think the correct definition is someone who practices mathematics, and making videos about it counts as such practice, (4) Hart has published research papers on mathematics, not just videos. —David Eppstein (talk) 07:08, 6 May 2015 (UTC)
Meh, I have no dog in this fight. Too much work over too small a thing. Ill stay out of the discussion. I just thought it was a painfully obvious change was all. Didn't even realize there would be a talk over it. If some people feel that publishing research papers makes one a mathematician, so be it. I guess I should add that to my resume considering that I wrote a published research paper on a geometrical theorem once when I was a freshman in highschool. Didn't realize the bar was set so low. Anyways, thanks for your time. Jcmcc (Talk) 09:28, 6 May 2015 (UTC)


Information icon There is currently a discussion at Wikipedia:Administrators' noticeboard/Incidents regarding an issue with which you may have been involved. The thread is Kheider_Adding_stuff_to_WP:Notability_.28astronomical_objects.29_to_point_to_at_AfD.The discussion is about the topic Wikipedia:Notability (astronomical objects). Thank you. ― Padenton|   00:54, 18 May 2015 (UTC)

Invitation to WikiProject TAFI[edit]

Today's Article For Improvement star.svg
Hello, David Eppstein. You're invited to join WikiProject Today's articles for improvement. Feel free to nominate an article for improvement at the project's Nominated articles page. Also feel free to contribute to !voting for new weekly selections at the project's talk page. If interested in joining, please add your name to the list of members. --Bananasoldier (talk) 00:59, 19 May 2015 (UTC)

A barnstar for you![edit]

Original Barnstar Hires.png The Original Barnstar
I've took a look at the historic of your contributions and recognized you as a very valuable contributor to this project. The amount of work you do for Wikipedia is really impressive and of very high quality. Anyway, here on Wikipedia there is always work to do, haha, it's really a never ending flow. :D I hope you to continue strong and forward! Sincerely, Lolaszvodikech (talk) 04:36, 22 May 2015 (UTC)
Thanks! —David Eppstein (talk) 04:37, 22 May 2015 (UTC)
I have a question for you :D... I'm a more or less experience user on the Portuguese Wikipedia under another account (since my English is not very good I created another to edit here), but I don't know if here the rules are different. Please look at this edit of mine. He is my friend and asked me if this was possible. I tried to do the same to his user talk page but got stopped by an an automated filter. Maybe I'm infringing some rule? Lolaszvodikech (talk) 05:06, 22 May 2015 (UTC)
Normally blanking someone else's talk page would not be considered appropriate but if he's your friend and you have his permission then I think there's no rule against it. —David Eppstein (talk) 05:09, 22 May 2015 (UTC)
I see. I will tell him to blank it himself then. :D Thanks. Btw, yes I have his permission!!! Lolaszvodikech (talk) 05:11, 22 May 2015 (UTC)
You might suggest that he add {{db-userreq}} to his user page. Then it can be deleted and not just blanked, so that its history is also not visible. However, this is not allowed for talk pages, so blanking is the best you can do for that. —David Eppstein (talk) 05:12, 22 May 2015 (UTC)
Right. Thanks again! I will explain it to him. Lolaszvodikech (talk) 05:16, 22 May 2015 (UTC)

Reuleaux triangle[edit]

Hi David,

I see you reverted my edit[1] because you seem to disagree that tangent is ambiguous. If you have a look at tangent, you can read that the tangent is the line that just touches the curve and that he word tangent comes from the Latin tangere, to touch. Finally it says that the tangent at a reference point may still not be uniquely defined because the curve is not differentiable at that point although it is differentiable elsewhere. In this case the left and right derivatives are defined..., which fits only in very few case with what is needed in the case of the realeaux triangle. The line of the box at Curve of constant width are not tangent in this usual mathematical sense, perhaps that is also why that page uses a more elaborate formulation: the perpendicular distance between two distinct parallel lines each having at least one point in common with the shape's boundary but none with the shape's interior, since most of the time not all of these parallel lines are tangent lines in the usual sense. I hope you will agree that there is a problem with using tangent as it means something more restricted than what is needed here. The full definition from Curve of constant width is good, but perhaps a bit long for using in its entirety... Do you have a suggestion for how to proceed? MarSch (talk) 08:18, 22 May 2015 (UTC)

Ok, the term we actually want is not tangent (because it is not defined at the three vertices) and not "line that touches" (because the meaning is unclear) but rather supporting line. —David Eppstein (talk) 15:29, 22 May 2015 (UTC)

Cellular automaton[edit]

Dear Dr. Eppstein,

I have a problem with a possible misunderstanding.

My contribution is not about "original research". The phrase "original research" (OR) is used on Wikipedia to refer to material—such as facts, allegations, and ideas—for which no reliable, published sources exist.

My contribution also cannot be considered as "spam and advertising": Latest revision as of 17:28, 22 May 2015 (edit) (undo) (thank) Joseph2302 (talk | contribs) (Reverted 2 edits by Lev Kalmykov (talk): Remove spam and advertising. (TW)).

My contribution is appropriate and accurate. It's not about my biography, my personality and it does not contain anything other than a title of the article published in the peer-reviewed journal with IF=1.231 which is indexing in 27 bibliographic bases and another title of the article published by 2013 in the peer-reviewed journal with IF=1.503 which is indexing in 7 bibliographic bases.

Re-posting was caused by the insufficiently correct deletion of this adequate contribution by David Eppstein.

In more details:

The first removal of my contribution “16:01, 21 May 2015‎ David Eppstein (talk | contribs)‎ . . (56,031 bytes) (-494)‎ . . (Undo WP:REFSPAM, WP:TOOSOON to tell whether this is of any significance)” looked biased because I provided a referenced link to the peer-reviewed article (Kalmykov LV, Kalmykov VL (2015) A Solution to the Biodiversity Paradox by Logical Deterministic Cellular Automata Acta Biotheoretica:1-19 doi:10.1007/s10441-015-9257-9) and it is already indexed in PubMed: Within a month, it is expected that the article will be indexed in all 27 bases. Besides, this contribution directly corresponds to the title of the published article and Wikipedia's section.

The second removal of the contribution “15:31, 22 May 2015‎ David Eppstein (talk | contribs)‎ . . (56,031 bytes) (-494)‎ . . (Undid revision 663513765 by Lev Kalmykov (talk) same reason. Primary source with absolutely no citations on Google scholar.)” also looked biased because Acta Biotheoretica has Impact Factor 1.231 and indexed in Science Citation Index, Science Citation Index Expanded (SciSearch), Journal Citation Reports/Science Edition, PubMed/Medline, SCOPUS, EMBASE, Google Scholar, EBSCO, CSA, CAB International, Academic OneFile, Biological Abstracts, BIOSIS, CAB Abstracts, CSA Environmental Sciences, Current Contents/ Agriculture, Biology & Environmental Sciences, Elsevier Biobase, EMBiology, Gale, Geobase, Global Health, INIS Atomindex, OCLC, SCImago, Summon by ProQuest, The Philosopher's Index, Zoological Record.

I also provided a link to another peer-reviewed article (Kalmykov LV, Kalmykov VL (2013) Verification and reformulation of the competitive exclusion principle Chaos, Solitons & Fractals 56:124-131 doi: It was published in 2013. Chaos, Solitons & Fractals has Impact Factor:1.503. This journal is indexed Science Citation Index; Scopus; Current Contents/Engineering, Computing & Technology; Mathematical Reviews; Research Alert; SCISEARCH; Zentralblatt MATH

This contribution also directly corresponds to the title of the article and Wikipedia's section.

Verification of the competitive exclusion principle and biodiversity paradox were the long-standing problems in theoretical ecology.

I am a novice at Wiki and I need more correct and understandable arguments. May I cite these articles using their titles and referenced links (as I did in these cases) for example after a month when our article from Acta Biotheoretica will be indexed in all 27 bibliographic bases?

Thank you for your time and consideration!


Lev Kalmykov (talk) 11:28, 24 May 2015 (UTC)

May 2015[edit]

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Elizabeth Losh[edit]

Did yo notice that the Elizabeth Losh AFD was created by an SPA named ucsh (Losh is at UCSD). This account appears to have done nothing else. Just created and put Losh up for AFD.E.M.Gregory (talk) 19:00, 29 May 2015 (UTC)

DYK for Marie-Louise Dubreil-Jacotin[edit]

Cas Liber (talk · contribs) 21:16, 30 May 2015 (UTC)


Hi professor, could you "de-draft" Draft:Mihran Apikyan please. Thanks. -- (talk) 10:00, 31 May 2015 (UTC)

Why me? Wouldn't it make more sense to ask someone who can read and evaluate the Turkish-language sources in that draft? —David Eppstein (talk) 01:15, 2 June 2015 (UTC)
Because you're a professor. -- (talk) 18:23, 24 June 2015 (UTC)

Wikipedia:Articles for deletion/Alicia Nash[edit]

I don't think WP:SNOW applies here; not every vote was "keep". Additionally, WP:BIOFAMILY says that one doesn't become notable solely for being related to someone famous. If you won't revert the closure, it would help to at least change the erroneous rationale given. Snuggums (talk / edits) 00:57, 2 June 2015 (UTC)

The rule about every !vote being keep is for withdrawing AfDs, a different situation. WP:SNOW is explicitly non-bureaucratic (i.e. it would be a mistake to try to apply a mechanical rule such as requiring every !vote to be a keep; see also WP:IAR) and is for situations where (1) there is a minuscule chance of a different outcome, and (2) prolonging the discussion could be harmful or otherwise wasteful of editors' time and energy. In this case, the discussion was starting to turn uncivil and the !votes were overwhelmingingly for keeping, so I believe WP:SNOW clearly applies. And no, I will neither revert the closure nor admit to the rationale being erroneous. You're welcome to take it to WP:DRV but arguments about erroneous closures are much more likely to be welcome there than arguments about inherited notability. —David Eppstein (talk) 01:11, 2 June 2015 (UTC)


Was this edit summary really necessary? Looks like a personal attack to me. Please don't do it again. -- WV 00:20, 7 June 2015 (UTC)

It was a critique of your writing, not of you as a person. It was also intended as a reductio ad absurdam argument for why that particular turn of phrase is I think unhelpful. If you're writing here, you should be willing to let others criticize and amend your writing. —David Eppstein (talk) 00:27, 7 June 2015 (UTC)
"Winkelvi is known as a Wikipedia editor who likes adding phrases known to be redundant" Do you have something factual to back this statement up? Because, if not, it's plainly and simply a personal attack. I'm fine with people criticizing my writing -- as long as it doesn't stray into attack territory. I'm fine with people amending my writing as long as it's factual, germane, and an improvement. ~
Substitute someone else's name if you prefer, or an entirely different subject, verb, object, and adjectival clause. The entire point of that sentence was to critique the overuse of "is known as" when it adds no additional information to a sentence. As for the content of the example sentence: there are two claims in it: that you like adding the phrase "is known as" and that this phrase is redundant. The first claim is the one that concerns you, is not particularly pejorative, and is documented by your recent edits. The second claim is again my point. —David Eppstein (talk) 00:49, 7 June 2015 (UTC)
First off, you obviously know nothing of my editing habits as I hardly ever have added "is known as" to any article. Fact is, that phrase (well, actually, it's "is known for") is in pretty much every biography article in Wikipedia. That's been the case long before I started editing three years ago. I'd be willing to wager that the phrase has been a part of Wikipedia biographies practically since Wikipedia started. Yes, my editing of the phrase in the manner it was being edited was erroneous. So what? That, in and of itself, puts me on the deserving end of an edit summary containing a personal attack (or sarcasm, or whatever you want to label it)? I admitted my error on the article's talk page. Whatever your reasons designed to excuse that particular edit summary, it's still not an example of "best practices" by editors. As I already stated, please don't do it again. -- WV 01:00, 7 June 2015 (UTC)
Ok. I will not use that edit summary again. —David Eppstein (talk) 01:02, 7 June 2015 (UTC)

I think the three uses of "known as" in that edit summary are very obviously intended to add no meaning (just as the "known as" in the article text added no meaning, and in that sense was redundant). That was the point of the edit summary as I read it: to emphasize that it adds no meaning to use "known as" in that way. It is not a personal attack in any germane sense. — Carl (CBM · talk) 00:53, 7 June 2015 (UTC)

List of mathematical artists[edit]


Recently I have created List of mathematical artists. But unfortunately it is being considered for deletion. Could you help to improve this article? D-4597-aR (talk) 15:02, 7 June 2015 (UTC)


Is not actually a policy that authorizes you to remove appropriate and well-sourced content. Actually it's the opposite. Please stop. Centrify (f / k / a Factchecker_has_annoying_username) (talk) (contribs) 23:37, 8 June 2015 (UTC)

It's not that I don't like it. (It being your recent edits to When contact changes minds). It's that it's an editorial opinion rather than actual fact, sourced to a newspaper whose editorials are well known to be heavily biased towards the conservative side of things, and more-than-usually-stupid even for them. So it fails WP:RS and WP:FRINGE. It's almost as stupid as the Republicans in California who think the drought there can be blamed on illegal immigrants, or the recent kerfuffle in Malaysia where the government there blamed an earthquake on tourists taking naked selfies. Frankly, your credulousness in believing that this material is worth including in Wikipedia does you no credit. —David Eppstein (talk) 23:42, 8 June 2015 (UTC)
Fails WP:Fringe? You're freaking delusional and I won't even bother reading the rest of your comment. Enjoy your day. Centrify (f / k / a Factchecker_has_annoying_username) (talk) (contribs) 23:45, 8 June 2015 (UTC)
The WSJ is fine for factual information. Its editorial section is a completely different kettle of fish. —David Eppstein (talk) 23:48, 8 June 2015 (UTC)
Its editorial section is just fine as a source for editorial opinions, tx. Centrify (f / k / a Factchecker_has_annoying_username) (talk) (contribs) 23:59, 8 June 2015 (UTC)


Greetings Mr Eppstein

Do you mean the hook as of itself or the material in the article supporting the hook? I have to personally give my opinion that the hook itself is too short and concise to possibly look like a copyvio, and I have made a change in the article material if that was the problem. If you have the time to give comments on the template about where exactly the changes should be made, I would be very grateful. '''tAD''' (talk) 13:58, 15 June 2015 (UTC)

I meant in the article. —David Eppstein (talk) 15:37, 15 June 2015 (UTC)

Sloan DYK[edit]

Symbol question.svg Hello! Your submission of Martha E. Sloan at the Did You Know nominations page has been reviewed, and some issues with it may need to be clarified. Please review the comment(s) underneath your nomination's entry and respond there as soon as possible. Thank you for contributing to Did You Know! Philafrenzy (talk) 11:07, 16 June 2015 (UTC)

James Wilson[edit]

Hi, I need you assistance. James Wilson attained the Universities of St. Andrews, Glasgow and Edinburgh, but never obtained a degree, see [2], [3] and [4]. However, this source[5] (published by the University of St. Andrews) claims that Wilson graduated from the University of St. Andrews in 1762. That's not true. What should be done when a supposedly reliable source publishes misleading information? Zenqueue (talk) 02:19, 17 June 2015 (UTC)

Say in the article that "X says he earned a degree from Y, but this is contradicted by the other sources P, Q, and R." That way we make the readers aware of the disagreement and let them make up their own mind about which is correct rather than trying to hide X's mistake. —David Eppstein (talk) 02:21, 17 June 2015 (UTC)
Thanks, but how do you say that in a page? I am confused. Can you give me an example? This source[6] claims that he never obtained a degree and this one [7] claims that he did. How can I point out in the page of James Wilson that the two sources contradict each other? Zenqueue (talk) 02:36, 17 June 2015 (UTC)
What's difficult about just saying exactly that? You can write it on my talk page, why not in the article? —David Eppstein (talk) 02:58, 17 June 2015 (UTC)
This is the first time I encountered a case where two sources contradict each other. I had no idea how people deal with such cases here. I have pointed out that fact in the page[8] and thank you very much for your assistance. Zenqueue (talk) 03:21, 17 June 2015 (UTC)


I am glad we seem to have gotten past our earlier missteps with each other. Glad to be working with you. Cheers. JbhTalk 22:04, 17 June 2015 (UTC)

Yes, I agree. —David Eppstein (talk) 22:05, 17 June 2015 (UTC)

Ever since we first met[edit]

I've had a powerful urge to run off and create that category at bottom and then not add you to it. I think I gets joke, can haz cookie? Centrify (f / k / a Factchecker_has_annoying_username) (talk) (contribs) 23:45, 17 June 2015 (UTC)

It's already been created once (by someone who, unlike you, didn't get the joke)...see Wikipedia:Categories for discussion/Log/2015 March 2. —David Eppstein (talk) 23:47, 17 June 2015 (UTC)
I had seen that but didn't drill down to the discussion. LOL @ kelapstick's comment. Thanks for that!
Eh, now that I think about it, I'd actually have to remove you from the cat in order to fully demonstrate joke-getting status. Sigh. Centrify (f / k / a Factchecker_has_annoying_username) (talk) (contribs) 00:09, 18 June 2015 (UTC)

draft: Audrey Stevens page[edit]

Thanks for your comments! I addressed some issues, but I did not see a way to change copyright info on the photos. The whole upload process was very confusing and I am not completely comfortable having those photos in the commons. Is there a way to use a photo without uploading to the Wiki Creative Commons? What exactly are you looking for when you want things to be "better sourced"? I think the personal details are important to those interested in the history of women in science. Other women scientists of similar age, such as Sylvia Earle and Jane Goodall, did not stick to one spouse the way Audrey did, and did not put their children at such high priority. I am very unclear how this normally works, but I moved your comment to a talk page for the Audrey page, and also wrotehere on your talk page. Let me know which is better? Any feedback/advice much appreciated! Thanks again!Soilmicro (talk) 01:14, 20 June 2015 (UTC)Soilmicro

Re better sourcing: see WP:RS for what is acceptable as a source. If we can't source some piece of information, better just not to include it. —David Eppstein (talk) 04:18, 21 June 2015 (UTC)

Re: Pamela Zave[edit]

Thank you for creating this article. I added it to Wikipedia:Wiki Loves Pride 2015/Results, which tracks LGBT-related content created during the month of June as part of the annual Wiki Loves Pride campaign. If you happen to create other LGBT-related articles this month, feel free to update the Results page accordingly. Thanks again! ---Another Believer (Talk) 16:06, 20 June 2015 (UTC)

5th Annual Wiknic[edit]

5th Annual Wiknic (Saturday, July 11, 2015, ~9:30am-4pm)
BBQ - 001.jpg

Dear fellow Wikipedian,

You are cordinally invited to the fifth annual Los Angeles Wiknic!

The Wiknic is a part of the nationwide Great American Wiknic. We'll be grilling, getting to know each other better, and building the L.A. Wikipedia community! The event is tentatively planned for Pan-Pacific Park (map) and will be held on Saturday, July 11, 2014 from 9:30am to 4pm or so. Please RSVP and volunteer to bring food or drinks if possible!

I hope to see you there! Howcheng (talk) - via MediaWiki message delivery (talk) 19:40, 21 June 2015 (UTC) Join our Facebook group here! To opt out of future mailings about LA meetups, please remove your name from this list.

Graph family/Individual Graph[edit]

Helloooo !

I'm here to talk about your revert on the "Chang Graphs" page. First, let me mention that I am a total beginner here.

I am a contributor to the software Sage ( and I got very interested by semantic databases recently. I have been using wikipedia through dbpedia (, which I try to "link" with Sage. At the moment, it involves listing all graphs that Sage can build and matching them (in a future 'open' database) with Wikipedia entries.*+where+%7B%3Fp+dcterms%3Asubject+category%3AIndividual_graphs%7D+LIMIT+1000&format=text%2Fhtml&CXML_redir_for_subjs=121&CXML_redir_for_hrefs=&timeout=30000&debug=on

Now, several attributes are defined in dbpedia for "individual graphs" (number of vertices, number of edges, chromatic numbers), but of course this has absolutely no meaning whatsoever if what Wikipedia registers as an 'individual graph' (for which those parameters are defined) is a family of graphs (whose elements may have different number of vertices/edges/chromatic number). You just cannot manage a family of graphs as you would manage an individual graph, and this is the difference (which shows in a semantic database) that I am trying to fix here. I have the same problem with these other entries:

Both mathematically and semantically, it makes more sense to consier them as a family of graphs. It is particularly obvious in the latter case that a classification as a "Graph Family" would be more appropriate.

It seems that we also have many graphs in Sage that are not known to wikipedia, and which I will add soon. Some, funnily, are known to the french wikipedia. Is it proper to translate those pages to english in such a situation?


Nathann — Preceding unsigned comment added by Nathann.cohen (talkcontribs) 09:47, 23 June 2015 (UTC)

I think of that article as being about three individual graphs. A graph family is generally an infinite thing (otherwise most of the problems one cares about like recognition etc become trivial). As for whether to translate missing French articles to the English Wikipedia (or add articles from Sage to Wikipedia): yes, this is usually a good idea. Just be sure to include reliable sources such as published journal articles that include all the claims about these graphs that you include in the article. —David Eppstein (talk) 16:25, 23 June 2015 (UTC)

Would you have anything against filing them under "Graph Families"? I can hear that you do not mind having finite collections of graphs under "Individual Graphs", but if you do not mind to bend the definition this way, why wouldn't we move them to "Graph Families"? There is nothing in mathematics that supposes that a family is infinite, and clearly this is where the "Petersen Family" should be filed. That would also be more correct semantically in dbpedia.


Nathann — Preceding unsigned comment added by Nathann.cohen (talkcontribs) 17:32, 23 June 2015 (UTC)

Nomination of Jon Lee (mathematician) for deletion[edit]

A discussion is taking place as to whether the article Jon Lee (mathematician) is suitable for inclusion in Wikipedia according to Wikipedia's policies and guidelines or whether it should be deleted.

The article will be discussed at Wikipedia:Articles for deletion/Jon Lee (mathematician) until a consensus is reached, and anyone is welcome to contribute to the discussion. The nomination will explain the policies and guidelines which are of concern. The discussion focuses on high-quality evidence and our policies and guidelines.

Users may edit the article during the discussion, including to improve the article to address concerns raised in the discussion. However, do not remove the article-for-deletion notice from the top of the article. Labalius (talk) 02:21, 25 June 2015 (UTC)

DYK nomination of Lixia Zhang[edit]

Symbol question.svg Hello! Your submission of Lixia Zhang at the Did You Know nominations page has been reviewed, and some issues with it may need to be clarified. Please review the comment(s) underneath your nomination's entry and respond there as soon as possible. Thank you for contributing to Did You Know! Yoninah (talk) 09:27, 25 June 2015 (UTC)

DYK for Reuleaux triangle[edit]

 — Chris Woodrich (talk) 02:50, 26 June 2015 (UTC)


Cornflower blue Yogo sapphire.jpg

scientific color to the Main page
Thank you, computer scientist, for adding pictured insight to the Main page with quality articles such as Reuleaux triangle, Temple of Kwan Tai, Navarro River Redwoods State Park, Anant Sadashiv Altekar, teaching about of a broad range of topics including women in science such as Marie-Louise Dubreil-Jacotin, for serving as an admin and uploading images and diagrams, for earning the Mensch's Barnstar, - you are an awesome Wikipedian!

--Gerda Arendt (talk) 06:25, 26 June 2015 (UTC)

Thank you! —David Eppstein (talk) 08:48, 26 June 2015 (UTC)
I edit the English Wikipedia very rarely (English is not exactly the language I'm most comfortable with), and even so I was able to notice his work in many articles. I totally agree with this Wikipedian Prize (barnstar) you gave to him. Totally deserved. If I was someone I would nominate David Eppstein to be awarded some honor outside of Wikipedia, like the "Clay Award for Dissemination of Mathematical Knowledge" or something similar, but I'm just an undergraduate student in South America... Simba Oliver Cat (talk) 18:38, 26 June 2015 (UTC)


The deletion of my contribution is O.K. Would an external link to be Hendecagon, an approximate construction informative?
Greetings Petrus3743 (talk) 12:10, 30 June 2015 (UTC)

Please see WP:ELNO — I suspect that as a self-published piece on an open wiki, that is still not a good link according to the criteria there. —David Eppstein (talk) 15:34, 30 June 2015 (UTC)