Talk:Life-like cellular automaton

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This pattern if entered in Non-deterministic births(only),will result in chaotic glider world.

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Neighbourhood Notation

I added the info on the initial letter in the rule notation since this is the artical on "Life-like CA" and Life-like (chaotic with gliders) universes certainly occur in neighbourhoods other than Moore (Hex and Von Neumann). I'll add it back once, if it's still felt that it's nonrelevant we can go from there. —Preceding unsigned comment added by Alpha Omicron (talk • contribs)

I asked for a source. Where is your source? What software uses this augmented notation? I have been very tempted for a while to switch the article over to B3/S23 style as used in RLE by Golly, LifeLab, etc. [1] [2] [3]. I think it's better documented as part of a format multiple programs understand, and easier to read for humans too since the B and S serve as reminders for which numbers mean what. But perhaps this article could use a section describing different rule formats (e.g. also Wolfram's binary coded decimal). —David Eppstein 15:32, 28 March 2007 (UTC)

This notation is used by Life32, easily the fastest software for Life-like CAs. In Life32 the S and B are optional, though I usually find them superfluous. Maybe a vote should be held on what sort of notation to use, then have that notation implemented unilaterally across all CA-related articles. Alpha Omicron 14:28, 29 March 2007 (UTC)

That's still not a source. Is there an online manual that could be used as a source for this notation? —David Eppstein 15:31, 29 March 2007 (UTC)

You asked for a software source. That's it. After MCell Life32 is probably the most popular CA software. I think MCell supports that notation as well. I don't think Johann Bontes made up the notation for Life32, so some earlier documentation must be floating around somewhere. I'm fine with leaving that notation out until another source turns up though. Alpha Omicron 03:11, 31 March 2007 (UTC)

I agree with David, B3/S23 is far more legible than 23/3! Cyb3r 22:14, 11 November 2007 (UTC)

Slightly less life-like CA

This morning I added a bunch of bibliographic references to academic papers by Bays, Evans and Pivato. They were removed by David Eppstein about ten minutes later, on the grounds that they are not technically about “life-like″ CA in the sense defined here (i.e. they do not use the Moore neighbourhood). Eppstein suggests these CA should go into another article. Perhaps someday they will, although it seems to me sort of silly to have an article on “Life-like CA″ and then another article on “Slightly less life-like CA″. This article seems like the right place to mention Evan's Larger than Life or Bay's three-dimensional Life variants. If these CA do not fit into the article's current (Moore neighbourhood) definition of “life-like″ CA, then perhaps this means that the current definition is too specific. For these reasons, I have “reverted” Eppstein's changes and reinserted this material into the article. I hope that this is acceptable.

It seems unfortunate to me that this article does not cite a single academic paper on ”life-like″ CA, despite the fact that there are clearly many interesting examples which have been studied by a number of people. Could someone provide some more literature references, please? —Preceding unsigned comment added by 70.24.10.41 (talk) 19:33, 8 December 2008 (UTC)

The Wolfram paper, already cited, is an academic paper with plenty of material on this general class of CAs; Packard & Wolfram JSP '85 is more specifically about it and some related classes. I don't have online subscription access, but I suspect from the title and abstract that Boccara & Roger, IJMPC '99 is also on this class. Adamatsky and Komosinski have published a paper about MCell that describes this class. my paper on spaceship-finding algorithms also concerns this general class. Adachi et al, "Occurrence of gliders in an infinite family of life-like cellular automata" uses outer totalistic rules and Moore neighborhoods but with larger radii. Feel free to add these or other relevant references to the article. —David Eppstein (talk) 21:18, 8 December 2008 (UTC)

The Chaotic Universe

I miss a description of 23/37. This configuration might not be that interesting to structuralists, but for me - as a meteorologist - it is fascinating. "Chaotic growth" can be initiated with very simple patterns - try this one for example:

  xxx
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or this one:

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There are all sorts of interesting questions pertaining to this configuration:

  1. Is this growth boundless ?
  2. What is its asymptotic density (live cells / total ones) ?
  3. What is the minimum pattern to generate "chaotic growth" ?
  4. What is the "speed" of this growth (it is clearly sublinear) ?
  5. Do different patterns that initiate chaotic growth generate significantly different ones:
     a. In asymptotic density.
     b. In growth speed.
     ?
  6. Or is this an intrinsic property of the 23/37 configuration ?

—Preceding unsigned comment added by 82.93.67.168 (talk) 19:32, 29 May 2008 (UTC)

There are huge numbers of rules that exhibit chaotic growth not unlike this; B37/S23 isn't unusual in this respect. Since there's no way we can individually describe all the 262144 different life-like rules, and since we need to avoid original research here, we must limit ourselves to those that have reliable sources available elsewhere. If you can find such sources, please say so, but I don't know of any. (By the way, I do have a web site on this rule. But since this site also has a page for each of the 262143 other life-like rules, the existence of this page is not useful for deciding which rules to include here.) —David Eppstein (talk) 20:43, 29 May 2008 (UTC)

262144

Perhaps the article itself should point out that there are 262144 possible Life-like automata that meet this definition. I don't think this counts as original research - it is just 2^18. —Preceding unsigned comment added by 62.232.250.50 (talk) 12:58, 11 May 2011 (UTC)

In any case it's probably not hard to source. I've gone ahead and made this change. I've also been thinking I should expand the list to include the rules mentioned in my own recent survey "Growth and Decay in Life-Like Cellular Automata" (see arXiv:0911.2890 for the free version or doi:10.1007/978-1-84996-217-9_6 for the published version) but I'm a bit hesitant because of the conflict of interest. If anyone else has an opinion on whether this would be a good or bad idea I'd be interested to see it. —David Eppstein (talk) 14:52, 11 May 2011 (UTC)

Carter Bays / 'generalization'

"Carter Bays has proposed a variety of generalizations of the Game of Life to three-dimensional CA defined on Z3"

I'm being pedantic but I'm not sure show switching from 2D to 3D would constitute a 'generalization'. (Certainly it might constitute a widening of the field, further research, etc.)

Perhaps if Bay's has done work on n-dimensional (or arbitrary dimensional) versions that would count as generalizing. (Or in arbitrary topologies, as the part about triangular grids suggests.) I think this needs rewording to either a) not state the 3D life is somehow more general the 2D life, or b) explain what it was the Bays did thay really constitutes a generalization. 86.168.41.180 (talk) 15:26, 1 December 2014 (UTC)

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Simulator

I remember seeing various simulators where you enter the rule string, and it simulates it. Is there an online such tool? If so, I think we should add it to the external links.