User talk:David Eppstein/2012a

DYK for Hendy Woods State Park
Casliber (talk · contribs) 05:48, 1 January 2012 (UTC)

The Dynamic Programming recursive scheme
The books on Dynamic Programming that I know claim that Bellman used it first. The application for computing minimal distance in a graph is named after Bellman and Ford. — Preceding unsigned comment added by Shuroo (talk • contribs) 10:31, 1 January 2012 (UTC)

Claudia Black etc.
I've posted a request at ANI to have those talk pages semi'd for awhile. You may do the honors yourself if you wish. The backstory on that IP-hopper is that he fancies this particular woman to be his girlfriend. He's using the real-life name of someone on Facebook. Or something like that. Anyway, it's all a BLP-violation, which I would think would override the usual concerns about blocking access to talk pages. ←Baseball Bugs What's up, Doc? carrots→ 07:15, 3 January 2012 (UTC)
 * I blocked the IP but I imagine he or she will just come back quickly enough on a different one. —David Eppstein (talk) 07:15, 3 January 2012 (UTC)
 * Yes. That's why the talk pages need to be semi'd. Name-dropping is another affected item. The Rango (2011 film) talk page is already semi'd short-term. That article's age is where this kind of started, in late November. You can see the rev-del's on some of the entries. ←Baseball Bugs What's up, Doc? carrots→ 07:16, 3 January 2012 (UTC)


 * FYI I created an edit filter request at WP:EF/R. Since you guys are more familiar you might want to chime in, in case I missed anything. causa sui (talk) 22:55, 3 January 2012 (UTC)

DYK for Temple of Kwan Tai
Casliber (talk · contribs) 16:02, 5 January 2012 (UTC)

DYK for Healdsburg Memorial Bridge
The DYK project (nominate) 00:02, 6 January 2012 (UTC)

Added pic
I added File:Healdsburg Bridge 193708pu.jpg from HABS/HAER to your wonderful article. I then noticed that you'd removed an earlier color pic - looks to be the same bridge to me - but one never knows, do one?  Smallbones (talk) 01:52, 6 January 2012 (UTC)
 * Thanks for the image, and thanks also for the complement. Your image is clearly the right bridge, but I was unsure about the one I found. —David Eppstein (talk) 02:07, 6 January 2012 (UTC)

Disambiguation link notification
Hi. When you recently edited Dessin d'enfant, you added a link pointing to the disambiguation page Hyperbolic plane (check to confirm | fix with Dab solver). Such links are almost always unintended, since a disambiguation page is merely a list of "Did you mean..." article titles. Read the FAQ* Join us at the DPL WikiProject.

It's OK to remove this message. Also, to stop receiving these messages, follow these opt-out instructions. Thanks, DPL bot (talk) 11:29, 6 January 2012 (UTC)

Articles for deletion/Qi (programming language) (2nd nomination)
Would you be interested in voicing your opinion at Articles for deletion/Qi (programming language) (2nd nomination)? Cheers, —Ruud 19:59, 6 January 2012 (UTC)

Messaggione
Ci vediamo il 21 aprile. ciao coyote. --86.24.46.135 (talk) 00:06, 21 January 2012 (UTC)

First textbook on graph theory
As you no doubt realize, the "citation needed" tag's role is to highlight an unsupported statement that could use a reference. Since you added a reference, the tag achieved its objective. So why did you feel compelled to lecture me in your edit summary? I'm not obligated to fill every reference gap I see in wikipedia. In my opinion, drawing someone's attention to a gap is still performing a service, but it seems like you're accusing me of laziness or incompetence. &mdash; Myasuda (talk) 16:21, 28 January 2012 (UTC)

beans and categories
Hello David,

I just saw your note at Brad7777's talk page. Perhaps I do not appreciate the seriousness of the issue, but for me:
 * a) what others call consensus (about category structure) was never discussed, so changing one arbitrary structure with another one can not cause too much damage;
 * b) I do not get the opinion that Brad7777 is unreasonable (or does not respond to remarks). I think that out of the crooked timber of mathematics no perfect category structure is possible, therefore it is sometimes necessary to have logical flaws in it to keep it convenient. Apparently, he disagrees, but well -- this is a legitimate disagreement.
 * c) In my somewhat idealistic opinion, we mathematicians should be able to communicate with each other without appealing to ANI, RFC, and other frightening abbreviations. Therefore this, this, and some of the remarks here make me quite unhappy.

Best regards, Sasha (talk) 17:40, 5 February 2012 (UTC)

Justin Friesen‎
Hi David. You removed the PROD from Justin Friesen‎ on the basis that there had been a previous AfD. The consensus of that discussion was to delete the article, which was done. The article I PRODded was a new article, not the one which was discussed at AfD. I will bring the article back to AfD, but I do not believe that your rationale for removing the PROD was correct. Pburka (talk) 22:47, 5 February 2012 (UTC)
 * It was a rewritten version of the article (enough to protect it from G4 speedy deletion) but it was on the same subject as the previous AfD at the same title. That's enough to prevent it from being prodded again. —David Eppstein (talk) 23:31, 5 February 2012 (UTC)
 * Fair enough. I had interpreted that section to mean that articles which had survived an AfD couldn't be PRODded. Your more conservative interpretation is probably the safer one. Pburka (talk) 00:04, 6 February 2012 (UTC)

MSU Interview
Dear David,

My name is Jonathan Obar user:Jaobar, I'm a professor in the College of Communication Arts and Sciences at Michigan State University and a Teaching Fellow with the Wikimedia Foundation's Education Program. This semester I've been running a little experiment at MSU, a class where we teach students about becoming Wikipedia administrators. Not a lot is known about your community, and our students (who are fascinated by wiki-culture by the way!) want to learn how you do what you do, and why you do it. A while back I proposed this idea (the class) to the community HERE, were it was met mainly with positive feedback. Anyhow, I'd like my students to speak with a few administrators to get a sense of admin experiences, training, motivations, likes, dislikes, etc. We were wondering if you'd be interested in speaking with one of our students.

So a few things about the interviews:
 * Interviews will last between 15 and 30 minutes.
 * Interviews can be conducted over skype (preferred), IRC or email. (You choose the form of communication based upon your comfort level, time, etc.)
 * All interviews will be completely anonymous, meaning that you (real name and/or pseudonym) will never be identified in any of our materials, unless you give the interviewer permission to do so.
 * All interviews will be completely voluntary. You are under no obligation to say yes to an interview, and can say no and stop or leave the interview at any time.
 * The entire interview process is being overseen by MSU's institutional review board (ethics review). This means that all questions have been approved by the university and all students have been trained how to conduct interviews ethically and properly.

Bottom line is that we really need your help, and would really appreciate the opportunity to speak with you. If interested, please send me an email at obar@msu.edu (to maintain anonymity) and I will add your name to my offline contact list. If you feel comfortable doing so, you can post your name HERE instead.

If you have questions or concerns at any time, feel free to email me at obar@msu.edu. I will be more than happy to speak with you.

Thanks in advance for your help. We have a lot to learn from you.

Sincerely,

Jonathan Obar --Jaobar (talk) 02:51, 9 February 2012 (UTC)

notability question
You usually take a slightly narrower view of science notability than I do, so perhaps you might want to check my reasoning in Articles for deletion/Amer Iqbal.  DGG ( talk ) 20:55, 10 February 2012 (UTC)

Diameter symbol
Hi. I'm sorry, i might be dense, but i don't see how your reference supports the whole statement in that article. The only thing i found in the PDF says that the symbol is not "the character ⌀" and is not "letter "o" with stroke". -- Jokes Free4Me (talk) 23:45, 11 February 2012 (UTC)
 * PS Could http://www.unicode.org/charts/PDF/U2300.pdf be used as a source? (Although i'm not 100% clear on what the arrow means; but contrasting it with the equal and equivalent signs in similar context it's somewhat obvious, and good enough for me.)
 * Do you really need a source for a statement as obvious as that? They're all different unicodes and hence are distinct. It's like asking for a source for the statement that 1 ≠ 2. The source does clearly support the statement that the diameter symbol is distinct from other things that look sort of like it, even though it doesn't mention precisely the same set of other things that sort of look like it as our article does. —David Eppstein (talk) 23:47, 11 February 2012 (UTC)
 * My problem is mainly due to the fact that the symbol existed before Unicode. They decided to allocate it to a different code, fine, but that doesn't mean that the symbol in use before was different than any of those other things. And i don't care if the Unicode characters now differ, i'm interested in the symbol that i would manually draw on paper. I guess i should just check the ISO/ANSI definitions? -- Jokes Free4Me (talk) 22:54, 12 February 2012 (UTC)
 * Here's a nice pre-unicode example clearly describing the diameter symbol as a distinct shape formed from a circle and a slash at a specified angle (and not formed as a letter of the Greek alphabet etc). —David Eppstein (talk) 23:53, 12 February 2012 (UTC)

Disambiguation link notification
Hi. When you recently edited Supporting line, you added a link pointing to the disambiguation page Annulus (check to confirm | fix with Dab solver). Such links are almost always unintended, since a disambiguation page is merely a list of "Did you mean..." article titles. Read the FAQ* Join us at the DPL WikiProject.

It's OK to remove this message. Also, to stop receiving these messages, follow these opt-out instructions. Thanks, DPL bot (talk) 10:48, 16 February 2012 (UTC)

Euler's totient function – small font and (supposedly) two columns
Hi, David.

I see that in the Notes section of the Euler's totient function article, you went back to the smaller font. Why was the Notes section in that style in the first place? I don't see the point of having a small font. In fact, I found it more difficult to read. The comment from the editor that made it that way read, "+ref (2 columns) template for Notes section". I never saw two columns – just smaller font. Could you please explain to me what is gained by having the Notes section in that style? — Anita5192 (talk) 05:48, 18 February 2012 (UTC)


 * Sorry, David. I looked at your comment but not at the article.  I thought that you put it back exactly the way it was.  Actually, I like the font the way it is now.  But I still do not understand what you did and why.  Could you please explain this so I will understand this in the future? – Anita5192 (talk) 06:00, 18 February 2012 (UTC)


 * reflist can be used for formatting footnotes, and refbegin/refend for formatting non-footnote references. Both reflist and refbegin can take an additional parameter, either a number of columns or something like I used, 30em to set a fixed column width and use as many columns as will fit in that width (a better choice than a fixed number of columns, so that the page will look ok devices with different screen sizes). —David Eppstein (talk) 07:33, 18 February 2012 (UTC)


 * Thank you for the information, David. I was not aware that some textual features are currently supported only by newer versions of some browsers.  — Anita5192 (talk) 19:48, 18 February 2012 (UTC)

Erdős number redlink cleanup
Thanks so much for what you're in the process of doing with List of people by Erdős number. It should have been done a long time ago, and you're just the knowledgeable sort of person to do it. Good job. Ntsimp (talk) 04:39, 19 February 2012 (UTC)
 * You're welcome, and thanks for the appreciation. —David Eppstein (talk) 21:01, 19 February 2012 (UTC)

Disambiguation link notification
Hi. In your recent article edits, you've added some links pointing to disambiguation pages. Such links are almost always unintended, since a disambiguation page is merely a list of "Did you mean..." article titles. Read the FAQ* Join us at the DPL WikiProject.


 * Lila Kari (check to confirm | fix with Dab solver)
 * added links pointing to Undecidability and Nondeterminism


 * Rod Downey (check to confirm | fix with Dab solver)
 * added a link pointing to Complexity theory

It's OK to remove this message. Also, to stop receiving these messages, follow these opt-out instructions. Thanks, DPL bot (talk) 10:30, 23 February 2012 (UTC)

3SUM Edits
Hey David, I noticed that you've been keeping an eye on the 3SUM page. I've added two algorithms as examples and changed some (incorrect?) wording that says there's only a single n2 algorithm. I'd appreciate it if you could double-check my work if you have time. Thanks! fintler (talk) 20:49, 23 February 2012 (UTC)

Your anti-Western and anti-Ukrainian edits, promoting subversive pro-Putin and pro-Russian views
Hey, David. You should stop pushing your anti-Western and anti-Ukrainian agendas through Wikipedia. Your pro-Putin and pro-Russian bias is obvious, but Wikipedia is NOT a place to promote your subversive ideas. Please familiarize yourself with Wikipedia policies and please consider contributing to Wikipedia constructively. — Preceding unsigned comment added by 76.102.173.102 (talk) 19:37, 25 February 2012 (UTC)
 * Pro-Putin? Srsly? Heh, thanks for the laugh of the day. —David Eppstein (talk) 19:58, 25 February 2012 (UTC)
 * David: Wikipedia articles are not a laughing matter. Wikipedia should not be used by the likes of you to promote anti-Western and anti-Ukrainian ideas. — Preceding unsigned comment added by 76.102.173.102 (talk) 21:26, 25 February 2012 (UTC)
 * Since when is calling a Pole a Pole an anti-Western thing to do? Poland is to the west of Ukraine, no? —David Eppstein (talk) 21:29, 25 February 2012 (UTC)
 * Banach is obviously not a Pole. He was born in the area populated by Rusyns and Ukrainians, he worked most of his career in Lviv Ivan Franko National Ukrainian University, he was a member of Ukrainian academy of science. Promotion of questionable ideas pushed forward by a small clique of chauvinistic Poles definitely offends pro-Western Ukrainians. You are helping an old Putin anti-Western plan of alienating Ukrainians and splitting the Western society. Thus, David Epstein, your actions are anti-Western, anti-Ukrainian, anti-Wikipedia and pro-Putin.


 * Hey, at least you're not being accused of being a "Polish nationalist". Volunteer Marek 21:45, 25 February 2012 (UTC)
 * Once it was Schauder, now it's Banach's turn :) Sasha (talk) 22:29, 25 February 2012 (UTC)


 * The IP has been blocked, per the ArbCom ruling on Eastern European articles (from where our editors flee to edit peacefully in the relatively calm of Palestine-Israel and Northern Ireland) and a specific editor's blocking.
 * Be well! 11:05, 26 February 2012 (UTC) — Preceding unsigned comment added by Kiefer.Wolfowitz (talk • contribs)

New articles: Robert G. Bland and Jon Lee (mathematician)

 * Oh well, so much for the entertainment. Thanks for dealing with this appropriately. By the way and unrelatedly, with your interests in mathematical optimization, you might want to take a look at two new articles I just added: Robert G. Bland and Jon Lee (mathematician). —David Eppstein (talk) 17:24, 26 February 2012 (UTC)
 * Both look good.
 * Jon Lee's brother is also a mathematician with similar interests. I think that Jon or his brother wrote a nice description of an early nasty example for Dantzig's simplex algorithm in SIAM Review.
 * One wonders whether Jack Edmonds named Bland Oriented Matroids to honor Bland or just because he could not resist the imp of the perverse whispering in his ear.
 * Cheers, Kiefer .Wolfowitz 17:14, 6 March 2012 (UTC)

Birman
Hi David, I didn't get a very clear sense of your position on the comments on Yau. It seems to me there is an obvious problem with BLP. Again, my quotes were not "scare quotes"; rather, I was literally quoting a comment made another editor. Tkuvho (talk) 21:13, 25 February 2012 (UTC)
 * BLP says we should avoid unsupported or unreliably published negative statements about living people. This material is neither unsupported nor unreliable. —David Eppstein (talk) 21:31, 25 February 2012 (UTC)
 * Which material are you referring to? Again, her claim that the refereeing process was "thrown out of the window" is unsupported and unreliable, as well as apparently incorrect.  Tkuvho (talk) 21:35, 25 February 2012 (UTC)
 * You are stating your personal opinion about the correctness and reliability of this claim, but that's not the same as the technical meaning of being a reliable source for the purposes of Wikipedia. It is important not to edit here based on opinions. —David Eppstein (talk) 21:37, 25 February 2012 (UTC)
 * Certainly it should be easy to source the fact that the paper was carefully refereed. She does not provide any evidence to the contrary.  Her claim is therefore dubious and apparently incorrect.  Besides, nobody is arguing that Cao's paper is not correct.  What exactly does the refereeing process have to do with this?  This appears to be a case of emotional reaction leading to incoherence.  Tkuvho (talk) 21:42, 25 February 2012 (UTC)
 * Note that WP:BLP speaks of "high degree of sensitivity" and "must be written conservatively and with regard for the subject's privacy". I fail to see how the comment meets such standards.  Tkuvho (talk) 21:46, 25 February 2012 (UTC)

WP:EAR
You have been referred to in a thread at Editor assistance/Requests.  Spinning Spark  09:15, 26 February 2012 (UTC)

Severe Tire Damage
I am going to revert your change to the Severe Tire Damage page in which you added Anna Karlin as a band member. There are multiple problems with this. First, when she was in the band, it was not called "Severe Tire Damage". Second, you cited a web page in which she is only listed as a "friend of the band" and you did not list the other friends. The proper solution (which I will undertake) is to expand the band members section more sensibly. strubin (talk) 18:42, 26 February 2012 (UTC)
 * If you look more carefully at what it says in her "friend of the band" entry, it says former member. Also, the page describing the main reason for the band's notability says "Anna Karlin is with the band then" in its first lines. —David Eppstein (talk) 19:06, 26 February 2012 (UTC)
 * The page you are citing is old (you had to find it on a wayback machine) and not citation-worthy on Wikipedia. I have fixed the STD page in a more complete way (adding Joel Jewitt, for example).  Some details may be missing and can be filled-in later. strubin (talk)  —Preceding undated comment added 21:50, 26 February 2012 (UTC).

Disambiguation link notification
Hi. In your recent article edits, you've added some links pointing to disambiguation pages. Such links are almost always unintended, since a disambiguation page is merely a list of "Did you mean..." article titles. Read the FAQ* Join us at the DPL WikiProject.


 * Anna Karlin (check to confirm | fix with Dab solver)
 * added a link pointing to Competitive analysis


 * Darrell Long (check to confirm | fix with Dab solver)
 * added a link pointing to Bandwidth


 * Gadget (computer science) (check to confirm | fix with Dab solver)
 * added a link pointing to Subgraph

It's OK to remove this message. Also, to stop receiving these messages, follow these opt-out instructions. Thanks, DPL bot (talk) 10:41, 1 March 2012 (UTC)

Celtic graphs: FYI
Hi David!

The King Crimson album Discipline has had two graphs, inspired by Celtic traditions.

I imagine that e.g. The Mathematical Intelligencer would publish a study of them, or that they might be good examples for conference presentations.

Best regards, Kiefer .Wolfowitz 12:12, 2 March 2012 (UTC)
 * One knotwork image (for Discipline Global Mobile) led today's DYK, the first time in 20 or so DYKs that an image appeared. Another knotwork image was donated for Guitar Craft, also by Steve Ball. In his day job, he led the development of the sound system for Windows Vista, according to NPR; Vista's start up sound was created with Ball's friend Robert Fripp (of King Crimson). Kiefer .Wolfowitz 17:36, 25 March 2012 (UTC)

1248 Jugurtha
You've added a major error to the article. I don't think that any astronomer or physicist worth their salt would have had this issue so t seems to me that you're not qualified or (apparently) able to read the primary sources on this subject.

And as a penalty for bending the rules here, I'm not going to tell you what the problem is, you'll have to work it out for yourself. Of course you could just leave it, but then what would be point of having the article? There are reasons for the policies of Wikipedia, and this is as good an example as any I've seen.- Sheer Incompetence (talk) Now with added dubiosity! 03:43, 3 March 2012 (UTC)
 * WP:SOFIXIT. What do you hope to accomplish by taunting me about it instead? If you mean the confusion between synodic and siderial periods, yes, it seems to be an error, but the source gives only the synodic period and the infobox seems to have room only for the siderial period. —David Eppstein (talk) 04:23, 3 March 2012 (UTC)
 * That would be because you introduced a major error into the article that made me go 'WTF' and forced me to pull the primary sources and check, and secondly because this article's subject isn't really wp:notable either. Anyway, while that error is vaguely amusing, that ain't it.- Sheer Incompetence (talk) Now with added dubiosity! 05:16, 3 March 2012 (UTC)
 * Well, if you don't fix it yourself, it's likely to stay broken, whatever it is. I have better things to do than play stupid guessing games with you. —David Eppstein (talk) 05:28, 3 March 2012 (UTC)
 * In future I recommend you stay away from this type of article then. You clearly don't have any physical intuition about any of it.- Sheer Incompetence (talk) Now with added dubiosity! 05:51, 3 March 2012 (UTC)

User warning
Please do not attack other editors, as you did at Talk:Golden ratio. Comment on content, not on contributors. Personal attacks damage the community and deter users. Please stay cool and keep this in mind while editing. Please refrain from referring to your fellow wikipedians as "ignoramuses". Thank you.  Sparkie82 ( t • c )  20:55, 3 March 2012 (UTC)
 * If you think I was attacking you or any other editor, you need to re-read what I actually wrote. I was discussing the level of content of the article and the hypothetical mathematical abilities of *readers* of the article. —David Eppstein (talk) 21:05, 3 March 2012 (UTC)

Uriel Frisch
Hi David,

I would say he is quite notable, see the first item here, and this. More formally, he is a member of the French academy, and received quite a few different prizes.

Best, Sasha (talk) 19:23, 4 March 2012 (UTC)
 * Yes, he definitely looks worth keeping, and there's enough there that I can write something about him despite his work not being in my area. I'll add him to the list of articles I'll be creating as part of this cleanup. Thanks for pointing out this omission. —David Eppstein (talk) 20:02, 4 March 2012 (UTC)
 * I wrote a stub, here. Sasha (talk) 23:42, 5 March 2012 (UTC)
 * Thanks, I just put some effort into expanding it. —David Eppstein (talk) 01:21, 6 March 2012 (UTC)
 * "some effort" is an understatement, you septupled the article at least. Sasha (talk) 01:28, 6 March 2012 (UTC)


 * FYI, I remember an interview with John Kemeny (perhaps in Mathematical People) where he mentioned that Einstein only hired mathematicians as assistants---because Einstein needed no help with physics!
 * Kiefer .Wolfowitz 17:16, 6 March 2012 (UTC)

A barnstar for you!

 * You're welcome, and thanks for the barnstar! —David Eppstein (talk) 23:15, 5 March 2012 (UTC)

File:Mutually-inscribed-pentagon.png listed for deletion
A file that you uploaded or altered, File:Mutually-inscribed-pentagon.png, has been listed at Files for deletion. Please see the to see why this is (you may have to search for the title of the image to find its entry), if you are interested in it not being deleted. Thank you. Calliopejen1 (talk) 16:48, 6 March 2012 (UTC)

Freiman
Hi David,

following another redlink in the Erdos list, I have started writing a stub about Freiman, User:Sodin/Gregory Freiman. For now it's in my user space, since I have not found good references (for the mathematical part; there are plenty of references for his dissident activity). I think a good review should exist somewhere, but for now I have only found unpublished notes by Ben Green.

Best, Sasha (talk) 18:43, 6 March 2012 (UTC)
 * Freiman has 92 articles on mathscinet. "not found good references"??  132.70.4.119 (talk) 19:40, 6 March 2012 (UTC)
 * Well, but it would be better to find references by other people that say what his important discoveries are, rather than trying to figure that part out ourselves. —David Eppstein (talk) 19:59, 6 March 2012 (UTC)


 * Hi Sasha and David!
 * Freiman's Structural theory of set addition was translated into English by the AMS. Perhaps it has a forward?
 * I think that Asterique (or Obelix?) or another French journal (in blue) published a Freiman-friendly collection of articles on additive number theory in the last 10 years. Probably Nathanson has a paper in it. Nathanson's additive number theory (2+ volumes) probably discusses parts of Freiman's work.
 * The English translation of Freiman's samizdat memoir has a signed statement attesting to its veracity that was signed by about 20 of the most distinguished emigree mathematicians from the former USSR; that should count as a secondary source. Nathanson translated it into English, and it was published by Southern Illinois University Press, I believe; Abe.books.com should list some copies for bargain prices (e.g. John T. Zubal).
 * Best regards, Kiefer .Wolfowitz 20:13, 6 March 2012 (UTC)
 * thanks! it is Asterisque indeed. I will have a look in the evening. Sasha (talk) 20:59, 6 March 2012 (UTC)
 * still a stub, but moved to mainspace: Gregory Freiman.
 * Well done, Sasha! Kiefer .Wolfowitz 17:30, 25 March 2012 (UTC)

Regarding "Exponentially Large"
David,

I noticed that you have reverted my change to Dynamic Programming twice. While I agree that the reason that I gave for the change, in the one line edit summary, was inadequate, I did give a more detailed explanation in the page's Talk section.

Saying that a number is "exponentially large" tells us nothing about the number.

Saying that it is reasonable to call a number "exponentially large," because the number is "exponential in the size of the input" is equally nonsensical, because a number is neither a function nor a mapping of any kind. Is this conflation of concepts standard practice in Computer Science these days?

In the Talk page, I conceded that my change is minor, but logic and maths are founded on an endless list of minor and arguably trivial distinctions. See Is the Null Graph a Pointless Concept?.

I have made very few edits to Wikipedia, so I may have violated the community's mores. That said, I have to put my foot in the water some time. StandardPerson (talk) 05:46, 7 March 2012 (UTC)
 * If you don't understand asymptotic analysis, and in particular the fact that we can measure the behavior of computer programs using functions of their input sizes (that may sometimes in fact be exponential functions) then you have no business editing dynamic programming. —David Eppstein (talk) 06:05, 7 March 2012 (UTC)
 * (sorry for stalking.) I have rewritten the sentence, hopefully preserving content and adding some rigour (David -- please revert me if you think it became too technical). Sasha (talk) 06:23, 7 March 2012 (UTC)
 * Sasha, I certainly like the change! Thank you. StandardPerson (talk) 09:42, 9 March 2012 (UTC)
 * David, I apologise if my comment came across as excessively brusque; I thought I'd lightened the tone with the reference to the (very funny) Graph Theory paper. I do understand the concepts you've mentioned, 'though I have not studied them in particular. This time I've been replying in the Talk area, while you were replying here. Sincerely S.

StandardPerson (talk) 06:41, 7 March 2012 (UTC)

Hi David,

I just read the change you made to the beginning of Dynamic Programming and I certainly find it an improvement! I'm glad the result is something that (I hope) we're both happy with.

I would like to expand the current, extremely brief articles about the Lax_equivalence_theorem and Numerically_stable, but I suspect I should read the Wikipedia guidelines before weighing in, as I've just done.

Could you point me towards some guidelines about Wikipedia etiquette and the intended audience of Wikipedia articles? (Some articles are extremely specialised, while the articles that I mentioned previously are aimed at a broader, Encyclopaedia Britannica level audience.) Is there a general FAQ or discussion area, that you could point me towards? (After reading the Talk_page_guidelines I think this post is badly out of place, but I can't find somewhere better.)

Sincerely, S. StandardPerson (talk) 02:27, 9 March 2012 (UTC)
 * I think actually the change to dynamic programming was Sasha, not me. As for audience: I think the general principle is: make it accessible to as wide an audience as possible, but not wider. Some subjects (and Lax equivalence is probably one of them) are widely studied enough to be worth including but are just not going to be readable by someone with a non-mathematical high school level education no matter how hard you try. So you should err on the side of being correct and including the important material about the subject rather than dumbing things down to the point that you give incorrect definitions and leave important things out. For more detailed guidance, there's Make technical articles understandable or Wikipedia editing for research scientists. —David Eppstein (talk) 02:33, 9 March 2012 (UTC)


 * Thank you for those pointers and for your advice; it's most helpful. Regarding the stability of numerical methods and the L.E.T., all the various forms of numerical stability mentioned in the current article can be unified (in the linear case) using some beautiful papers by J. Sanz-Serna at the Universidad de Valladolid, which build on earlier, less rigorous work by Isaacson and Keller.


 * My suggestion does not involve dumbing things down. I'd like to assume the reader has some (second year?) background in functional analysis and use this to present precise definitions of the well-posedness of the exact problem, numerical stability, consistency and convergence to show the general (linear) statement and proof of the L.E.T. offered by Sanz-Serna. (M. A. Lopez-Marcos extended the linear framework to a quite general, non-linear one, so this approach is not just a sterile exercise in re-phrasing well-understood issues.)


 * From this solid foundation, further sections might show how the various definitions of numerical stability follow from the general one in various special cases. The advantage of this approach is that it shows that the "numerical stability" of the collection of approximate, discrete problems (with the collection indexed by a mesh size parameter) essentially amounts to the "uniform well posedness" of the collection, with uniformity required in the limit of the mesh parameter tending to zero.


 * Perhaps this is too specialised for an encyclopaedia article, but I keep thinking that it is no more so than many of the current articles about (e.g.) Quantum_Mechanics or Dynamic_Programming.  It would be a massive undertaking, but when I last checked the literature, I couldn't see a book or monograph along these lines.

StandardPerson (talk) 09:42, 9 March 2012 (UTC)

Disambiguation link notification for March 8
Hi. When you recently edited Ileana Streinu, you added links pointing to the disambiguation pages Degree of freedom and Rigidity theory (check to confirm | fix with Dab solver). Such links are almost always unintended, since a disambiguation page is merely a list of "Did you mean..." article titles. Read the FAQ* Join us at the DPL WikiProject.

It's OK to remove this message. Also, to stop receiving these messages, follow these opt-out instructions. Thanks, DPL bot (talk) 10:55, 8 March 2012 (UTC)

New articles

 * And thanks for the barnstar! —David Eppstein (talk) 16:57, 10 March 2012 (UTC)

Mathai Varghese
Hi David,

I have just noticed Mathai Varghese on the Erdos list, and I have a question. Apparently, Mathai is his last name, and Varghese &mdash; his first name (though the authors of the article refer to him familiarly as "Varghese"). What is the policy regarding this, are the articles named according to Western order (first name then last name), or according to the order common in the native language of the subject matter?

Thanks, Sasha (talk) 05:14, 15 March 2012 (UTC)
 * Apparently he uses Varghese Mathai on his papers (e.g. ) so that's what I think we should be using. If he were Hungarian I'd suggest also putting the eastern name order template on the article, but my guess from his name is that he's Indian (I have a co-author with the same name who is definitely Indian), so I don't know what the name order actually means. In some Indian subcultures they don't really have surnames, just the father's given name and then their own given name, and that may be what's happening here, but if so I don't know how to tell which one is which. —David Eppstein (talk) 05:29, 15 March 2012 (UTC)
 * he uses V.M. on his papers but M.V. on his site. I will look more carefully at the history of the article and either move it or suggest a move on the talk page, depending on what I see there.
 * Sasha (talk) 13:50, 15 March 2012 (UTC)
 * Actually, I had a closer look at the article, and it seems there are more urgent issues with it (e.g. there are no sources and notability is not obvious). It seems that the page is watched by a few editors, so I have marked it with an unsourced BLP tag for now. Sasha (talk) 14:01, 15 March 2012 (UTC)

Disambiguation link notification for March 15
Hi. When you recently edited Moti Yung, you added a link pointing to the disambiguation page PCWorld (check to confirm | fix with Dab solver). Such links are almost always unintended, since a disambiguation page is merely a list of "Did you mean..." article titles. Read the FAQ* Join us at the DPL WikiProject.

It's OK to remove this message. Also, to stop receiving these messages, follow these opt-out instructions. Thanks, DPL bot (talk) 08:33, 15 March 2012 (UTC)

Cheriyan–Mehlhorn/Gabow algorithm
Hi! Would you perhaps be able to help out Hal Gabow with the request he left at Talk:Cheriyan–Mehlhorn/Gabow algorithm and User talk:Ruud Koot? Regards, —Ruud 00:36, 21 March 2012 (UTC)
 * I don't have as much time for Wikipedia editing in the next couple weeks as I usually do (too many conference reviewing deadlines piling up, and exams to design and grade) but I can try to fit it in. —David Eppstein (talk) 01:08, 21 March 2012 (UTC)

Expander graphs
Hi David! I'd greatly appreciate your opinion on whether a certain statement in Expander graph constitutes Original_research. If you can share some time, please respond in the corresponding section on the talk page: Talk:Expander_graph. Thanks a lot! ylloh (talk) 02:22, 28 March 2012 (UTC)
 * Hello. Ylloh did not present the facts accurately. I suggest you reconsider your position, it's not a simple change in notation. --MathsPoetry (talk) 08:08, 28 March 2012 (UTC)