User talk:David Eppstein/2009c

Notability in Wikipedia

David, sorry to bother you with trifles, but you are the only wikipedian with serious credentials known to me. Can you please comment about a brand new article, Notability in Wikipedia, in talk:Notability in Wikipedia? Twri (talk) 22:39, 1 May 2009 (UTC)

Taxicab Geometry

David, you posted the following on the edit page:

"Hilbert's axioms are not a formalization of Euclid's axioms. They are a formalization of Euclidean plane geometry. And removing the wikilink is a bad idea. Silence ≠ consent"

There was silence because we have already discussed this with the other members. EVERYTIME I change it, it gets changed back. I had three people approve it, so I expect you to accept it. And what proof do you have? PLEASE LEAVE IT, AS IT GETS REALLY ANNOYING....THANK YOU! If you have ANY problems with this, PLEASE, PLEASE discuss it to me on my talk page, as I am SICK and TIRED of your unreasonable actions....

Rallybrendan2006 (talk) 23:27, 1 May 2009 (UTC)

By the way, the silence has been broken and I have gotten approval from Bubba72, so PLEASE respect that. See the discussion page for Taxicab geometry for proof. Thanks!

Rallybrendan2006 (talk) 23:49, 1 May 2009 (UTC)

Regarding: "Sorry, despite your CAPSLOCKS OF RAGE, I am going to change it anyway. Euclidian => Euclidean." ---- Fine. I can accept a minor spelling mistake. I just didn't want my correction to be removed again despite permission from the group....

Rallybrendan2006 (talk) 05:39, 2 May 2009 (UTC)

Ford circle

In your recent additions to the Ford circle article, I think item 1 should be

The circles C[r/s] such that |ps − qr| = 1

Otherwise, as currently written, it seems to say that all circles tangent to C[1/2] are also tangent to C[2/3] (because 2x2 - 3x1 = 1), which is incorrect.

Also, I don't fully understand item 3:

The circles tangent to C[r/s] where r/s is one of the two closest ancestors to p/q in the Stern–Brocot tree or vice versa.

For example, what are the "two closest ancestors" to 3/4 in the Stern-Brocot tree ? Are they 2/3 and 1/2 ? Or are they 2/3 and 1/1 ? Can you clarify your meaning here, please ? Gandalf61 (talk) 09:17, 3 May 2009 (UTC)

Thanks - your re-write is much clearer. Gandalf61 (talk) 08:03, 4 May 2009 (UTC)

Afd closed/reopened

Not sure if you'll care or if you should care. But figured you should know. [1] Bali ultimate (talk) 17:20, 8 May 2009 (UTC)

Blocked

You have been blocked from editing for a period of 1 week in accordance with Wikipedia's blocking policy for for repeatedly closing an AfD early. Once the block has expired, you are welcome to make constructive contributions. If you believe this block is unjustified, you may contest the block by adding the text {{unblock|Your reason here}} below, but you should read our guide to appealing blocks first.

—Preceding unsigned comment added by 24.61.10.180 (talk • contribs)

An IP can block people? This is a new one. —David Eppstein (talk) 17:35, 8 May 2009 (UTC)

LOL. That is one dumb IP. ResMar 17:41, 8 May 2009 (UTC)

DYK nomination of Calkin–Wilf tree

Hello! Your submission of Calkin–Wilf tree at the Did You Know nominations page has been reviewed, and there still are some issues that 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! Shubinator (talk) 21:00, 9 May 2009 (UTC)

Françoise Lebrun

Hi, Excuse me for my bad english. I see your work on Thierry Zéno page. Yesterday the page of Françoise Lebrun was deleted and I think it's a mistake because she's a french actress very famous in the little milieu of the post-nouvelle vague. She work with Jean Eustache ans Marguerite Duras. And Vecchialli. And many others... Can you take a look of this case? Thanks ! —Preceding unsigned comment added by 91.180.107.80 (talk) 21:09, 10 May 2009 (UTC)

I undeleted it, since the procedure by which it was deleted only requires a reasonable request such as the one you just made to be reversed. However, the article is in danger of a more permanent deletion unless published third-party sources can be found that are specifically about the actress rather than merely briefly mentioning her role as part of an article about some other movie. French-language sources are ok. —David Eppstein (talk) 22:20, 10 May 2009 (UTC)

Re: Françoise Lebrun

Fair enough, thanks for alerting me. –Juliancolton | ^Talk 22:23, 10 May 2009 (UTC)

Response

If she's so notable, when and where was she born? Carlossuarez46 (talk) 18:53, 11 May 2009 (UTC)

I have no idea. Why should we care — does that have anything to do with her accomplishments? —David Eppstein (talk) 18:55, 11 May 2009 (UTC)

DYK for Calkin–Wilf tree

On May 12, 2009, Did you know? was updated with a fact from the article Calkin–Wilf tree, which you created or substantially expanded. If you know of another interesting fact from a recently created article, then please suggest it on the Did you know? talk page.

Dravecky (talk) 13:49, 12 May 2009 (UTC)

Why http://en.scientificcommons.org is an unreliable source?

What do you say about DBLP?? --Kitresaiba (talk) 23:11, 14 May 2009 (UTC)

"Every researcher can organize his publication directly on ScientificCommons.org to create his own personal researcher profile." In other words, it appears to be self-edited rather than having any kind of centralized editorial control and oversight, so by Wikipedia standards it is a self-published source. DBLP, on the other hand, systematically collates contents of journals and conference proceedings rather than listing author-generated content. —David Eppstein (talk) 00:15, 15 May 2009 (UTC)

How about http://www.zentralblatt-math.org/ioport/ ?

It looks like DBLP does not include entries from jouranls - it takes just from conference proceedings. Google scholar looks ok in general. --Kitresaiba (talk) 00:39, 15 May 2009 (UTC)

Zentralblatt and MathSciNet are both reliable in the sense of WP:RS. However, what are you trying to use them to source? Indiscriminate lists of publications are not particularly useful in the articles here. —David Eppstein (talk) 00:41, 15 May 2009 (UTC)

MathSciNet is a good one. I do see you calling scientificcommons unreliable in Michel Deza the article I started with. But it listed all his work there. --Kitresaiba (talk) 01:17, 15 May 2009 (UTC)

Whether it has the correct information is a different question from whether it can be used as a reliable source. See WP:RS. —David Eppstein (talk) 02:21, 15 May 2009 (UTC)

Cellular Automata

It is not a requirement of cellular automata that the state transition function (your rule) be fixed. Indeed, one can easily conceive of rules that vary with time, or with context. I think your restatement is too restrictive. William R. Buckley (talk) 16:10, 15 May 2009 (UTC)

I have made adjustments to the opening paragraph of the Cellular Automata article, and request your review thereof. Justification for these adjustments is contained on the article talk page. William R. Buckley (talk) 20:31, 16 May 2009 (UTC)

Fáry's theorem

David, the year links (after Wagner, Stein, Fary) do not work, and I don't know how to fix these. Please correct these when you get a chance. Mhym (talk) 04:35, 16 May 2009 (UTC)

Fixed. To make this work the author= style of the citation templates needed to be changed to last= first=, and in one case the years didn't quite match correctly. —David Eppstein (talk) 04:44, 16 May 2009 (UTC)

New section on "Robust measures of scale" page

Thanks for your additions to Robust measures of scale. However, can you check whether you included the correct reference, and whether you have correctly characterized it as a technique for "multivariate data." From the paper it's pretty clear that they are proposing a method for univariate data. The first sentence says this explicitly, and the examples are all univariate. Skbkekas (talk) 14:26, 18 May 2009 (UTC)

Missing References tagging in MeshLab page

Hi David, I would like to clean up the MeshLab page that you just tagged with the unref tag. What kind of refernces do you think that should be added? Most of the information present on the page came directly from the home page (that is referenced) of the project and/or from their release notes. Do you think that it should be correct to add release notes as references too? ALoopingIcon (talk) 13:09, 26 May 2009 (UTC)

No, what I intended was more third-party sources that talk about MeshLab in a nontrivial way, as WP:V and WP:N both require. Google scholar has quite a few papers that mention MeshLab, though I don't know whether there are any that are not themselves by the MeshLab authors that cover it nontrivially. If you can find a published review in a magazine, for instance, that would be great. —David Eppstein (talk) 15:19, 26 May 2009 (UTC)

Got the point. MeshLab is frequently cited on many blogs and other web based, self-published, media like blogs (wired ) and many other review sites (I even find a episode of a web tv citing it), but probably that they are not completely reliable sources. Looking at 'printed' material I have only found a paper of the MeshLab authors describing the system (ercim news) and some academic papers by various authors citing the use of MeshLab in various contexts (Cultural Heritage, face recognition, surface reconstruction, etc). So, probably, the only sentence that would be supported by reliable sources is "MeshLab is used in various universities and research labs for general mesh processing task". ALoopingIcon (talk) 00:08, 28 May 2009 (UTC)

Shige Peng

This is a new bio on a Chinese mathematician and could use some attention from a specialist. Cheers, --Crusio (talk) 16:54, 29 May 2009 (UTC)

I'll take a look. An invited lecture at the ICM is a high honor so my presumption is that he's notable. —David Eppstein (talk) 18:18, 29 May 2009 (UTC)

I didn't doubt the notability, given the National Academy membership, but I was indeed not certain whether that invited plenary was worth mentioning. Thanks! --Crusio (talk) 16:56, 30 May 2009 (UTC)

DYK for Donald G. Fink

On June 1, 2009, Did you know? was updated with a fact from the article Donald G. Fink, which you created or substantially expanded. If you know of another interesting fact from a recently created article, then please suggest it on the Did you know? talk page.

Jamie^☆S93 20:21, 1 June 2009 (UTC)

Category

Mr. Eppstein, In all honesty, I'm not sure which category it falls under.Tyrenon (talk) 05:20, 2 June 2009 (UTC)

G works for me. Have edited what I'm putting in.Tyrenon (talk) 05:22, 2 June 2009 (UTC)

Fink rescue

		The Article Rescue Barnstar
		For rescuing Donald G. Fink from AfD, what was possibly my worst ever article (not counting the one with the opening sentence #redirect...) and well done on the DYK. SpinningSpark 15:12, 2 June 2009 (UTC)

You're welcome, and thanks for the barnstar! —David Eppstein (talk) 15:16, 2 June 2009 (UTC)

Nicholas Beale

There seems to be a recent major book in addition to the material there 2 yrs ago at the afd, so it's not really a G4. I think it would take another afd, and I'm not sure how i would !vote on it there. DGG (talk) 21:17, 3 June 2009 (UTC)

David Stack

• Would you take another look at the David Stack article and possibly change your Wikipedia:Articles for deletion/David Stack !vote? ty. --Firefly322 (talk) 00:50, 4 June 2009 (UTC)

P = NP problems

I should have stated my point more clearly from the beginning. Thanks for the edit. R.Vinson (talk) 07:16, 4 June 2009 (UTC)

Electrical topology

David, I see from your user page that you have the expertise to be able to help with a problem that has been troubling me for a while. The article Topology (electronics) makes a link between electronic circuit topology and graph theory. Although the article in its current form is largely my work, the link to graph theory was there in the original stub and I have a bit of a problem with it. Vertex in graph theory is equated with the meaning of "node" in circuit analysis - so far so good. Edge in graph theory is equated with "branch" in circuit theory. This is ok if the branch contains one or more resistors or other two-pole devices. However, some electrical components have more than two poles (the transistor has three for instance) and there does not seem to be any way of incorporating that in graph theory. An "edge" is required that will join three or more vertices. So at least for now, I have limited the applicability to 2-pole components only. Is there a mathematical object in graph theory that can join three vertices? Do you have any other comments on this? SpinningSpark 17:48, 4 June 2009 (UTC)

Hypergraph, maybe? But it might be simpler to handle it by making both the nodes and the components count as vertices, and the wires linking them count as edges. I'm pretty sure I've also seen work (involving questions of routing) in which only the components were thought of as vertices, and the nets (wires and nodes between them) were thought of as edges (or hyperedges, in the case of a net linking three or more components). I don't know which of these points of view is preferred in the electrical engineering literature, though. —David Eppstein (talk) 17:55, 4 June 2009 (UTC)

Hypergraph seems to be a good bet, but it is a new concept to me so I will need to study it. Yes, for routing the routers and servers would be nodes (this is network topology) but I'm not sure that works for circuit analysis. A two-pole component is connected to two nodes and it does not make sense to put it in just one of them. Likewise, the node will be connected to several other nodes, but the component associated with that node is connected (in physical reality) to only one of them. As for which is preferred in electrical engineering, I don't know either, all my circuit analysis textbooks treat topology in a very superficial way, if at all, hence the poverty of references in the article. My main motivation for creating this article is I intend to write articles on the transformation of circuit forms into each other based on the work of Foster, Cauer & co and I wanted an article describing basic circuit forms I could refer to. As far as I know, graph theory does not feature in their work so I am beginning to wonder if the whole para should just be deleted as OR. SpinningSpark 23:59, 4 June 2009 (UTC)

By routing I meant designing the physical placement of the wires to connect the devices in a VLSI circuit. —David Eppstein (talk) 02:02, 5 June 2009 (UTC)

Surely each pole is a node, rather than each transistor, in VLSI routing problems? SpinningSpark 01:43, 8 June 2009 (UTC)

Iterated Mycielskians

The Mycielski construction applied to the graph with no edges gives indeed a graph with one vertex and no edges. However, applying the construction to the latter results in M₂ = complement of P₃. In consequence, subsequent M_i-s are not connected and their number of vertices and edges is different than stated. Mycielski in his paper of 1955 started with K₂. Piotr.rudnicki (talk) 23:46, 4 June 2009 (UTC)

Ok, fixed, I hope. —David Eppstein (talk) 02:22, 5 June 2009 (UTC)

Friendly note

We may have had our differences in the deletion page, but after checking you out (I'm sure you did the same), I have to admit that I am very impressed with your personal accomplishments. I salute you for you are truly a good example for others to follow. Tony the Marine (talk) 05:03, 5 June 2009 (UTC)

Life without death

I'll certainly make you an animation of any Moore neighbourhood rule you like, but could you provide the starting position as a png in which the pattern is mapped 1 to 1 as white live cells on a black background? Thanks. Do you want the gun/antigun yellow/green colour code or do you want black and white? --Simpsons contributor (talk) 21:35, 7 June 2009 (UTC)

Is this what you're after? Are the dimensions OK? --Simpsons contributor (talk) 02:56, 8 June 2009 (UTC)

Life without death.

Mark A. Kukucka

Mark A. Kukucka appears to be a semi-notable academic (see Mark A. Kukucka#Career). Since you are so skilled with finding sources for academics, are there any that would establish notability for Kukucha? Thanks, Cunard (talk) 17:48, 8 June 2009 (UTC)

request for drawing: lamination

Hi. I saw your excellent math drawings, so thought I'd be so forward as to request another of you. Would you mind drawing a picture of a lamination? This can be a lamination of the plane, which is simplest, I suppose, or, if you, for some reason, prefer, a lamination of some other surface, or of a three-dimensional manifold. It should not be a foliation, though: it should have a complementary region (or more than one) visible in the picture. Again, obviously, this is only if you have the time and inclination. Thanks so much for your consideration.—msh210℠ 20:05, 9 June 2009 (UTC)

I'll have to think about how best to draw this, and my time for the next couple weeks is limited, but I'll definitely think about doing this. There is already a bit of a lamination in train track but I suppose you want a more complete example. —David Eppstein (talk) 21:11, 9 June 2009 (UTC)

Thanks. Yes, I was thinking that the density of the leaves in the image you'd make would be like the density of the leaves in the bottom half of File:Track-lamination.svg. (I'd make it myself (doubtless not as well as you can, but I wouldn't bother you for it), except that I don't know how to make many closely-spaced parallel curves in any editor.)—msh210℠ 21:36, 9 June 2009 (UTC)

And another I'd like to request, if possible, is a picture of a Murasugi sum. Thanks again for your consideration.—msh210℠ 18:25, 27 July 2009 (UTC)

Life without Death

Hi there - just thought i should drop you a message and admit that I made some not-very-supportive comments re this nominated article at DYK. I looked at it, and a related article (Puffer train), and I really couldn't understand them at all. I don't doubt that the refs check out and they make sense to someone in the field, but speaking as a lay person (albeit with a somewhat-rusty honours science degree), I couldn't grasp what was being explained. Sorry I can't be more help except to encourage the writing of new non-technical introductions to this cluster of articles. Regards. hamiltonstone (talk) 06:28, 11 June 2009 (UTC)

Yeah, I sounded grumpy on the DYK talk page, didn't I? Wasn't intended. You made some good changes, and I've been and made some more. I've ticked it for DYK but suggested some alt hooks if you want to check it out. Cheers. hamiltonstone (talk) 01:28, 12 June 2009 (UTC)

Philomena, Duchess of Vendôme

Hi. I'm letting you know about this suggestion since you participated in the AfD. Best, Olaf Davis (talk) 17:19, 11 June 2009 (UTC)

DYK for Life without Death

On June 13, 2009, Did you know? was updated with a fact from the article Life without Death, which you recently nominated. If you know of another interesting fact from a recently created article, then please suggest it on the Did you know? talk page.

Mifter (talk) 05:28, 13 June 2009 (UTC)

Run-on sentences

In mathematics, the Butcher group, named after the New Zealand mathematician John C. Butcher, is an algebraic formalism involving rooted trees that provides formal power series solutions of the non-linear ordinary differential equations modeling the flow of a vector field. It was Arthur Cayley, prompted by the work of James Joseph Sylvester on change of variable in differential calculus, who first noted that the derivatives of a composition of functions can be conveniently expressed in terms of rooted trees and their combinatorics. In numerical analysis, Butcher's formalism provides a method for analysing solutions of ordinary differential equations by the Runge-Kutta method. It was later realised that his group and the associated Hopf algebra of rooted trees underlie the Hopf algebra introduced by Dirk Kreimer and Alain Connes in their work on renormalization in quantum field theory.

It doesn't take a PhD in mathematics to recognize that this is poorly written. The only edit I've ever made to the contents of that article was this one [2] breaking the first sentence into two, inserting a paragraph break, trimming some unencyclopedic wordiness and improving the lead by removing a dangling preposition. Before you question my fitness to edit an article, I'd appreciate it if you actually looked at the article and edits in question. Cheers. ChildofMidnight (talk) 22:23, 24 June 2009 (UTC)

Thanks

Thanks for fixing my mistake there. I haven't closed an AfD in a while. Lәo_(βǃʘʘɱ) 21:23, 1 July 2009 (UTC)

No problem. I'm not sure the formatting of old afds makes a lot of difference in the long run, but I wanted to make sure that The Wubbot didn't get confused by the formatting, whenever it comes around again to archive the old AfDs from the deletion-sorting pages. —David Eppstein (talk) 21:27, 1 July 2009 (UTC)

About: Frank Duckworth AfD and Tony Lewis AfD

I noticed you commented on the Frank Duckworth AfD. I withdrew the appended Tony Lewis deletion. It now has its own deletion discussion page. See User_talk:Shirt58#Frank_Duckworth_and_Tony_Lewis for why this had been added to your talk page.
--Shirt58 (talk) 12:00, 2 July 2009 (UTC)

Graph isomorphism problem

I made a link for important source, so there is no real conflicts, and so your ref. to WP:COI is invalid for this case, it is your unproved suspicion only.You must prove COI before reverting in talk page!--Tim32 (talk) 19:14, 5 July 2009 (UTC)

I don't see why I "must" do any such thing. We've long since hashed this out in detail on the talk page. —David Eppstein (talk) 19:41, 5 July 2009 (UTC)

No, we have not! -- We discussed another statements for another article at long time ago. And so currently (17:24, 24 June 2009) Verbal had written "Reverted 1 edit by Tim32; I don't see a problem with the refs. Please discuss on talk. (TW)" And I wrote my arguments on talk page: the fact is that today only graph canonization approach for chemistry is noted in "Graph isomorphism problem"(Applications section). This is extremely incomplete! And I have the link to improve the article. If you can find any better link -- do it, but you should not offend me by unreasonable suspicion about WP:COI. This is defamation, before your proof of this your suspicion.--Tim32 (talk) 12:43, 6 July 2009 (UTC)

Please be careful throwing around words like "defamation" — using legal threats is a blockable offense here. —David Eppstein (talk) 16:11, 6 July 2009 (UTC)

You claimed that my edition is interesting for me only (and so there is COI), it is false. Your unproved claim may give negative image of my person. However, you MUST assume good faith -- it is a fundamental principle on Wikipedia WP:AGF. And as always you have no reason against my arguments which arguments I listed in previous message here.--Tim32 (talk) 22:53, 6 July 2009 (UTC)

Sheesh…

Hi, D.E.. Take a look here and here. —Scheinwerfermann ^T·_C14:12, 10 July 2009 (UTC)

…and especially here. —Scheinwerfermann ^T·_C05:15, 11 July 2009 (UTC)

Discussion with another admin about Tim32's link

Hello David. I briefly mentioned your name in this discussion at KC's page. If you have an opinion, you are welcome to add it there. EdJohnston (talk) 16:10, 10 July 2009 (UTC)

Diana Merry

Just a note to say good work - I was the one that PRODded the article, and it looks notable now.VsevolodKrolikov (talk) 07:37, 15 July 2009 (UTC)

Polyhedral combinatorics

Can you verify my fix at Polyhedral combinatorics? I came across the problem of bounding "V" in terms of "F" when preparing to teach the simplex method, and asked Carl Lee about it. He pointed out the cool result of Steinitz and some of his notes on it for non-major freshmen. I think I managed to fix two errors (a flipped inequality in 2e vs 3f, and a flipped fraction 1-2/3 = 1/3 not 1/2; listed as three in the edit summary, but the second error was just repeated twice). However, I tend to be a complete idiot when it comes to anything geometrical, so I'd appreciate a second pair of eyes on it. I have checked that every convex polyhedron on wikipedia does satisfy 0.5v < f < 2v, so I am pretty sure the old f < 3v was wrong (at least by the time you get to Steinitz's converse result). JackSchmidt (talk) 12:40, 15 July 2009 (UTC)

Looks good. —David Eppstein (talk) 15:07, 15 July 2009 (UTC)

recent afd

the ed who nominated Steven Gubser is an active member of Physics Wikiproject, rating articles for importance. It might be well to check his work.,DGG (talk) 08:21, 20 July 2009 (UTC)

Bagram Air Base to Bagram Airfield

I have a bit of justification for bringing this to the board, if you know somewhere else other than WP:RM please let me know.

If you take look further into the discussion and take a look at the talk page (Talk:Bagram Air Base) in question there has been three attempts at having the name changed. The problem I'm having that I could only reduce to speaking with an administrator or the collective as a whole is there has been quite a bit of support in the move along with detailed information regarding the name to be incorrect. The article conveys a wrong name and even confuses a reader by informing them the installations real name only to continue the use of inaccurate name. I don't feel I as an editor trying to bring factual accurate information can properly convey the correct name and other content when the article and its contents informing them of the wrong name.

I respectfully request you to take a look at this again before passing it off as the wrong place or doesn't need administrator assistance -- It has been brought up on WP:RM twice now (with a third discussion.. usually failing due to a "Common usage" policy that doesn't apply when factual references show it is simply wrong.) For this particular instance I will refer to WP:IAR as the common usage policy degrades the articles worth. -JE (Let's talk) (My contribs) 17:52, 22 July 2009 (UTC)

In other words, you disagree with what the people at WP:RM take to be the consensus so now you're forum-shopping? —David Eppstein (talk) 17:57, 22 July 2009 (UTC)

I'm simply trying to improve the article. Yes, I disagree, as do others. I'm perplexed at how hard it is to get a factual change made. I have no reason to 'forum-shop' and I only lightly edit. I'm not here to build some presence; only to contribute. I see something wrong, I found facts that back it up along with others, and now I'm trying to correct it. I would hope you can see where I'm coming from. -JE (Let's talk) (My contribs) 19:19, 22 July 2009 (UTC)

Notability (academics)

Hi, I've been asked to delete the request I made here [3] and I think I will delete it, but since you've commented I wanted to ask if you minded if I deleted your comment or if you want me to copy it to the talk page of the Tucker article or if you want to make the same point there. Thanks.Noirtist (talk) 17:22, 24 July 2009 (UTC)

I don't mind if you delete it. —David Eppstein (talk) 17:37, 24 July 2009 (UTC)

Done. Thanks. Noirtist (talk) 22:38, 24 July 2009 (UTC)

MSE

As you kindly gave advice earlier, I would like to let you know that I have reopened Wikipedia:WikiProject Mathematics/A-class rating/Maximum spacing estimation. Thank you. -- Avi (talk) 15:37, 31 July 2009 (UTC)