Wikipedia talk:WikiProject Mathematics/Archive/2006/May

message: The other day, I left a pretty extensive comment on Talk:Knot theory, in response to two editors who complained about the article's tone.  One specific complaint was the use of pronouns and that the article sounded like a teachger giving a lesson.  Now, I just noticed that Braid group has been tagged (by someone else) with a "tone" tag, and the talk page mentions for example, that the use of "we" is bad and that it sounds too much like a "math lesson instead of an encyclopedia".    
My thought is that while some of the pronoun use could be favorably excised, I am definitely starting to get the feeling (especially after examining the articles in question) that these particular editors do not understand the conventions in mathematical writing, e.g. "We consider blah as doing blah..." is ok.  They also may not understand that sometimes a procedural description should be given, e.g. "take such and such and do such and such...".  See my long comment linked above.  I would like to know what those who normally work on mathematics articles think about all this, so please drop by those pages and make some comments. --C S (Talk) 03:58, 1 May 2006 (UTC)
replies: text: We is pretty much mathematical jargon; one is better for the general reader. Charles Matthews 11:45, 1 May 2006 (UTC)
replies: text:  I believe the passive is the preferred thingy. "We consider..." becomes "... is considered". --MarSch 14:08, 1 May 2006 (UTC)
replies: text:  But then... "is considered", er, by whom? By a deity? (Igny 15:33, 1 May 2006 (UTC)
replies: text: This reflects a certain diference about using We. In a statement like We can deform a knot in 4D it can easily be rewitten as a knot can be deformed in 4D and the prounoun can easily be dropped. However We consider... are subjective statments and in a paper the we is used to indicate the opinion of the authors. In wikipedia such subjective statements need appropriate qualification most mathematicians consider 4D knots to be very boring. --Salix alba (talk) 19:04, 1 May 2006 (UTC)

text: I've responded where requested; see for details. Passive is not preferred; just the opposite. Overuse of "one" also makes reading drag. Technical writing has a tradition of such conventions, not to its credit. --KSmrqT 19:15, 1 May 2006 (UTC)
replies: text: A MIT style guide says to use "we" in the active voice. I see now that I was mistaken in thinking it too personal, and yes, I did not understand mathematical writing conventions as pointed out by Chan. I will try to not be an ignoramus in the future. --Reader12 03:57, 2 May 2006 (UTC)
replies: text: Well, you live and learn!  I tried to carefully explain how the situation appeared to me without being patronizing or rude; I hope you weren't offended.  At any rate, I think it's been a very fruitful discussion thus far with a variety of people voicing their thoughts and it's still ongoing!  --C S (Talk) 08:08, 2 May 2006 (UTC)
replies: text: No, no offense taken. This has been very instructive to me. Thanks! --Reader12 21:40, 2 May 2006 (UTC)

text: I've just come across a great book on Algebraic topology by Allen Hatcher which can be downloaded . To my mind he has a very good writing style, which avoids the problems of overly technical writing, whilst still being technically correct. I fell there is quite a bit which could be learnt by examining how he structures his writing. I think a lot of illustrations help, the sub project /Graphics has reciently been set up to try to improve the illustrations of the maths articles. --Salix alba (talk) 09:21, 2 May 2006 (UTC)
thread_title:  "Tone", pronoun use, etc. in math articles 

message: The poster deadline for wikimania is fast approaching. I think it would be really good if we could have some presence there as a step to getting meta:Blahtex integrated into the main encyclopedia sites. Neither User:Dmharvey or myself are able to attend, but posters can be submitted without having a physical presence. Questions: is anyone here planning to go to wikimania Aug 4-6, in Cambridge MA? Anyone happy to spend some time standing next to a Blahtex poster? For those who don't know Blahtex is a extension which converts LaTeX maths into the MathML XML markup which allows for improved rendering of mathematics in MediaWiki with moder browsers. --Salix alba (talk) 10:05, 2 May 2006 (UTC)
thread_title:  Blahtex and wikimania 

message: Loom91 has been goaded by Melchoir into nominating "Proof that 0.999... equals 1" for deletion, on the grounds that Wikipedia should not contain proofs like this. The archives of sci.math currently show well over a thousand postings related to this topic, which is therefore included in the sci.math FAQ; yet it appears that Wikipedia covers the topic far better. Those who are interested can register an opinion here. Caution: This topic (and perhaps this vote) attracts, um, non-standard thinkers, to put it delicately. (See the talk page archives for examples ad nauseam.) --KSmrqT 10:31, 5 May 2006 (UTC)
replies: text: Yeah, I feel bad about that; sorry, everyone! (In my defense, though, I did try to explain why the AfD would fail, after which I didn't think Loom91 would actually go through with it.) Well, at least it's attracting some fresh constructive attention, and it'll be useful to have on record. Melchoir 20:09, 5 May 2006 (UTC)

text: That's a understatement; it closed with a speedy keep, with overwhelming support and complaints about the nomination as violating WP:POINT. --KSmrqT 22:31, 6 May 2006 (UTC)
thread_title:  Bogus AfD of proof article 

message: I rewrote the article Mode (statistics). Please review and correct errors, rewrite awkward sentences, simplify, embellish, supply sources, etc. It would further be nice to have some illustrations, both for a continuous density function and a histogram. LambiamTalk 20:40, 5 May 2006 (UTC)
thread_title:  Rewrite of [[Mode (statistics)]] 

message: Should this be kept, deleted, merged, or should there be a category of "mathematical formulas"? (I wonder what the morphisms would be.) Visit Wikipedia:Articles for deletion/List of Mathematical Formulas and contribute your two cents. LambiamTalk 21:04, 6 May 2006 (UTC)
replies: text: As far as I can see, the chemists don't need :Category:Formulas. We might not need it either, though. Charles Matthews 19:09, 7 May 2006 (UTC)
thread_title:  AfD for [[List of Mathematical Formulas]] 

message: See . I don't read Japanese so I can't tell if the change is correct, but it's exactly the type of change we might expect from WAREL if he came back. --Trovatore 15:24, 10 May 2006 (UTC)
replies: text: OK, I hate machine translation but it has its points. He changed the article to point to a nonexistent article on ja.wiki, called "Commutative field". It's WAREL alright; please block him with all deliberate speed. --Trovatore 15:41, 10 May 2006 (UTC)
replies: text:  blocked. -lethe talk [ +] 17:20, 10 May 2006 (UTC)
thread_title: WAREL back?

message: Just created the page on Stewart, James Stewart (mathematician), your contributions would be most appreciated.--Jersey Devil 09:08, 11 May 2006 (UTC)
thread_title: James Stewart

message: There is a discussion at the Village pump that might interest a few people here. —Ruud 01:09, 12 May 2006 (UTC)
thread_title:  TeX font size 

message: Is there anybody here interested in tackling the Koszul-Tate derivation topic listed on the "wikipedia:Articles requested for more than two years"? Thank you. — RJH 15:45, 12 May 2006 (UTC)
thread_title:  Koszul-Tate 

message: I wrote the following on Category talk:Mathematics; copying here.
An anon recently changed the Spanish link to :es:Categoría:Matemática from :es:Categoría:Matemáticas, or perhaps the other way around. It seems that both categories exist and are populated. Would someone whose Spanish is better than mine like to go tell them? I don't know how they handle these things over there; I think things like  are set up language-by-language. --Trovatore 14:54, 13 May 2006 (UTC)
replies: text: It looks like :es:Categoría:Matemática was created just today, by one :es:Usuario:Ingenioso Hidalgo, who then took it upon himself to go around recatting over a hundred articles, then apparently got tired. Unless this was discussed somewhere this doesn't strike me as good behavior; someone should let them know. I don't know if they have any equivalent to WikiProject Mathematics. --Trovatore 15:21, 13 May 2006 (UTC)
replies: text: On second thought, I suppose someone will notice, as the recats will surely show up on some watchlists. --Trovatore 15:35, 13 May 2006 (UTC)
thread_title: Spanish category

message: There is a discussion on decimal-style notation for p-adic numbers, and what would be appropriate to use, on the talk page Talk:P-adic number which we would like comments on. I added a section which uses a notation which is unusual but not unprecedented, in the section intended to convey the intuitive idea of a p-adic number. It seems to me the notation I used does that more successfully than any alternative for people used to decimal notation. Gene Ward Smith 21:14, 13 May 2006 (UTC)
thread_title:  P-adic numbers 

message: User:Oleg Alexandrov seems to me to be engaging in abusive reverts on this page, to a previous verison which is arguably incorrect mathematically and which removes a lot of new material, material for which he has given no argument for removal. He also says, falsely, that my attempt to satisfy his previous criticims amounted to "writing a one-liner" which seems to prove he hasn't even seriously looked at the version he is reverting from. I think we need other people to weigh in at this point. I am very much opposed to simply allowing it to say the real numbers have a number line and calling that a definition. My proposal to say they have a number line, with no "room" to fit additional numbers in, is an attempt to make the one-line introduction correspond to an actual rigorous definition, which will not be the case if we allow Oleg's revert. Gene Ward Smith 22:32, 13 May 2006 (UTC)
replies: text: Comments at talk:real number are encouraged. My version of things is that Gene is convinced enough that he is right that he is prefers repeatedly reverting to his version to discussing things on the talk page. Oleg Alexandrov (talk) 22:51, 13 May 2006 (UTC)
replies: text:  I think you need to take your own advice; your reckless reversion was done without any discussion. Gene Ward Smith 23:28, 13 May 2006 (UTC)
replies: text:  Regardless of who did what, there is a discussion running at the talk page now. Please engage yourselves there. -- 127.*.*.1 23:35, 13 May 2006 (UTC)
thread_title:  Real number 

message: User:CltFn has proposed to move Islamic mathematics to Middle-Eastern mathematics. Please comment at the talk page. —Ruud 02:36, 15 May 2006 (UTC)
thread_title:  [[Islamic mathematics]] 

message: On this page there is a box telling us that hyperreal numbers, superreal numbers, and surreal numbers are "complex extensions"; in fact, they are all real closed fields. Gene Ward Smith 04:34, 15 May 2006 (UTC)
thread_title:  Math error right on this page? 

message: Could someone take a look at zero-eigenvalue bifurcation? It is proposed for deletion, but it do find some uses of this term on google scholar. —Ruud 00:17, 16 May 2006 (UTC)
replies: text: The deletion, rather than redirection, seems summary and not necessary. Charles Matthews 11:03, 20 May 2006 (UTC)
replies: text: I agreed with the deletion because I think that the term "zero-eigenvalue bifurcation" is hardly used by itself (in constract to more complicated phenomena like the "double zero-eigenvalue bifurcation", used as a synonym for "Bogdanov-Takens bifurcation"). But if you want to create a redirect, be my guest. -- Jitse Niesen (talk) 13:07, 20 May 2006 (UTC)
thread_title:  [[Zero-eigenvalue bifurcation]] 

message: A debate is in progress at Talk:P-adic number about whether p-adic numbers should be written from right to left or from left to right. The article used to use the right-to-left notation, but was recently rewritten with the left-to-right notation. Contributions to the debate from a wider pool of wiki mathematicians would be helpful, to see if we can reach a concensus. Gandalf61 08:21, 16 May 2006 (UTC)
replies: text: Okay, after some discussion on its talk page, I have now changed the p-adic number article to consistently use the right-to-left notation, but with a new section that mentions other alternative notations. Any comments on the partial re-write are welcome at Talk:P-adic number. Gandalf61 09:34, 26 May 2006 (UTC)
thread_title: ''p''-adic numbers notation

message: I propose to delete the bits about Moore closure in the article Kuratowski closure axioms; see Talk:Kuratowski closure axioms#Moore closure. --LambiamTalk 09:05, 16 May 2006 (UTC)
thread_title:  Moore closure 

message: Sometimes an editor goes thru an article and changes many minor things at once.  For example: spelling corrections; deleting unneccessary spaces; replacing & alpha ; with α; etc..  When this is done, the function which shows changes in the history often fails.  It may begin matching an old paragraph to the wrong new paragraph and then it never gets back in synch (until one reaches a section header, if that was not changed).  Of course, this makes it very difficult to check that the change was done appropriately.
I think that it is probably impractical to correct this bug in the comparison.  So I am suggesting that you-all try to avoid this situation in the first place.  When you do such massive edits, please first do every other paragraph (to allow the software to get back in synch with an unalterred paragraph).  Then do a separate edit to change the remaining paragraphs.  Thank you.  JRSpriggs 06:06, 20 May 2006 (UTC)
replies: text: I think you'll need to provide a concrete example of this happening. Dysprosia 09:39, 20 May 2006 (UTC)

text: For this example it would have helped if the diff algorithm ignored blank lines, that is, tried to match up the two versions after filtering out the blank lines (which should be re-inserted for the final presentation). I suppose there is a backlog of all kinds of wishes for the developers, and I don't know how important this really is, but it is relatively simple to implement. --LambiamTalk 18:48, 21 May 2006 (UTC)
replies: text: I think that the problem is more difficult than Lambiam thinks it is.  In the section to which I referred, the only blank line was the next to last paragraph.  Yet the mismatching of paragraphs began at the first paragraph in the section.  Apparently the diff-software cannot measure the similarity of the contents of two paragraphs until after it has decided irreversably that they are matching paragraphs.  That matching of paragraphs appears to depend only on whether they are identical, followed by interpolation (guessing) between identical pairs of paragraphs. JRSpriggs 07:12, 22 May 2006 (UTC)
replies: text: Blank lines were removed in the edit following each and every section title. This doesn't show up clearly in the diff, but start an edit on both versions and compare the contents of the edit boxes, and it will be obvious. If then the next paragraph is also modified, the diff algorithm can't line them up. The silly thing in this massive edit is that many of the changes have no substance and consist of replacing two spaces after a full stop by a single space. --LambiamTalk 10:06, 23 May 2006 (UTC)

text: You may want to mention this on Wikipedia:Village pump (technical) or check the bugZilla where there are currently 93 bugs related to the diff. In this case the edit summary gives some clue, the edits were done using the  WP:AWB tool, they are mainly minor edits and it would be hard to break this up into smaller edits, by limitations of the software.  --Salix alba (talk) 07:16, 23 May 2006 (UTC)
replies: text: The problem is apparently caused by a feature of AWB, "Apply general fixes", which removes "excess white space" to which the diff algorithm is sensitive (Wikipedia:AutoWikiBrowser#"Set options"). --LambiamTalk 10:15, 23 May 2006 (UTC)
thread_title:  Massive edits foil comparison operation in article history 

message: I find myself in a revert war at the article dual space.  It's mostly about style; how much information is too much, whether material looks good or fits.  this diff shows the difference between the two users preferred revisions.  See also this old version for a much longer revision that I reverted.  I am pessimistic with how talks on the talk page are going.  We seem not to see eye-to-eye.  I would like to get some more opinions. -lethe talk [ +] 04:42, 23 May 2006 (UTC)
thread_title:  resolve a revert war at [[dual space]] 

message: Probabilists out there, I wonder if you could answer a question posted at  Talk:Compound Poisson process. Oleg Alexandrov (talk) 17:25, 24 May 2006 (UTC)
replies: text: looks right to me.  (and the changes i made were mostly cosmetic.) Lunch 19:10, 24 May 2006 (UTC)
replies: text: I added a final line to the moment generating function calculation, which should clarify matters further.  The variance result looks OK, by computing them in terms of the moment generating function.  — Arthur Rubin |  (talk) 20:27, 24 May 2006 (UTC)

text: ... and generally, the nth cumulant of the compound Poisson distribution, following the notation now in the article, is λt times the n moment of the distribution of the random variable that the article (in its present form) calls Di.  This can be shown via the law of total cumulance.  The cases n = 1 and n = 2 are just what now appears in the article. Michael Hardy 21:20, 24 May 2006 (UTC)
thread_title:  Compound Poisson process question 

message: Being a newcomer here, I would appreciate some brief advice: Lebesgue spine is listed somewhere as a missing link, but when I look at 'what links here', I only find things like Wikipedia:Missing science topics/Maths16. I could write a page about the Lebesgue spine, but would it be any use? Madmath789 20:35, 25 May 2006 (UTC)
replies: text: Sure it would be useful. Paul August ☎ 02:45, 26 May 2006 (UTC)
thread_title: Lebesgue spine

message: OED lists "non-negative" but Webster's lists "nonnegative".  Is this a British/American usage split?  I've looked through a few textbooks, but there doesn't seem to be any particular consistency (not all American books use "nonnegative" and not all European ones use "non-negative").  Any opinions?  There seems to be a mix among Wikipedia articles (even within a single article) and titles.  Thanks.  Lunch 22:05, 25 May 2006 (UTC)
replies: text: I use either when the mood strikes me.  If there's no standard, what's the difference? Ryan Reich 22:39, 25 May 2006 (UTC)
replies: text: I s'pose I was thinking consistency would make things easier to find, and any source I found was always self-consistent whereas the Wikipedia isn't.  And now that I look through the textbooks sitting in front of me, four have "nonnegative" (five American authors) and only one has "non-negative" (two Frenchmen).  Lunch 23:11, 25 May 2006 (UTC)

text: In my experience, in American papers and textbooks "nonnegative" is by far the most common. Older works may use "non-negative" to a greater frequency.  --C S (Talk) 01:52, 27 May 2006 (UTC)
thread_title: Non-negative v. nonnegative

message: Most of the references I've seen have a symbol over the "C", which I can't figure out exactly how to generate.  (Also, there seems to be a convention that the "-" should be replaced by an n-dash "–".)  — Arthur Rubin |  (talk) 00:28, 26 May 2006 (UTC)
replies: text: How about this: Čech? Dmharvey 02:51, 26 May 2006 (UTC)
replies: text:  When I open an edit window, below the Save page button is a box that says "Insert:", followed by numerous special characters. The character in question is one of them, and clicking on it causes it to be inserted into the edit box. JavaScript must enabled in the browser for this to work. --KSmrqT 03:52, 26 May 2006 (UTC)

text:  What a mess. We have Stone-Cech compactification and Stone-Čech compactification, and Čech points to neither, and probably we need Cech as a redirect as well. Dmharvey 02:56, 26 May 2006 (UTC)
replies: text: Hm, apparently the redirect at Stone-Čech compactification is my fault; don't really remember doing it. Stone-Cech compactification should be moved to Stone-Čech compactification, but it won't let me move it because the redirect is to a different place. I'll tag the redir for speedy. --Trovatore 03:05, 26 May 2006 (UTC)

text: OK, fixed now. This time the endash thing came in handy. --Trovatore 03:12, 26 May 2006 (UTC)

text: Added. Hey, you never know. --Trovatore 22:34, 26 May 2006 (UTC)
thread_title:  ''Stone-Cech compactification'' name 

message: A certain User:Mathguru has AfD'd Quasi-Hopf algebra and Quasi-bialgebra. I think it is notable, but as the author, I may be biased.Blnguyen | Have your say!!! 06:39, 26 May 2006 (UTC)
replies: text: I'm a hair away from closing them both speedy keep. -lethe talk [ +] 10:48, 26 May 2006 (UTC)
replies: text: Too late now ... I closed them. -- Jitse Niesen (talk) 12:00, 26 May 2006 (UTC)

text: Also closed as a speedy keep. -- Jitse Niesen (talk) 08:36, 31 May 2006 (UTC)
thread_title:  Maths AfDs 

message: Don't pages like this, Derivative (examples), break with WP:NOT?--Jersey Devil 02:32, 27 May 2006 (UTC)
replies: text: I have put it up for afd, your input would be appreciated.--Jersey Devil 02:36, 27 May 2006 (UTC)
thread_title: Indiscriminate collection of information?

message: Ladies and Gentlemen! Did you know that the article Mathematics is the current Article Improvement Drive collaboration? --LambiamTalk 22:40, 27 May 2006 (UTC)
replies: text: Voted for it on the AID page. One user commented that it is in the top ten most viewed pages on Wikipedia and therefore must be a featured article.--Jersey Devil 23:01, 27 May 2006 (UTC)
thread_title:  Mathematics is Article Improvement Drive collaboration 

message: The article Eventology (by the same author as Widespread mathematical delusions) has been nominated for deletion. --LambiamTalk 13:21, 28 May 2006 (UTC)
thread_title:  Eventology AfD 

message: I've nominated the article Delusions in probability theory and statistics (earlier called Widespread mathematical delusions) for deletion. --LambiamTalk 22:31, 28 May 2006 (UTC)
thread_title:  Delusions in probability theory and statistics on AfD 

message: There are two possible definitions of the sinc function, namely
:\operatorname{sinc} \, x = \frac{\sin x}{x} \quad\mbox{or}\quad \operatorname{sinc} \, x = \frac{\sin \pi x}{\pi x}. 
One possible way to handle this is to split the article sinc function in two, sinc function (normalized) and sinc function (unnormalized), similar to the usual disambiguation process. We are having a discussion on Talk:Sinc function (unnormalized) whether this is the proper way to go about it, and I'm solliciting others to join. -- Jitse Niesen (talk) 05:21, 31 May 2006 (UTC)
thread_title:  Disambiguation of sinc function 

message: There is an article Subadditive which discusses functions satisfying f(x+y)\leq f(x)+f(y), and there is a link to this article from Sigma additivity in the category measure theory. There seems to be a different definition of 'subadditive' (and also 'countably subadditive') in use in measure theory:
:\mu(E \cup F) \leq \mu(E)+\mu(F)
(used in developing the theory of 'outer measure'). My question is: do we need a separate page for subadditve set functions, or should we incorporate it into the existing subadditive page? (Or are subadditive set functions not notable and we do not need them?). I might be in a position to write something on the set function version of subadditive (if needed), but would appreciate some views about what might be done - and there are probably others better qualified to write such stuff anyway.Madmath789 11:27, 31 May 2006 (UTC)
replies: text: I think you're right, subadditive (measure theory) deserves its own article. I don't know any measure theory, but I recall there being interesting theorems about set functions which are additive (on finite collections of sets) and countably subadditive. Dmharvey 11:37, 31 May 2006 (UTC)
thread_title:  Possible confusion over 'subadditive' 

message: The piece on Barry Simon is from a fan, it seems. Important guy for mathematical physics, and this should be better expressed and sourced, and have more technical stuff about the work. Charles Matthews 11:46, 31 May 2006 (UTC)
replies: text: A good example of hagiography I guess. --CSTAR 18:54, 1 June 2006 (UTC)
thread_title: Barry Simon article