Wikipedia talk:WikiProject Mathematics/Archive/2007/Sep

message: Uncertainties of the limits, a recently created math article (without categories, so not found by the bot — I just added one) has been listed for deletion. —David Eppstein 15:48, 3 September 2007 (UTC)
replies: text: I've redirected it.  It was a badly written article on a topic worthy of inclusion by long-established consensus, and there was an already existing article. Michael Hardy 18:38, 3 September 2007 (UTC)
thread_title:  Another math article on AfD 

message: :User:WAREL is adding seriously wrong information to Riemann hypothesis again.
: is making almost sensible, although clearly incorrect, edits to Function (mathematics) and Grammatical function.
:I've reverted 3 times already today in each.  (45 in Function (mathematics), but the last two waswere clear vandalism.)  — Arthur Rubin |  (talk) 00:46, 5 September 2007 (UTC)
replies: text:  I blocked User:218.133.184.93 for 24 hours. Arthur, I understand your hesitation in blocking the guy (as a person involved in the edit conflict at that article), but next time if you (or anybody else) sees him doing the thing he's been doing for the last year or so, he should just be blocked on sight. I think there will be full support from the community here. Oleg Alexandrov (talk) 01:04, 5 September 2007 (UTC)
replies: text:  How funny, no real number ε is known to make that hold?  You'd think ε = ½ would be easy enough to prove, both functions being bounded by 0 and x.  Yeah, I think a block has to happen. CRGreathouse (t | c) 14:57, 5 September 2007 (UTC)
thread_title:  More possible vandalism in mathematics articles. 

message: I am wondering whether :Category:Fuzzy logic should be added to the list of mathematics categories. This would have the effect that all articles in this category would be listed in the list of mathematics articles by the bot.
So the question is, is fuzzy logic math? The answer could be a bit fuzzy, I guess. :) At the core it may be math, but it has a lot of applications outside math, and for example, Fuzzy electronics could not be considered math. Comments? Oleg Alexandrov (talk) 20:19, 4 September 2007 (UTC)
replies: text: There is a recent proposal that WP:LGC keep two worklists, one philosophy, and one mathematics. The fuzzy logic category is proposed to be among the mathematical logic categories. Gregbard 22:26, 4 September 2007 (UTC)
replies: text: Fuzzy is not logic. Fuzzy is not mathematics. (Although it might be a technique in control theory.) To the extent that it pretends to be logic or mathematics, it is a scam, a fraud. It would be more accurate to call it an attempt to destroy logic rather than logic. JRSpriggs 04:18, 5 September 2007 (UTC)
replies: text: Huh ? I am not an expert, but I have always had the impression that fuzzy logic is either a sub-topic or possibly a generalisation of the perfectly respectable mathematical subject of modal logic. Indeed the term "fuzzy modal logic" throws up a lot of academic-looking hits on Google. Am I mistaken ? Could you expand on your comments, JRSpriggs ? Gandalf61 10:48, 5 September 2007 (UTC)
replies: text: It seems that fuzzy logic has multiple meanings. I think of it mostly as a topic in control theory. In that guise it's an important tool in engineering but has had little to no impact on mathematical logic. The study of modal logic in mathematics is also quite small, although present; modal logic is usually studied by philosophers. — Carl (CBM · talk) 12:50, 5 September 2007 (UTC)

text: That seems a bit harsh, JRSpriggs.  A lot of the probabilistic variables used in models in eg cluster analysis, or data compression and transmission, strictly speaking are actually fuzzy variables -- ie Bayesian variables whose "true" value would still not be definitively known, even given a complete physical description of the state of the universe.  And recognising this can sometimes be useful.  Where "fuzzy logic" becomes much more questionable is in its many ad-hoc prescriptions and rough-and-ready shortcuts for manipulating such variables, which to Bayesian eyes generally look chancy at best, and often significantly wrong-headed.  Nevertheless, fuzzy approaches are widely used in model making, and calling them "not mathematics" seems, shall we say, a bit strong!  -- Jheald 13:31, 5 September 2007 (UTC)
replies: text:  Fuzzy logic gained critical attention when it was used in a rule-based artificial intelligence expert system for medical diagnosis, MYCIN, designed at the teaching hospital of Stanford University under the direction of Ted Shortliffe. The entry in the Stanford Encyclopedia of Philosophy may be helpful reading. Serious mathematical content exists. Compare to catastrophe theory, where perfectly respectable mathematics drew kookie attention because of a catchy name. --KSmrqT 13:24, 7 September 2007 (UTC)
replies: text:  Well, for now I put fuzzy logic in non-math, for practical reasons, since it has plenty of non-math articles and the potential to add more non-math to the list of mathematics articles. Perhaps some of the articles in that category could be put in :Category:Mathematical logic, and :Category:Fuzzy logic itself could perhaps be better categorized in :Category:Logic rather than in :Category:Mathematical logic. Oleg Alexandrov (talk) 02:35, 8 September 2007 (UTC)
thread_title:  Is fuzzy logic math? 

message: I notice this is a requested article in Wikipedia:Requested articles, I can't decide whether to make it a redirect to Fourier transform or Fourier analysis, or is this not a real technique after all? Help and advice requested. Thanks Tim Vickers 23:48, 8 September 2007 (UTC)
replies: text: The term is used with two very different meanings. One meaning, current in spectroscopy, diffraction analysis, and such, is conventional Fourier analysis & synthesis or Fourier transforms applied to the difference of two signals (see e.g. here). I don't think a simple redirect would address its significance. A quite different meaning is found in quantum algebra, as in the maths preprints found here.  --Lambiam 05:28, 9 September 2007 (UTC)
thread_title:  [[Difference Fourier]] or [[Difference fourier]] 

message: I request Maths people to review the article.  "In mathematics, Brahmagupta is considered the father of arithmetic, algebra, and numerical analysis." Sentences like this are not supported. 59.91.253.97 04:08, 9 September 2007 (UTC)
replies: text: I removed this sentence and the next two ones. As has been the case for a long time, the articles on Indian maths could use some attention from somebody who knows this stuff. -- Jitse Niesen (talk) 07:39, 9 September 2007 (UTC)
thread_title:  [[Brahmagupta]] 

message: Integral has been going through a significant collaborative effort, and is emering in a good shape. It should not take too much additional work (I'll add a few comments to the article's talk page) to get it to WP:GA. However, the article is in the middle of a thick web of interlinking articles on measure theory and various types of integral. Unfortunately these "surrounding" articles are often overlapping, use differing conventions, and certainly do not form a coherent set of articles. As the area of measure and integration is nevertheless fairly "compact", it seems quite feasible to edit the key articles refereced to / from Integral into better shape. I've been doing some minor fixes every now and then, but a more thorough effort of putting some structure on the set of these articles is what I think is needed. With the other articles in better shape, it would be also feasible to condence Integral in some places, making references to the more specialised articles instead of reproducing (quite as much) material in slightly different form.
The articles that I have in mind are (at least): Lebesgue integral, Riemann integral, Multiple integral, Line integral, Surface integral, Differential form, Green's theorem, Stokes' theorem, Fundamental theorem of calculus, Measure (mathematics), Lebesgue measure, Haar measure, Radon measure, Borel measure, Riemann-Stieltjes integral, Lebesgue-Stieltjes integral, Daniell integral, Lp space, Measurable function.
Sorting out these articles should in particular help make the structure of Integral clearer as regards the somewhat different if interlinked themes that it covers:
# Integral in the sense of measure and integration: the quest for more "general" integrable functions, different weights through measures or (in some cases) the Stieltjes method; integration on more general spaces than R ("multiple integrals" is hardly a "generalisation" anymore after the introduction of general measure-theoretic integral); spaces of integrable functions; improper integrals; and
# Line integrals, surface integrals, integrals of differential forms, Green's / Stokes' theorem
With such number of articles involved, and given that the whole topic seems to get emotional at times, I think the only way to do a more significant overhaul is to discuss it first here and only then start implementing. I'd be happy to develop and propose a more concrete plan for discussion if there is interest in such an effort. Stca74 11:25, 9 September 2007 (UTC)
thread_title:  Integral and surrounding articles 

message: I just wanted to ask some of you to check out the Principles and Standards for School Mathematics article and give your thoughts. Back in February a redlinked user removed significant amounts of content from the article.  Just wondering what your thoughts are on the article.--Jersey Devil 06:51, 10 September 2007 (UTC)
replies: text: Looking over it again it seems that the two users who had made most of that content were disruptive sockpuppets. However, it is still surprising that there is no mention on that article of the debate over "standards based" mathematics.--Jersey Devil 06:54, 10 September 2007 (UTC)
thread_title:  Principles and Standards for School Mathematics 

message: The academic year is beginning in the United States, which will probably lead to an increase in IP vandalism from students at computer labs during the school day. There are only three math articles currently semiprotected from editing by IP editors and new editors: Actuary, Mathematics, and Space. We have had problems in the past with vandalism of other articles such as Geometry and Randomness. If you notice an article is getting enough vandalism to warrant semiprotection, contact me or another admin to ask about it. — Carl (CBM · talk) 13:13, 5 September 2007 (UTC)
replies: text: And just to repeat myself, one can track the changes to the math articles from the list of mathematics articles (now with a link to all the changes  combined in one page). Oleg Alexandrov (talk) 14:59, 5 September 2007 (UTC)
replies: text:  I just semi-protected Dependent and independent variables for a week. I don't understand why just that article gets so many useless edits. -- Jitse Niesen (talk) 03:09, 12 September 2007 (UTC)
thread_title:  Article protection at the beginning of the school year 

message: This guideline is being discussed at Wikipedia talk:Notability with suggestions that it be deleted or merged into a single guideline for everything. --Bduke 07:00, 11 September 2007 (UTC)
thread_title:  [[Wikipedia:Notability (numbers)]] 

message: Hello. I have started a wikibook entitled The Book of Mathematical Proofs on the english wikibooks. It can be used to complement wikipedia articles by containing the proofs of the stated theorems. Please help in expanding the wikibook. In case of any questions kindly send me a message either on my wikipedia account or on wikibooks. Cheers--Shahab 17:54, 9 September 2007 (UTC)
replies: text: I seem to recall that Wikibooks specifically reported they did not want mathematical proofs?  Am I mistaken?  Did this change?  — Arthur Rubin |  (talk) 22:35, 9 September 2007 (UTC)
replies: text: I have specifically asked a wikibook administrator this question and he has given me the go ahead for the book. Also certainly saying that mathematics is all about proofs was a  mistake. Cheers--Shahab 06:57, 13 September 2007 (UTC)

text: I don't remember that, but if it's true, it seems like a huge mistake. You can't possibly write a textbook on any interesting mathematics without including proofs. Perhaps some people were creating 'books' containing just one proof, and that was being objected to? That would make more sense. --Sopoforic 22:40, 9 September 2007 (UTC)
replies: text: Thinking it over, it may have been wikisource, rather than wikibooks.  But it might be a good idea to check, first.  I seem to recall that some of "our" (Wikipedia's) mathematical proofs were moved to another Wiki, and then deleted from there.  — Arthur Rubin |  (talk) 23:21, 9 September 2007 (UTC)

text: Wikibooks are supposed to be textbooks. Does it make sense to aim at a textbook of all major theorems (and some not so major ones) in Algebra, Analysis, Applied Mathematics, Discrete Mathematics, Geometry, Logic, Mathematical Physics, Number Theory, Probability, Set Theory, Statistics, and Topology? Mathematics is not all about proofs, but at least as much about concepts and interconnections, which are needed to give the theorems context – so in the end you are creating an encyclopedia of Mathematics.  --Lambiam 23:22, 9 September 2007 (UTC)
replies: text: To be fair, mathematics is also about proofs, and there have been published math books similar in some ways to the concept behind this one: Aigner and Ziegler's Proofs from the Book, notably. —David Eppstein 03:02, 10 September 2007 (UTC)
replies: text: I wrote "Mathematics is not all about proofs" – and not "Mathematics is not  at all about proofs". Since the thread originator wrote: "Mathematics is all about proofs!", I think it's fair to point out that there are other important aspects. Proofs from THE BOOK definitely did not aim to present all major theorems in mathematics, something that makes the envisaged endeavour rather incomparable.  --Lambiam 10:42, 10 September 2007 (UTC)

text:  Not strictly on the topic of this discussion, but I disagree that Aigner and Ziegler, which is full of chefs d'œuvre that any mathematician will savour, is about proofs: it is about THE BOOK (orig. cap.) Arcfrk 03:31, 10 September 2007 (UTC)
thread_title:  From wikibooks 

message: I made an  so that Real number#R for Rn notation can be linked directly from its use, e.g. in Leech lattice.  The notation really needs some kind of explanation for those unfamiliar with it, but is this the best way to do it? ←BenB4 15:46, 12 September 2007 (UTC)
replies: text: Possibly a footnote at the end of the sentence would be better: something like "Here Rn denotes n-dimensional Euclidean space."  I've been using a similar approach for set-builder notation. Jim 16:11, 12 September 2007 (UTC)
replies: text: As I was going to do that, I thought, that would be a pretty small footnote. I'm happy with using a few words to explain it inline and linking. ←BenB4 20:42, 12 September 2007 (UTC)
thread_title:  Explaining R^n notation 

message: I'm having a disagreement with another editor on Talk:Null space about the introduction to the null space article, and we could use an outside perspective.  Thanks in advance, Jim 01:19, 14 September 2007 (UTC)
thread_title:  Null space introduction 

message: I could not find a Wikipedia article about the spectral analysis in this sense. I think spectral analysis is not quite what I have in mind. (Igny 16:28, 14 September 2007 (UTC)
replies: text: There's an article on spectral theory, which I found by going to the spectrum of an operator article.  (There's also an article on harmonic analysis, though I don't know how related the two fields are.)  I've changed spectral analysis to a disambiguation page. Jim 17:04, 14 September 2007 (UTC)

text: the content of the spectral theory article probably is something closer to what Igny had in mind than what an operator theorist would now call spectral theory, which begins with models and decompositions of operators. Mct mht 00:11, 15 September 2007 (UTC)
thread_title:  Spectral analysis 

message: ...is worth a look. --Trovatore 00:17, 15 September 2007 (UTC)
replies: text: For future visitors of this page: Wikipedia:Today's featured article/September 15, 2007.  --Lambiam 01:13, 15 September 2007 (UTC)
replies: text: Congratulations! Well deserved, I think... Geometry guy 15:52, 15 September 2007 (UTC)
replies: text:  That's great! Thanks to everybody involved. Oleg Alexandrov (talk) 03:05, 18 September 2007 (UTC)
thread_title:  today's featured article... 

message: There's a proposition (graphism thesis) that hard sciences use more graphs than soft sciences.  A paper once found that mathematics use less graphs than natural sciences.  If the proposition is correct, then that paper's results could be useful in a discussion of whether mathematics is a science.  Perhaps the topic should be discussed in Philosophy of mathematics or maybe in  the Mathematics article itself.  I added a sentence to Philosophy of mathematics, but I think more input is required.  Ideally we should find someone who has expertise in graphism...  Could you help me find out more about the implications of graphism in the question of whether maths is a science and locate more references in academic papers and the Web? NerdyNSK 17:04, 16 September 2007 (UTC)
replies: text: The actual conclusion of the second source is that hard sciences use graphs, soft sciences use tables. They reject the most obvious explanation, that the hard sciences have more quantitative information (although this is likely to explain at least part of the result on mathematics); but they say nothing about the other obvious reason: independent variables in physics are often quantitative; in sociology they often are not. (Another factor in mathematics is that mathematics is not limited to a small number of dimensions. Even Edward Tufte has trouble putting more than six dimensions in a graph.) Septentrionalis PMAnderson 18:43, 16 September 2007 (UTC)

text: *Also, the definition of graph being used includes a numerical scale, apparently on both axes. This would exclude diagrams, such as the subjects of graph theory, which are not uncommon in mathematical papers. As far as I can see, the proposed mechanisms for graphism should include these, however. Septentrionalis PMAnderson 17:29, 17 September 2007 (UTC)

text: **To be pedantic: graph theory is about a family of combinatorial objects that are not any more closely related to visualization of data than linear algebra is related to tables. The diagrams you describe are more properly the subject of graph drawing. —David Eppstein 17:35, 17 September 2007 (UTC)

text: ***No, I was merely not being pedantic; I meant, and mean, graphs, in the full mathematical sense; but a different term may be clearer to a philosopher. Septentrionalis PMAnderson 18:04, 17 September 2007 (UTC)

text: Graphs are more useful when the data is uncertain, such as in physical observations, than when it is known and described exactly, such as mathematical functions.  I doubt this hypothesis very strongly. ←BenB4 21:57, 16 September 2007 (UTC)
thread_title:  graphism 

message: Hi everyone!  I'd like to offer a tool for editing math articles.
Many math articles have HTML mathematics in them, e.g.
f: X × Y → [0, 1]
which displays as f: X × Y → [0, 1].  One of the disadvantages of this practice is that the HTML math might get broken between lines.  A common solution is to use non-breaking spaces:
f: X × Y → [0, 1]
However, this makes the code a bit unreadable, and it seems like there ought to be a better solution.  I looked into it, and eventually found a suggestion by grubber on the talk for the mathematics manual of style:
f: X × Y → [0, 1]
This is somewhat nicer, but still a bit lengthy, and hard to remember.  So I thought, why not make it a template?

I tried this (Template:Mbox), and it works nicely.  See User:Jim.belk/Sandbox for a demonstration.  The only disadvantage is that equals signs work strangely in templates, so you need to use |= instead of | for equations.  (It probably also gets confused if you try to use a vertical bar for absolute value.)  By the way, the name "mbox" comes from a TeX command that can be used to prevent line breaks in formulas.  It's possible that some other name (e.g. "hmath") would be better. Jim 03:59, 18 September 2007 (UTC)
replies: text: Looks good! Michael Hardy 04:42, 18 September 2007 (UTC)

text: Nice, but addresses the wrong problem. The real problem is that the rendering of LaTeX by wikimedia is bad. If Planetmath can do right, why not here. After wikimedia gets around to fixing the problem, we'll be all busy putting the LaTeX back where it belongs to get rid of the incorrect fonts and codes that were never meant to be used for math... Jmath666 06:17, 18 September 2007 (UTC)
thread_title:  mbox Template 

message: Two quite different statement on the same topic, both purporting to be Morera's theorem, have appeared in that article.  Reverted to the first version, which says if the integral of a continuous complex-valued function of a complex variable along any closed path is zero, then the function is holomorphic.  The second version said that if the function has an antiderivative, then it's holomorphic.  I've commented out the proof of the second version since that's not what's now in the article.  At talk:Morera's theorem there is some discussion.  I'm posting here in order to ask others to either join that discussion or work further on the page itself.  (So maybe that talk page (rather than this one) is the best place to say something about pros and cons of the two versions.) Michael Hardy 02:35, 14 September 2007 (UTC)
replies: text: Could we actually, like, approach this in a Wikipedia fashion? You know, citing sources that use Morera's theorem in some or other fashion? Abstractly discussing what the theorem might say is not what we should do, at least in the first instance. I have just added the EoM page as external link. Charles Matthews 15:16, 18 September 2007 (UTC)
thread_title:  "Morera's theorem" needs work 

message: Hi, I noticed that Journal of the Royal Statistical Society was on the User:Mathbot/Most wanted redlinks list.  This article is the first "collaboration of the week" for the Academic Journals project.  If you have any suggestions regarding this topic, or know of notable articles that have appeared in this journal, please join in the discussions on the project talk, or the talk page of the article. John Vandenberg 03:18, 21 September 2007 (UTC)
thread_title:  Journal of the Royal Statistical Society 

message: A heads-up about (I fear) the latest example of the WP box-ticking fetish. :Wikipedia:WikiProject Short article clean-up is devoted to making sure every article of five sentences or less has an explicit "References" section.  (An "external links" section doesn't count, but may get renamed). 
Editors are also encouraged to ask themselves whether the articles should be PROD'd / AFD'd / speedy deleted.
Yes, they could do some good; but the whole gung-ho project mission makes me feel uneasy, and I just hope somebody will keep an eye on them.  Projects like this can get out of control and start doing real damage, if people start instituting formalised requirements ahead of actual usefulness. Jheald 22:00, 19 September 2007 (UTC)
replies: text: I agree this is worrisome. Articles should grow and also add references naturally. Just mass slapping  indiscriminately or even complaining that an article has citations, but not inline, can be a bad idea. Hopefully those guys will use common sense and focus more on articles with disputed content rather than math stubs. Oleg Alexandrov (talk) 14:43, 21 September 2007 (UTC)
thread_title:  WP:SACU 

message: An anon contributor has repeatedly removed this animated image from the sphere packing article. He/she believes that it is distracting. I believe it is informative and improves the article. Does anyone else have views on this ? (Raising this here rather than on article talk page to get more attention and hopefully establish a quick consensus) Gandalf61 16:25, 21 September 2007 (UTC)
replies: text: I've commented there - I think the issue should be raised there too (to avoid what might be considered forum shopping - I know that's not what you're doing, but the discussion should be taking place over there). But I believe forcing the removal of that image without consensus is definitely not in the spirit of consensus-building. I also think there's nothing wrong with the image. --Cheeser1 16:58, 21 September 2007 (UTC)

text: Update: the user has violated WP:3RR, and I've issued a warning. The next reversion, if one comes, will prompt me to throw this one to the WP:AN/3RR. --Cheeser1 17:54, 21 September 2007 (UTC)

text: In a previous discussion, though I don't remember when, concerning animated images on pages, we decided that the best compromise was to replace the animation with a still shot and a link to the full animation, so that the motion was no longer intrusive on a casual reader.  Surely this will work here as well? Ryan Reich 19:06, 21 September 2007 (UTC)
replies: text: You're probably referring to Wikipedia talk:WikiProject Mathematics/Archive 24#Moving pictures and the Tesseract on our Project page.  --Lambiam 21:34, 21 September 2007 (UTC)

text: That would, of course, be a reasonable alternative. Of course, nobody provided a replacement image, nor did the user in question take the time to discuss the matter on the talk page. I think you'd do well directing your comments to the (seemingly more active) discussion at Talk: Sphere packing. Thanks for your input. --Cheeser1 20:36, 21 September 2007 (UTC)
replies: text: I've now done that here. While I like the idea of animations as a useful device, I often find them infuriating. Take the spiral on spheres in spiral. If you actually want to see whats happening the animations move too quick. The still frames in Rhumb line actually convay more information. --Salix alba (talk) 20:57, 21 September 2007 (UTC)
thread_title:  Animated image of sphere packing 

message: Planning statistical research has been nominated for deletion.  Post opinions at Wikipedia:Articles for deletion/Planning statistical research. Michael Hardy 15:44, 22 September 2007 (UTC)
thread_title:  "Planning statistical research" nominated for deletion 

message: I drafted a citation template  (or ) as an upgrade of  that can handle multiple links, and has some other extra features. 
For example, it can do things like 
:"The theory was developed by ", 
with links to multiple papers and to the authors. Feedback and bug reports can go to 
the talk page. R.e.b. 19:27, 23 September 2007 (UTC)
thread_title:  New Harvard citation template 

message: This short orphan article was nominated for deletion. I don't understand any of it, but I'm hoping that the members of this wikiproject will know enough to tell if the article is legitimate and the topic notable enough. Cheers,Itub 13:01, 24 September 2007 (UTC)
replies: text: There was a problem with the article, but it was fixed by an edit that occurred after the nomination for deletion.  However, I am not familiar with the subject matter, so I can't comment on whether the content would qualify it for deletion.  If someone familiar with Riemannian geometry could look at it, maybe that will be enough to settle the question. Michael Hardy 23:20, 24 September 2007 (UTC)
replies: text:  I had a look and commented on the article talk page. Should be a "keep" as far as validity of content. I'm not an expert on coarea formulae, but I suspect we'd eventually prefer to expand the article to cover a selection of them. --KSmrqT 05:10, 25 September 2007 (UTC)
thread_title:  [[Smooth coarea formula]] 

message: Can someone help keep an eye on multiplicative inverse, please? For some reason it's being persistently vandalized today (I already warned one anon and blocked another) and if I revert again it'll be my third. —David Eppstein 03:58, 25 September 2007 (UTC)
replies: text: Reverting obvious vandalism is exempt from 3RR. (But help is always nice; vandal fighting is tedious.) --KSmrqT 05:13, 25 September 2007 (UTC)
thread_title:  Multiplicative inverse