Wikipedia talk:WikiProject Mathematics/Archive/2017/Sep

Spring oscillation
A new article titled Spring oscillation is something of a mess at this point. Michael Hardy (talk) 17:02, 2 September 2017 (UTC)

Draft:Multi-objective linear programming
Input from WikiProject Mathematics members regarding the suitability of Draft:Multi-objective linear programming for article space would be appreciated. Several Articles for creation reviewers have suggested that the contents be merged to Multi-objective optimization, but the draft's author,, believes it would be better to have two articles. Your input would be helpful in reaching consensus. --Worldbruce (talk) 22:52, 2 September 2017 (UTC)

More eyes needed
Sharaf al-Dīn al-Ṭūsī, father of algebraic geometry - really??? --Bill Cherowitzo (talk) 21:10, 3 September 2017 (UTC)

List of mathematics competitions
Hello, folks. Last year, I proposed that the listing in the above-named article be drastically reduced, by removing all competitions that haven't been shown to be notable. That proposal is at Talk:List of mathematics competitions. No comments were received. I'm prepared to take action now on this, but will be happy to receive comments from this WikiProject before doing so. NewYorkActuary (talk) 03:25, 7 September 2017 (UTC)
 * Yes, please go ahead. None of the sources listed in the footnotes there look particularly significant or worthwhile, so my suggestion would be to keep all of and only the bluelinked entries. —David Eppstein (talk) 03:34, 7 September 2017 (UTC)

Lobachevsky integral formula
Lobachevsky integral formula might bear examination. Or might not? Michael Hardy (talk) 02:41, 9 September 2017 (UTC)

Gaussian integer
An edit war seems start at Gaussian integer. See also Talk:Gaussian integer. Other opinions are strongly needed. D.Lazard (talk) 13:38, 12 September 2017 (UTC)

Contravariant and Covariant Vectors
I have made a couple of entries on the talk page, but nobody seems interested and there has not been much article edit activity for a while. Could somebody have a look at the article and assess whether it needs attention. My opinion is that it could benefit from a thorough rewrite. The content is good, but wordy and disorganised, and the notation slightly distracting. I am prepared to put in some effort, but I don't want to stir up a hornets nest.Foucault (talk) 16:38, 15 September 2017 (UTC)
 * You mean Covariance and contravariance of vectors. Boris Tsirelson (talk) 16:54, 15 September 2017 (UTC)

Yes. Thankyou. I wrote this as an afterthought, when I was about to go to bed - 230am.Foucault (talk) 17:00, 15 September 2017 (UTC)
 * Note: I have reverted the edit and left a message at the article page. - DVdm (talk) 08:37, 16 September 2017 (UTC)

Geometry of an algebraic curve
I hope someone has an idea for what to do with this page. It reads like the backs of several envelopes. The title does not appear to be suitable (the material is much more narrow and esoteric than the title suggests, IMO); but before a better title can be chosen, the content needs clarification. XOR&#39;easter (talk) 23:07, 16 September 2017 (UTC)
 * It doesn’t really seem like an article on anything, just a collection of snippets on some topic, not necessarily the topic given by the title which seems too vague. I see this was raised on the talk page but was rejected with a "so fix it" argument, but with no proposal how it could actually be fixed and I don’t think it can be. AfD perhaps?-- JohnBlackburne wordsdeeds 23:50, 16 September 2017 (UTC)
 * WP:BLAR to algebraic geometry, maybe? —David Eppstein (talk) 23:56, 16 September 2017 (UTC)
 * That makes sense. The page history is still there for anyone who thinks they can do something with it. But as-is better a redirect until that happens.-- JohnBlackburne wordsdeeds 23:59, 16 September 2017 (UTC)
 * A redirect to algebraic geometry sounds good to me. XOR&#39;easter (talk) 00:27, 17 September 2017 (UTC)


 * Move back to the draftspace: I still think moving it back to the draftspace makes the most sense. There, it should be possible to work out what materials should belong to the draft with the current title. The error was to move it to the mainspace. The redirect makes little sense since it doesn't lead anywhere (i.e., people cannot work on it.) -- Taku (talk) 03:09, 17 September 2017 (UTC)


 * About the title. "Geometry" is there to compare it to arithmetic of algebraic curves, another important topic. -- Taku (talk) 03:11, 17 September 2017 (UTC)
 * I disagree with redirecting to algebraic geometry: almost everything in the article could be merged into Algebraic curve, and "Geometry of algebraic curves" refers clearly to algebraic curves, the first word being somehow a pleonasm. Thus I'll be bold and modify the redirect. D.Lazard (talk) 08:57, 17 September 2017 (UTC)
 * Oppose back to draft space: The move was already debated.  I would note that this would not be the first, second, third, or fourth time that Taku has tried to leverage this back into draft space to try and escape generally accepted operating procedures. IF the page can be improved, it can be done as a subsection of a larger article until such time that WP:SPINOFF becomes a useful solution to the parent article having too much content. Hasteur (talk) 23:10, 17 September 2017 (UTC)
 * It seems clear from the above that the move of the draft page to the mainspace didn't make sense. So the obvious solution is to undo that. -- Taku (talk) 00:11, 18 September 2017 (UTC)

RfC: Should the WP:TALK guideline discourage interleaving?
Opinions are needed on the following matter: Wikipedia talk:Talk page guidelines. A permalink for it is here. Flyer22 Reborn (talk) 18:41, 19 September 2017 (UTC)

X–Y–Z matrix
Is X–Y–Z matrix notable? Boris Tsirelson (talk) 06:22, 23 September 2017 (UTC)
 * I can't tell whether they really want to be talking about tensors or multidimensional arrays, but either way we have better material on the same subject. I don't think this article is a useful addition. —David Eppstein (talk) 06:43, 23 September 2017 (UTC)
 * From the grid mention, I suspect they are talking about multidimensional arrays. But the name is uncommon as far as I can tell. and the name ovelaps with transformation matrices to XYZ color space.It may not even be worth a redirect. --Mark viking (talk) 17:33, 23 September 2017 (UTC)
 * I'd say to redirect it to multidimensional array, but I'm not sure it's a sufficiently common search term to make that worthwhile. XOR&#39;easter (talk) 19:13, 23 September 2017 (UTC)

Maass wave forms
Someone (with a breathtakingly extensive deficiency of TeX skill) created an article titled Maass wave forms. I tried to move it to the singular, Maass wave form, and found that that was already a redirect to Maass cusp form. So I deleted the redirect and moved it. Should this new article, now titled Maass wave form, be merged with Maass cusp form? Michael Hardy (talk) 16:44, 23 September 2017 (UTC)
 * Why not? According to "Maass cusp form", these are two names of the same notion. Boris Tsirelson (talk) 19:39, 23 September 2017 (UTC)

Calculators and software in external links
I tend to be a bit fussy with external links and I see a lot of calculators in elementary articles (which I tend to remove) and software, either working programs or code, in CS articles (which I tend to leave alone hoping that someone else will deal with it). My feeling is that these things are not in the spirit of proper external links and they can usually be snagged on the basis of not being reliable sources. However, it would be nice (I think) if there was an explicit point addressing this issue on the list at WP:ELNO. Before proposing anything to a wider audience I thought that I would first like to gather the reactions of the members of this project, since it would affect us the most. If an outright ban is not in order then maybe some guidelines as to what would be acceptable could be given. Thanks for your consideration. --Bill Cherowitzo (talk) 23:13, 19 September 2017 (UTC)
 * I agree with this proposition. However, what is said about calculators can also be said of many external links to courses or mathematical explanations. These external links generally fall under item 11 (Blogs, personal web pages and most fansites) of WP:ELNO, but may also considered as aimed to promote their authors. Therefore I generally leave to the authors of the links the choice of the relevant item(s) by providing the edit summary "per WP:ELNO". Nevertheless an item on calculators and elementary courses would be useful. D.Lazard (talk) 08:36, 20 September 2017 (UTC)
 * I mean no insult to you. The idea that including math or CS theory in articles is acceptable, but that concrete instantiatons of the theory/algorthms, such as calculators and source code, are so far beneath us that they do not even merit an external link, however, strikes me as elitist. Especially in cases of source code links, these can be considered further development of the topic and a good alternative to trying to add source code directly to the article. Some encyclopedic books, like The Algorithm Design Manual, are valuable in part for thier curated lists of external links to source codes. Any of those source codes I would have no problem with externally linking. I think a proposal like this should emphasize whether the linked web site or source code is relaible or at least has been discussed/reviewed by third parties, rather than whether the content is theoretical or applied. --Mark viking (talk) 18:05, 23 September 2017 (UTC)

I am not sure how you are reading a theoretical vs. applied divide from the above comments. I am no stranger to coding and D.Lazard is certainly not either. Maybe I did not make myself clear enough, but my issue with calculators and code not being in the spirit of external links is precisely because we can not verify their reliability in any easy manner. There is absolutely nothing wrong with programs or code that have been properly vetted and they would make fine external links. However, I haven't seen this kind of vetting occur for the programs being placed on our pages, and that is what has me concerned.--Bill Cherowitzo (talk) 19:16, 23 September 2017 (UTC)
 * Thanks for your clarification. I interpreted your first two sentences in the original posting as that you were singling out and against all calculators and code in external links, in principle. With your clarification, I think we are in agreement that it is the reliability that is important for EL, not whether the content is a calculator, source code, tutorials, lecture notes, etc. --Mark viking (talk) 20:03, 23 September 2017 (UTC)
 * I tend to dislike calculators not because they are inaccurate (although that is also an issue) but because they don't add much to reader understanding of the topic (ELNO #1 — often they are just simple formulas that anyone could plug into a claculator), are typically very spammy (ELNO #5), have unknown provenance and little editorial control of their methods (ELNO #11) and often (especially for number-theoretic calculations) have significant limitations in the range of numbers that they can be used for (ELNO #16). —David Eppstein (talk) 20:15, 23 September 2017 (UTC)

Smooth projective plane
The article titled Smooth projective plane needs work. I found it as an orphan and I created two links to it in the "See also" sections of Projective plane and Real projective plane. Michael Hardy (talk) 16:35, 21 September 2017 (UTC)


 * Regretfully, these experts (main contributors) do not collaborate further. I wrote a number of questions there, but who can answer? Boris Tsirelson (talk) 07:25, 23 September 2017 (UTC)
 * A quote from myself (relevant or not): "if the only editor that wish and can to describe a topic here is the author, then probably the topic is not worth to be described here". Boris Tsirelson (talk) 20:48, 23 September 2017 (UTC)


 * As I mentioned on the talk page, I only helped to Wikify the page and this out of respect for the authors of the main reference whom I know only by reputation. The article does read like a research paper (or summary of one) rather than an article on a topic. Perhaps we should put clarification tags, corresponding to your questions, in the article and then PROD the whole thing in hopes of getting some attention to these issues.--Bill Cherowitzo (talk) 23:44, 23 September 2017 (UTC)

Redirect for Additive Combinatorics
The way this redirect is set-up doesn't really make sense, even though there is more info about the subject on the additive number theory page the redirect points to Arithmetic combinatorics. In fact, there is a loop formed by clicking on the words "additive combinatorics". On the Arithmetic combinatorics page it takes you to Additive number theory, on the Additive number theory page it takes you to Arithmetic combinatorics. I don't believe this should be the case, links for a given topic should always direct readers to the same page, in my mind. I don't have enough experience in the area to say where this information should actually be or which is right, but I do believe it should be straightened out. GiovanniSidwell (talk) 17:47, 27 September 2017 (UTC)


 * Thank you for pointing this out. This a redirect from 2008 and I suspect the arithmetics combinatorics article was probably the best target at the time. But I agree the section in additive number theory is in better shape, so I have redirected to Additive number theory. --Mark viking (talk) 21:16, 27 September 2017 (UTC)

Please Review my Article
I wrote an article on geometric mixed motives and I would like to have a mathematician on this site to review it. It was previously revoked by a non-mathematician, but their criterion for revoking the article is invalid: the sources I provided are notable. In addition, I made sure to cite other articles on wikipedia and gave detailed explanations on the page. Any help is appreciated! — Preceding unsigned comment added by 75.166.193.229 (talk • contribs)


 * Maybe these could help: "Geometric Mixed-Motives". Apparently not a huge subject, but the chances of approval increase considerably if you cite peer-reviewed publications. The sources you gave are, by definition, not notable or reliable. This has nothing to do with the meaning of the terms in the real world. YohanN7 (talk) 16:09, 18 September 2017 (UTC)
 * Why is the handbook of K-theory or the journal of K-theory not notable? One is published through Springer and the other is a peer-reviewed journal. — Preceding unsigned comment added by 128.138.65.89 (talk • contribs)
 * I have answered in the draft's talk page. D.Lazard (talk) 18:38, 19 September 2017 (UTC)


 * These are notable, however, up until yesterday they were so poorly referenced that this fact was hidden. You have to realize that in writing for an encyclopedia you can not assume that readers and even editors are going to be familiar with the perfectly good sources in your subfield. The publication data is needed to establish that these sources have been vetted by the mathematical community–just providing the links to these sources does not give that information. As I looked over your article I also noticed another problem that you will have. There are no in-line citations. The sources that you provide are meant to support the statements made in the article. Without the in-line links to the sources (including page numbers) the statements you make can not be verified by a reader and that is the heart of what Wikipedia is all about. If you keep at it this article will eventually be in good enough shape to be accepted. --Bill Cherowitzo (talk) 18:40, 19 September 2017 (UTC)


 * The content has now been merged into Motive (algebraic geometry). XOR&#39;easter (talk) 21:42, 27 September 2017 (UTC)

Merge Request
I think the Sheaf of logarithmic differential forms article should be merged into the Log structure or Logarithmic form page. What are people's thoughts? Username6330 (talk) 01:04, 27 September 2017 (UTC)


 * Umm, why? The notion of log differential forms makes sense and is still useful outside log geometry. I do agree to add some discussion how to understand this notion from the log-point-of-view. -- Taku (talk) 22:55, 27 September 2017 (UTC)


 * Logarithmic form is literally the same topic as Logarithmic form.  Sławomir Biały  (talk) 13:54, 28 September 2017 (UTC)


 * Sorry, I was questioning the merger with log structure (replace "why" -> "why log structure"). The two articles Sheaf of logarithmic differential forms and logarithmic form are on the same topic, obviously, and should thus be merged. -- Taku (talk) 01:32, 29 September 2017 (UTC)

Move discussion, possibly with wider implications
See Talk:Upper and lower bounds. There seems to be further inconsistency in article naming – when the title should have both a notion and its dual versus just one of them. I'm also not sure how it fits in with WP:AND, so I thought I'd see if anyone else had thoughts (the discussion there seems to have stalled). --Deacon Vorbis (talk) 14:13, 29 September 2017 (UTC)

Watchlist problem
Strangely, this day my watchlist page says "No changes during the given period match these criteria." which is surely wrong. Is it my personal problem? Do you see your watchlist normally? Boris Tsirelson (talk) 05:59, 29 September 2017 (UTC)

Never mind, it appears to be because of "Days to show in watchlist: 0" in my preferences->watchlist. I have no idea why this value was reset to 0, but anyway, I restored it. Boris Tsirelson (talk) 06:02, 29 September 2017 (UTC)


 * Honestly, I suspect the recent "improvement" on Watchlist filtering and display to be a possible cause for any trouble with "watchlist" you mention. OMG, what a remarkably sensible and fast and handy and ... user interface. Luckily I found the box where to check this off. Purgy (talk) 16:56, 29 September 2017 (UTC)

Complex analysis template up for deletion
For those that don't follow TfD, I note that Template:Complex analysis sidebar is up for deletion at Templates_for_discussion/Log/2017_September_27. It is up for deletion in part because this nav template is unused. Did it fall through the cracks and would be useful to add to complex analysis articles? Or is there a consenus to avoid such nav sidebars in this project? Thanks, --Mark viking (talk) 21:05, 27 September 2017 (UTC)


 * I don't know a reason not to use it. I suspect the only reason it's not used is lack of widespread awareness of its existence, and the reason for the lack of widepread awareness is that it's not used. Michael Hardy (talk) 03:11, 29 September 2017 (UTC)


 * Also, it's pretty new.  Sławomir Biały  (talk) 11:48, 29 September 2017 (UTC)


 * I boldly added the template under "See also" to the page Complex analysis. It is used now under its title, at least; so please, in case you are interested, check, if it disturbs or helps. Purgy (talk) 14:29, 29 September 2017 (UTC)


 * I've added it to a few more pages. XOR&#39;easter (talk) 14:48, 29 September 2017 (UTC)


 * WP:NAV suggests displaying sidebars more prominently (like at the top). I'll go ahead and move them there for now then.  --Deacon Vorbis (talk) 15:12, 29 September 2017 (UTC)


 * Fine by me. XOR&#39;easter (talk) 15:38, 29 September 2017 (UTC)


 * I do not know how these sidebars display on mobiles, and how easy some get annoyed by being molested with links they are not interested in, at least not at the moment. That's, and because I do not care much for WP:MOS, why I put it under "See also", where unsolicited links fit best, imho. But I do not really mind any place, or if employed at all. BTW, I aligned the pics with the sidebar. Purgy (talk) 16:45, 29 September 2017 (UTC)
 * Navboxes and sidebars (at least when they are built using the proper templates like navbox or sidebar) don't get displayed on mobile devices. – Uanfala 20:17, 29 September 2017 (UTC)


 * The navigation bar is not a new idea (see Template:Lie groups for a nice example). But this seems to need an improvement; I think it's too big (can be problematic in the mobile setup); this problem can be mitigated by the use of collapse. Also, the choice of the items looks strange (do we need a link to real number?) while some key theorems are missing, like uniformization theorem, Runge's approximation theorem and one-single-variable version of Cousin's first and second problems (Mittag-Leffler's theorem?). Finally, no need for the deletion. -- Taku (talk) 20:35, 29 September 2017 (UTC)