Wikipedia talk:WikiProject Mathematics/Archive/2015/Jan

Watchlist bug
Is it only me experiencing that this page does not always show up on the watchlist? YohanN7 (talk) 07:03, 25 December 2014 (UTC)


 * My guess would be that when Wikipedia is busy changes to a page take some time to be reflected on your watch-list. I doubt that updating watch-lists is the top priority of the system. JRSpriggs (talk) 12:29, 25 December 2014 (UTC)


 * Updating watch-lists is obviously one of the main priorities of the "system". It relates directly to user experience. I also didn't ask if my observation is important. I asked if anyone else has seen it. YohanN7 (talk) 11:31, 26 December 2014 (UTC)


 * I have not noticed it. But it is unlikely that I would since I rarely look at this page except as a result of it being on my watch-list.
 * The experience of the general user (who is not an editor) would probably be a higher priority than that of an editor. Only editors are likely to use watch-lists. JRSpriggs (talk) 14:39, 26 December 2014 (UTC)
 * Editors are likely to be online browsing, reading and editing 100 times more than mere readers per month Just to make clear what is annoying with this bug: I frequently have to type "Wikipedia talk:WikiProject Mathematics" in the search box. (I am a clumsy typist.) I know, I could create a link on my user page. YohanN7 (talk) 14:19, 28 December 2014 (UTC)
 * ...or just type WT:MATH in the search box :) No such user (talk) 18:08, 28 December 2014 (UTC)
 * Short for WikiTroject MATHematics? Wouldn't work. Wouldn't remember it from one hour to the next. YohanN7 (talk) 18:17, 28 December 2014 (UTC)
 * And WT:WPM, documented at the top of this page, has one letter less, and is hopefully more intuitive ;). No such user (talk) 10:58, 29 December 2014 (UTC)
 * I have a lengthy list of links at the top of my talk page (most editors put this list on their user page). One of them is a link to this page. So I could just click on the "talk" link to get to my talk page and then click on my link to this page. Easy. JRSpriggs (talk) 00:44, 29 December 2014 (UTC)
 * YohanN7, when you look at your watchlist, do you see a link that says "Show bots"? If so, that's your problem.  When your watchlist is set to "hide bots", then it hides any page whose last edit was performed by a bot—even if there were dozens of non-bot edits since the last time you looked at it.  You can change your watchlist settings permanently at Special:Preferences.  If you're the sort of editor who checks Wikipedia all day, every day, even when you're on vacation, then I recommend setting your watchlist to show everything, even bot edits.  Whatamidoing (WMF) (talk) 00:27, 2 January 2015 (UTC)
 * Thanks, but I have it set to "show bots". When the problem "happens" it is as if I don't have the page on the watchlist at all, even if it is listed in the watchlist, at least, when I go here after a few days suspecting that the watch feature has broken down, the watch-tab is still set to "on", and there may be several new posts on the page. I emphasize that this isn't a big problem, but I find it curious. It has been this way for some time, probably a year. It is browser-independent (IE/Chrome/Mozilla). It is exclusively this page that is affected. YohanN7 (talk) 00:40, 2 January 2015 (UTC)

List of matrix decompositions
Interpolative decomposition is a new article. Because it is an orphan, I thought maybe list of matrix decompositions should link to it. But that doesn't exist. Should it? Michael Hardy (talk) 22:45, 2 January 2015 (UTC)


 * Yes. -- Taku (talk) 00:39, 3 January 2015 (UTC)
 * There's an article, matrix factorization. YohanN7 (talk) 05:10, 3 January 2015 (UTC)

Quaternion rotation biradial
This is the one of the most extreme articles I have seen, It's too long to read, so I can't say anything except that I strongly doubt that it belongs in an encyclopedia. YohanN7 (talk) 18:33, 1 January 2015 (UTC)
 * The lead could be the lead of an article in Wikipedia, if a notable concept. The claim that Hamilton used it would not be sufficient for notability, even if verified. Perhaps it might fit in Wikibooks or Wikiversity.  — Arthur Rubin  (talk) 19:49, 1 January 2015 (UTC)
 * I agree with Arthur--the level of detail in the article is more appropriate for a monograph or textbook, so Wikibooks or Wikiversity seem reasonable destinations. Based on a quick GScholar search, the quaternion biradial is not a notable concept. The concept is perhaps worth a summary in Quaternions and spatial rotation. --Mark viking (talk) 23:53, 1 January 2015 (UTC)
 * This is a particularly egregious example of the walled garden of geometric algebra content on Wikipedia. It's been clear for awhile that this garden could do with some pruning, but someone really need to make it their mission to do that.  And, also, collaborate with the GA people too&mdash;some of them are a little wacky.  We do have some semi-active editors User:JohnBlackburne and User:Quondum who would probably be good at this, but who really has the time and patience for such a task?  I, for one, am willing to leave these things be.   Sławomir Biały  (talk) 00:38, 2 January 2015 (UTC)
 * Woo-hoo! It's so long, it is a mission just to scroll through it. My guess is that it is a transcription of a thesis or some papers or textbooks (the comments on the talk page seem consistent with this); it seems too far-ranging and detailed to have been freshly created from multiple sources as an article. My reaction is that it could be simply deleted, as I agree that it does not belong in WP as an article. It has been written recently (since April 2014), in its entirety, by a single editor.  I don't feel the impulse to do anything but point out to the editor that this sort of article is not what WP is about. —Quondum 04:33, 2 January 2015 (UTC)
 * Further to that it looks like one of the many things dreamed up in the 19th century which was superseded by geometric and/or matrix algebra when they were developed. It's worth a mention, as a stub-like article which acts as a brief reference for anyone looking for it, or within another article if one's found suitable. The rest just doesn't belong, at least not on WP.-- JohnBlackburne wordsdeeds 05:21, 3 January 2015 (UTC)
 * Yeah, it seems like this article should be deleted and/or stubified by someone who thinks they can do it justice. Rschwieb (talk) 17:12, 7 January 2015 (UTC)

- I have copied the above to the articles talk page and notified the creator. YohanN7 (talk) 22:09, 7 January 2015 (UTC) - Hello, I wrote the page from my own research, not as a thesis draft or anything like that. I am okay if the page is deleted, or torn into more than one wiki page, or whatever. I just felt like trying to contribute some information that might be useful. If it could be moved into a wikibook, that would be fine. I don't know how to make a wikibook, so if anyone wants to just do that, that would be great. Actually, I have anticipated that this kind of negative discussion would occur, and that the article would come up for deletion. I've just been waiting. Before deleting, just consider for a moment that the article does contain some valuable information. The article is large and ugly, but I think it could be very useful to some students trying to learn something about those quaternions and how they work in geometric algebra. The approach taken by explaining quaternions as the product or quotient of vectors is not found in many books. The article went a bit too far maybe, but what I added I felt was very useful to just dump there. The section on the "expansion of the geometric product of blades", something fundamental really but a bit advanced, is strangely enough something you can hardly find in any book, and where it is mentioned, it is still not explained well enough to be usable. Try learning the subject some before just deleting it, and maybe see that the article has something to offer. The page appears to be viewed very little according to the page view statistics, so it is mostly just sitting there causing no real harm to wikipedia yet has potential to provide info to someone searching for it. Twy2008 (talk) 19:37, 9 February 2015 (UTC)

Eyes requested on Catalan number
There is a small-scale edit war at Catalan number and I would be grateful if another editor would take a look at the recent edits there. Thanks. (I will probably not be able to make any substantive edits in the next 2 weeks or so.) --JBL (talk) 03:04, 8 January 2015 (UTC)

Wikipedia talk:Articles for creation/François Fages
Hello mathematicians. I have added some sources to this old AfC submission, and moved changed the self-references to publications. Is this a notable mathematician, and should the page be moved to mainspace? &mdash;Anne Delong (talk) 04:14, 9 January 2015 (UTC)

Help
Here is quote I have been having a hard time understanding in my research:

"Figure 4 shows the cumulative volume of erupted material versus time for the northern Cordilleran volcanic province; the slope is a qualitative measure of the overall rate of magmatism (km3/m.y.). Although the rate of magmatism has varied substantially through time, there is no correlation between the rate of magma production and the number of active centers during any interval of time (Edwards and Russell, 1999). Initially (20 Ma) volcanism was sporadic, producing small volumes of material. The eruption rate increased markedly (e.g., ~10–4 km3 yr–1) when volcanism began at Level Mountain at 15 Ma. When Mount Edziza began to erupt (ca. 7 Ma), rates of magmatism for the northern Cordilleran volcanic province increased to ~3 × 10–4 km3 yr–1 (Fig. 4). Between ca. 4 and 3 Ma a magmatic lull appears to have ensued; subsequently rates of magmatism have remained relatively constant at 10–4 km3 yr–1. Current rates of magmatism for the northern Cordilleran volcanic province are much less than those estimated for Hawaii (10–1–10–3 km3 yr–1; Shaw, 1987) or the Cascade volcanic arc (0.2–6 km3 yr–1; Sherrod and Smith, 1990)."

Can someone explain to me what these numbers mean (e.g. ~10–4 km3 yr–1) in a more simple format?  Volcano guy  02:14, 10 January 2015 (UTC)


 * In this context, "~" means "about" (roughly, approximately). "10–4" means one divided by ten four times, that is, $$\frac{1}{10\;000}$$. "km3" means cubic kilometres of magma, i.e. a billion (1 000 000 000) cubic metres (although usually not in the form of a cube, but spread out more horizontally). "yr–1" means "per year" (probably averaged over some lengthy period of time). So this example translates to "about 100 000 cubic metres of magma per year". JRSpriggs (talk) 11:05, 10 January 2015 (UTC)


 * Yes, in more commonly used units, 10–4 km3 yr–1 means that the volcano(es?) is releasing 100 million liters (or 26.4 million gallons) of matter (magma?) per year. FireflySixtySeven (talk) 11:45, 10 January 2015 (UTC)


 * Incidentally, there is the Reference desk/Mathematics, where questions of this sort will be answered quicker than here. It is usually also interesting to read other peoples questions and their answers over there. YohanN7 (talk) 19:34, 10 January 2015 (UTC)

Betti numbers and torsion coefficients
Hi,

I have started a discussion at Talk:Homology (mathematics) on how to present these topological invariants. All contributions gratefully received. &mdash; Cheers, Steelpillow (Talk) 13:56, 12 January 2015 (UTC)

Wikipedia talk:Articles for creation/Green's function number
Dear mathematicians: Is this old AfC submission about a notable topic? The references are not on line, but perhaps someone here at this project can tell if these are appropriate. &mdash;Anne Delong (talk) 17:29, 10 January 2015 (UTC)
 * This article has been accepted, but it still needs a bit of cleanup and some more references. Primefac (talk) 18:42, 10 January 2015 (UTC)
 * Thanks, Primefac. &mdash;Anne Delong (talk) 15:21, 12 January 2015 (UTC)

A resource for English-Chinese translation of high school math terms: "Bilingual Dictionary of Mathematical Terms: English--Chinese."
If anyone is...
 * Trying to translate mathematics content on the English Wikipedia into Chinese
 * Trying to translate mathematics content on the Chinese Wikipedia into English
 * Adding Chinese-language terminology to mathematics-related content on the Wikimedia Commons
 * Trying to hold a mathematics-related discussion with a Chinese user

I have a source you can use (as long as it's high school level math - about Algebra I/Geometry level)
 * "Bilingual Dictionary of Mathematical Terms: English--Chinese" (Archive; 英漢對照數學用語). New York State Education Dept., Albany. Bureau of Bilingual Education. 1988. -- See profile at (Archive) ERIC

There are also similar dictionaries for Vietnamese and for Laotian but unfortunately they are not online yet (both say "PDF pending restoration") WhisperToMe (talk) 13:42, 13 January 2015 (UTC)

WikiProject X is live!


Hello everyone!

You may have received a message from me earlier asking you to comment on my WikiProject X proposal. The good news is that WikiProject X is now live! In our first phase, we are focusing on research. At this time, we are looking for people to share their experiences with WikiProjects: good, bad, or neutral. We are also looking for WikiProjects that may be interested in trying out new tools and layouts that will make participating easier and projects easier to maintain. If you or your WikiProject are interested, check us out! Note that this is an opt-in program; no WikiProject will be required to change anything against its wishes. Please let me know if you have any questions. Thank you!

Note: To receive additional notifications about WikiProject X on this talk page, please add this page to WikiProject X/Newsletter. Otherwise, this will be the last notification sent about WikiProject X.

Harej (talk) 16:57, 14 January 2015 (UTC)

Wiki page for the equation of a forced pendulum?
I'm talking about the equation discussed by Hubbard in this overview (originally published in American Mathematical Monthly, so one would assume it is a topic of sufficiently general interest). There numerous non-wiki resources for it... On wiki, Duffing equation is similarly chaotic, but does not cover it.

Also driven pendulum redirects to Kapitza's pendulum, but that's not what 99.9% of the non-wiki sources usually mean by "driven pendulum", but rather what I linked in that pdf. 86.121.137.79 (talk) 22:26, 14 January 2015 (UTC)

AfC request
Could someone please give the page at User:Inezzzzz/sandbox a look over? I've asked at two other wikiprojects as well, but I can't even begin to understand what is happening at this article. -- T K K ! bark with me! 23:47, 15 January 2015 (UTC)
 * It seems to be a notable enough topic, but the wiki presentation is poor. In a (mathematical) nutshell: "Indicator kriging is ordinary kriging of indicator variables for several cut-offs." On the other hand there are several books detailing it, including psedudocode etc., so that a sub-article may be justified. But don't ask me to write it. 86.121.137.79 (talk) 06:53, 17 January 2015 (UTC)

Finite volume methods...
This came up on the current activity page, not new but newly categorised. and looking I found two more very similar: It's outside my area so I can't do much to them. They clearly need cleaning up but then what? Are they even notable, or just worked examples of the finite volume method? Or should they be merged, they certainly have a lot in common, not just names but similar content, similar extended links sections. Created by three different accounts, perhaps someone logging in after forgetting a password, perhaps lots of copy and paste.-- JohnBlackburne wordsdeeds 02:21, 21 January 2015 (UTC)
 * Finite volume method for three-dimensional diffusion problem
 * Finite volume method for one-dimensional steady state diffusion
 * Finite volume method for two dimensional diffusion problem

Please evaluate an AFC draft
Please evaluate Draft:Laver property for acceptability into mainspace. Roger (Dodger67) (talk) 18:10, 21 January 2015 (UTC)


 * The key sentence needs to be expanded or explained more. JRSpriggs (talk) 18:30, 21 January 2015 (UTC)
 * Is the expansion of that sentence essential for the article to pass WP:Notability? If not I can accept it into mainspace now so that normal maintenance can take care of it. Roger (Dodger67) (talk) 09:56, 22 January 2015 (UTC)


 * I do not know. I never heard of the Laver property before. If the Shelah reference is real, I would let it in, but I do not have his book so I cannot check it. JRSpriggs (talk) 14:36, 22 January 2015 (UTC)

Citing a preprint
(I am posting this here rather than at Wikipedia talk:WikiProject Polyhedra because that project is pretty well inactive.)

Johnson, N.W.; Geometries and transformations (2015) is actively being cited in many articles on polyhedra and related topics, in a sudden flurry of activity. writes on his talk page that it currently exists only in PDF preprint form but it has been accepted for publication. I have in my possession an earlier draft which was circulated many years ago, and just a couple of weeks ago began removing references to it which had appeared in many of these articles. Suddenly, these are being supplanted by references to the anticipated 2015 publication. Based on past history, I am not confident that the wait for publication will in fact be a short one. Are we happy to accept Tom's word on this? &mdash; Cheers, Steelpillow (Talk) 11:19, 6 January 2015 (UTC)


 * I've had PDF access to the manuscript since 2011 with its final draft submitted in March 2014, and accepted in September 2014, and is in process of being reformatted with minimal content changes. I agree a preprint is problematic on verifiability. I take full responsibility if there are delays in print dates, and I'll update all reference usages as needed on final publishing. I've tried to include exact references on specific facts, and sections and titles should be fixed, but cited page numbers will likely shift a bit. Tom Ruen (talk) 21:30, 6 January 2015 (UTC)


 * I see not so much a problem with citing a preprint to an expert, but rather that the preprint doesn't seem to be publicly accessible. A link to it might be a valuable addition, but not a reference that is only in private circulation.   Sławomir Biały  (talk) 12:50, 6 January 2015 (UTC)


 * I've looked into this a little more, and I don't think things are quite that simple. See, for instance, 8-demicubic honeycomb.  This reference has been there for a number of years, so presumably Tom Ruen relied on it to write the article.  Only recently does it seem that he has updated the dates on that reference, presumably in anticipation of its imminent publication, although we can't really be sure.  In an academic setting, it is necessary and appropriate to cite the sources that one uses, whatever their publication status.  That seems to conflict slightly with WP:V in this case.  However, I think we should allow the reference to stay there to avoid any appearance of plagiarism.  Hopefully it truly will be published soon, and this whole affair will become a non-issue.  Anyway, just my 2c, so YMMV.   Sławomir Biały  (talk) 13:27, 6 January 2015 (UTC)

I have the suspicion that a lot of the references on our polyhedra pages are pro forma "cite something generic on polyhedra because a Wikipedia article needs to have citations" rather than being specific to the subject of the article and the information they are supposedly sourcing. E.g. we have a lot of references to Coxeter's Regular Polytopes (a fine and relevant book) but without any page numbers or other identifying information that would tailor the reference to the article it appears in. So a preprint with a generic title that nobody can access is especially problematic, regardless of the reliability of its author. —David Eppstein (talk) 16:15, 6 January 2015 (UTC)
 * I agree entirely. I have noticed too that any challenge to some fanboy's favorite factoid tends to result in a flurry of such citations, typically also to self-published web material. There is much that needs attention. Now that we learn that Johnson's book is not yet in its final form but still being "reformatted with minimal content changes", I am even less happy about pretending on most every polytope page that it will be published this year. And what on Earth does it mean for a Wikipedia editor to "take full responsibility"? Whatever happened to biding one's time? &mdash; Cheers, Steelpillow (Talk) 22:20, 6 January 2015 (UTC)


 * I am not sure if this is a preprint, or just a draft submitted by the author last year - the final, corrected draft is not due until the Summer and there appears no definitive publication date. Meanwhile continues to add new material based on this MS, including various neologisms such as adding "ditel" here. He says above that he "takes responsibility" for this, but that is meaningless because he can wait another fifteen years for it to appear if he wants to. Who is to call that "responsibility" in? Is this situation really acceptable? &mdash; Cheers, Steelpillow (Talk) 11:32, 13 January 2015 (UTC)


 * In that case, I answered your fact challenge with an explicit reference (Regular polytopes, p. 129) And in adding ditel, I referenced a published paper by Professor Johnson. I'm not interested in bias or special treatment for Johnson's terms over any other possibilities. I'm simply giving readers an alternative term besides 1-polytope. If dyad or ditelon or any other terminology exists in usage, and reference can be made, I'd support including those as well. Tom Ruen (talk) 20:41, 13 January 2015 (UTC)
 * Your reference for "ditel" appears to be an unrefereed conference paper of dubious reliability. In any case, copying a term that is used in a single publication, and writing the article in such a way as to imply that this term is in general usage, was a mistake. —David Eppstein (talk) 21:39, 13 January 2015 (UTC)
 * BTW, Here's an example of the type of referencing I consider problematic. This edit adds three non-inline sources to the references section of an (already adequately-referenced) article; the one I can most easily check (Grünbaum and Shephard's book Tilings and Patterns) is a book reference without page numbers (see a recent discussion on this type of problem at Wikipedia talk:Scientific citation guidelines) but I have the whole book and while it does have a few pages on star polygons they do not include any mention of the specific subject of the article; I am very skeptical that the other two references contain nontrivial content about the subject either. Basically, it seems to miss the point of adding references: to make it possible to verify that the claims within the article are true and known. These references neither support any claims, nor provide any additional information about the subject of the article; they appear to be there only as a form of decoration, to make it look like the article has references. I reverted the edit for this reason but many similar sets of bad references exist in our other polygon/polyhedron/polytope articles. —David Eppstein (talk) 19:23, 23 January 2015 (UTC)

Draft reviews
Hey all - I posted these here last month, but was hoping if I could get more eyes on these drafts that have potential: Thank you! ~ Super  Hamster  Talk Contribs 06:10, 24 January 2015 (UTC)
 * Draft:Matrix regularization
 * Draft:Loss function surrogates for classification

A discussion of what to do with the redirect and the name of the article summation is occurring at talk:summation -- 65.94.40.137 (talk) 11:00, 26 January 2015 (UTC)


 * An editor has asked for a discussion to address the redirect Sum. Please participate in the redirect discussion if you have not already done so. 65.94.40.137 (talk) 11:26, 26 January 2015 (UTC)

Ihor Voloshyn (talk) 13:46, 26 January 2015 (UTC)

Compact finite difference
Compact finite difference is a new article that could use some cleanup, if indeed it ought to exist. Michael Hardy (talk) 03:45, 29 January 2015 (UTC)

Star polygons being saturated with images
Hi, I could use some help at Star polygon. added a big block of images that I felt breached WP:GALLERY and WP:NOTGALLERY. I removed it and he began warring over it. After I opened a discussion on the talk page at Talk:Star polygon, he continued adding more. I have posted a more detailed history of the warring there. Could some more eyes come and determine whether I am just being a grumpy old git or is Tom debasing our encyclopedia? &mdash; Cheers, Steelpillow (Talk) 10:54, 31 January 2015 (UTC)


 * The conflict was in the section Star_polygon, and a compromise seems to have been reached. Tom Ruen (talk) 12:37, 31 January 2015 (UTC)


 * On the contrary, a third editor cut the gallery down drastically and Tom has since added images back in again without discussion. I am close to taking this to WP:ANI. &mdash; Cheers, Steelpillow (Talk) 13:10, 31 January 2015 (UTC)


 * Total lies of a confused mind. This is false. Tom Ruen (talk) 13:35, 31 January 2015 (UTC)


 * That goes straight to ANI at Tom Ruen warring with gross incivility. &mdash; Cheers, Steelpillow (Talk) 14:21, 31 January 2015 (UTC)