Wikipedia talk:WikiProject Mathematics/Archive/2012/May

Kernel (mathematics)

Kernel (mathematics) has been tagged as a disambiguation page, but it runs afoul of WP:INCOMPDAB and in accordance with that policy is likely to be merged/redirected into Kernel (disambiguation)#Mathematics; furthermore, in accordance with WP:MOSDAB, most of the information will be stripped, except for one blue link per line and the minimum amount of information needed to direct a searcher to the most appropriate article for a given meaning. Since the page has 60 incoming links, it is likely that dozens of disambiguators will be drawn to this page, and will edit it to implement those guidelines, either by drastically culling its content, or by redirecting it to the existing section at Kernel (disambiguation). However, it would be a shame to lose all the work that has been put into this page, so perhaps some other formulation can be arrived at where it is not tagged as a disambiguation page. Cheers! bd2412 T 15:25, 2 May 2012 (UTC)

IMO, there is the matter here for two concept pages. Firstly, kernel of a mapping for a subset that measures how far the mapping is from being injective or being an homomorphism. Secondly, kernel of a functional transformation, for a (functional) parameter of some class of functional transformations or mappings. I have edited in this way the general definitions in Kernel (mathematics). As the first usage seems much more frequent than the second one, I propose to split this article into two articles which could be named Kernel (mathematics) and Kernel (functional mapping), with a hatnote in the first one. D.Lazard (talk) 17:24, 2 May 2012 (UTC)

I don't understand why User:BD2412 makes such dire predictions. WP:INCOMPDAB is a guideline, not policy, and the top of that page states that occasional exceptions may apply. Kernel (mathematics) is one of those exceptions. It's been reasonably stable for some years now. There's nothing on the talk page that suggests people are dissatisfied with it, and I don't see a merge proposal listed anywhere. What reason is there to believe it should change in the near future? Jowa fan (talk) 23:28, 2 May 2012 (UTC)

It is likely to change because this page is now near the top of the monthly report for Wikipedia:Disambiguation pages with links. Those are the pages that draw the most attention from disambiguators. Of course, the page will go off of that list if the incoming links are fixed so that they point somewhere else. bd2412 T 14:43, 3 May 2012 (UTC)

Two-way ANOVA

Two-way analysis of variance is an article that needs a lot of work. Probably more than one person can do in one day. Michael Hardy (talk) 16:49, 3 May 2012 (UTC)

MathJax

Is anyone else having problems viewing maths text? All <math>...</math> strings are being displayed as $...$ with the LaTeX code being shown explicitly. — Fly by Night (talk) 20:11, 2 April 2012 (UTC)

Sorry, my bad. See User_talk:Nageh/mathJax#Troubleshooting. Nageh (talk) 20:44, 2 April 2012 (UTC)

On a related note, when is Wikipedia finally going to switch to MathJax? It has been working for me flawlessly for quite some time now (except all the text art in italic and bold with html super/subscripts instead of math looks bad in comparison - as it should), but when I arrive to a Wikipedia link without being logged in, I still see the legacy math rendering as images. Jmath666 (talk) 01:21, 7 April 2012 (UTC)

The last update I saw on this was on Wikipedia_talk:WikiProject_Mathematics/Archive/2012/Mar#MathJax_update. See also the list of dependencies of bug 31406. Helder 20:17, 9 April 2012 (UTC)

Some progress on this its now live on mediawiki.org.--Salix (talk): 06:35, 18 April 2012 (UTC)

It's a pity that my changes are repeatedly being ignored without feedback. That implementation is pretty broken. Nageh (talk) 10:28, 18 April 2012 (UTC)

Are you going through the bug tracking system. I find dev tend to look at that rather than the wiki pages. Quite a few MathJax bugs don't seem to me linked to the master MathJax bug bug 31406. So they might be missed. I've added a couple to the block list.--Salix (talk): 10:48, 18 April 2012 (UTC)

Well, ok, I have created an account, and commented on a couple of these bugs. Nageh (talk) 12:17, 18 April 2012 (UTC)

Per bugzilla:31406#c24, the experimental MathJax option is now available on your preferences. In case anyone find some other bug which was not reported yet (see this list), please report it directly on bugzilla. Helder 16:45, 3 May 2012 (UTC)

Tracked in Phabricator
Task T38059

Helder, maybe you can answer me since the developers have apparently decided to ignore me. Why is the MathJax option being rolled out but bugs introduced in MediaWiki pointed out by me weeks ago are not being fixed? There is little point in testing a broken implementation of MathJax. Nageh (talk) 16:53, 3 May 2012 (UTC)

Do you have a test case of a broken page?--Salix (talk): 16:58, 3 May 2012 (UTC)

I have detailed the problem here. Nageh (talk) 16:59, 3 May 2012 (UTC)

Ah Help:Displaying a formula#Differential equation <math>u'' + p(x)u' + q(x)u=f(x),\quad x>a</math> is broken giving $u''+p(x)u'+q(x)u=f(x),\quad x>a$. I've added that as a testcase in 36059 and set that as blocking 31406.--Salix (talk): 17:18, 3 May 2012 (UTC)

All maths that contains <, >, or & is broken. Nageh (talk) 20:40, 3 May 2012 (UTC)

I'm don't know. Maybe it was because the prority/severity fields were set to "Normal". I changed the fields today and added links to this section, to de:Portal Diskussion:Mathematik#Mathjax wird getestet! and to the village pump. Other possibility is that the bug was added as a dependency to T33406 too late (only after Erik Möller said it was "ready to be enabled site-wide as an opt-in preference", and less than two hours before the setting was actually changed by Reedy). Helder 09:35, 4 May 2012 (UTC)

FAQ

I added the following to the FAQ at the top of this page following what seemed to be a favorable discussion last month: "Why don't math pages rely more on helpful YouTube videos and media coverage of mathematical issues? A.: Mathematical content of YouTube videos is often unreliable. Media reports are typically sensationalistic. This is why they are generally avoided." This was promptly deleted by a tauist. It would be useful to put on the record a WPM opposition to such dubious sources. Tkuvho (talk) 11:51, 3 May 2012 (UTC)

Well though I personally have no objection against the explanation as stated, it may be considered somewhat misleading. First of all youtube as such is just distribution channel, which carries anything from total garbage to rather high quality. There indeed many university lectures available on youtube as well as educational films from reliable authors and it might be fair to say that they are currently underutilized in math articles. In doubt video material (on youtube or elsewhere) should just be treated like other material we recommend for further reading or alternative presentations (books, articles, websites, applets & demonstrations). Add them if they reasonably can be considered useful to readers of a particular wp article and don't add them otherwise.--Kmhkmh (talk) 12:11, 3 May 2012 (UTC)

Removing the FAQ seemed a bit peremptory, as a FAQ is not a guideline, the latter having received some discussion; also the proposal for the FAQ stood without being challenged until it was deleted. I feel that WP:YOUTUBE is not stated strongly enough for the subject area of mathematics, and could be enhanced. WP:ELNO is a bit diffuse and open to interpretation. Some YouTube links may be suitable for pedagogical purposes (a see also?) rather than for reference, and that distinction perhaps needs to be made somewhere in WP:EL. We do experience occasionally insistent additions of YouTube links, but the question to ask is: since it comes down to experienced editors removing unsuitable links in the end, what would be the best guideline/FAQ to have in place to refer persistent editors to in the case of maths articles? — Quondum^☏ 12:52, 3 May 2012 (UTC)

Changing WP:YOUTUBE guidelines may not be easy. At the very least we should be clear on this at our own FAQ. Tkuvho (talk) 13:27, 3 May 2012 (UTC)

Ok you lost em completely. Did I miss something here? Who is suggesting to delete the FAQ? As i understood it the question was about Tkuvho's text addition.--Kmhkmh (talk) 12:58, 3 May 2012 (UTC)

That reversion was by Waldir (talk · contribs) back on 10 April 2012‎. In his edit summary, he said "There was no consensus for this change.". This is not an adequate reason to revert, so I would like to hear Waldir's explanation. Perhaps we can agree on a modified version of the change.

To Tkuvho: By the way, what do you mean by "tauist"? JRSpriggs (talk) 12:57, 3 May 2012 (UTC)

The most "serious" piece to date on the subject of tau is by one Abbott, entitled: "how I converted to tauism" or something like that. Tkuvho (talk) 13:25, 3 May 2012 (UTC)

The background for this dispute concerns the recent controversy over the article Talk:Tau (2π). In my opinion, Waldir and others were attempting to use mainstream media to establish the notability of the concept, and then attempting to use those same sources to write an article that purported to be about a serious mathematical phenomenon. It seems clear to me that if this kind of bait-and-switch can be construed as permitted under our policies, then someone needs to take a hard look at those policies and see where they need to be clarified. Sławomir Biały (talk) 13:18, 3 May 2012 (UTC)

I think i misread your meaning of "relying". So to be clear, in my posting above I was talking about video material being underutilized in external links and not about its use as sources.--Kmhkmh (talk) 14:09, 3 May 2012 (UTC)

That's a valid point. Would you care to suggest an alternative wording that would make this clear? Tkuvho (talk) 14:44, 3 May 2012 (UTC)

Quoting myself above: "... suitable for pedagogical purposes (a see also?) rather than for reference, and that distinction perhaps needs to be made somewhere" – perhaps similar wording clarifying the pedagogical–reference distinction for what purpose a link is serving should be used. — Quondum^☏ 15:16, 3 May 2012 (UTC)

How about this: "Q. Why don't math pages rely more on helpful YouTube videos and media coverage of mathematical issues? A.: Mathematical content of YouTube videos is often unreliable, though some may be useful for pedagogical purposes rather than references. Media reports are typically sensationalistic. This is why they are generally avoided." Tkuvho (talk) 16:50, 3 May 2012 (UTC)

Fine by me. If it's impractical to modify the guidelines to reflect the particular caution relating to the more stringent requirements for mathematics references, then a FAQ can fill the role. If people have objections to the wording, it can be fine-tuned. — Quondum^☏ 09:55, 4 May 2012 (UTC)

It seems that comments in this discussion still ignore the point that some YouTube videos are indeed reliable. As Kmhkmh said, YouTube is primarily a distribution channel, and we should probably do better than say "all content on YouTube is unreliable". For example, there was a minor claim at Raptor code, which I knew was true but was tagged with {{dubious}}, and the only (but reliable) source I could find on this was a talk given by the primary inventor at a university, which recorded his talk and put it on YouTube. But maybe this is just an exception to the rule, not worthy of further mention? Nageh (talk) 11:35, 4 May 2012 (UTC)

Though I agree that there are videos tat can be considered (somewhat) reliable (tutorials from reliable authors/publishers, academic lectures, conferences or talks by reputable scholars,...) they are still a poor choice for sourcing content, as all math statement being mentioned in those can usually be found in proper written publications as well, which would be the preferred choice. You probably can argue better sourcing some claim with a video lecture (where it is mentioned) than with no source at all, but the problem starts with claims who are not known to (obviously) true or even disputed in such cases having a statement in lecture as the only source is not good enough. Also in such harmless undisputed cases lecture notes/sripts might probably better as a "emergency source" than a video of a talk or lecture.--Kmhkmh (talk) 12:04, 4 May 2012 (UTC)

So while it might be permissible in your case or some other rare cases it is not a sourcing practice we should encourage. Note the discussion was about "using videos/youtube more often" rather than "explicitly forbidding any use" and your scenario is more dealing with the latter rather than the former. However outside of sourcing issues, we nevertheless could use videos more often for pedagogic/further information reasons under external links.--Kmhkmh (talk) 12:04, 4 May 2012 (UTC)

Yeah, I agree. And definitely, such sources should not be encouraged. Nageh (talk) 12:09, 4 May 2012 (UTC)

A dubious new category

Today, Wackywill1001 (talk · contribs) created Category:E (mathematical constant) as a subcategory of Category:Mathematical constants. Yet it contains articles which are not about mathematical constants and only incidentally about e. JRSpriggs (talk) 15:02, 4 May 2012 (UTC)

xdvi

I've created a new article titled xdvi. It's still quite stubby. Have fun improving and extending it. Michael Hardy (talk) 16:54, 4 May 2012 (UTC)

Evaluating sums -- hopeless?

I was looking at the article Evaluating sums to see if I could improve it, but I think I've decided that it's hopeless: the title subject is so over-broad that there's no possible way to give a comprehensive encyclopedic treatment, while the article as written might be better titled methods of computing certain numerical series known to bright high school students. And, of course, all of the content is included in articles like arithmetic progression and Taylor series, where it has appropriate context. I don't care enough about this to learn how to go about proposing articles for deletion, but perhaps someone who agrees might go about it. --Joel B. Lewis (talk) 23:17, 7 May 2012 (UTC)

I went over the article in an attempt to save it, but the patient flatlined. CRGreathouse (t | c) 15:20, 8 May 2012 (UTC)

Article as code repository?

The section Computer program of the article Look-and-say sequence consists of code in Python and Javascript to generate the sequence that is the subject of the article. Is it usual practice to have such code in Wikipedia articles? (By the way, if anyone had any reliable sources for the section on "pea pattern", that would be wonderful.) --Joel B. Lewis (talk) 00:08, 8 May 2012 (UTC)

This comes up periodically; I think some past discussions can probably be found in the archives of Wikipedia talk:WikiProject Computer Science. My own feeling is that (1) code or pseudocode is an appropriate way of describing algorithms, when that algorithm is relevant for the content of the article; (2) pseudocode is generally preferable to code, but code may be clearer in some cases when using language-specific features that are difficult to describe in pseudocode such as the yield keyword and regular expressions of the example you link to; (3) because the purpose of including code is to explain algorithms to people rather than to provide a code repository for programmers to copy from, we should never have multiple redundant implementations of the same algorithm in different languages; if multiple implementations are included (as they are in this case) it should only be to describe algorithms that are significantly different from each other (as they are in this case); (4) we shouldn't require the exact same source code to be present in a reliable source (that would likely be a copyvio) but it is reasonable to require the algorithm itself to be sourced. Despite having contributed to the Python version for this article I don't have a strong opinion on whether the algorithms described in this case are relevant enough to the main topic or free enough of original research to be included. —David Eppstein (talk) 00:31, 8 May 2012 (UTC)

Since this is something that keeps coming up from time to time, would it make sense to have better integration with something like Wikisource, where detailed implementations can be included? Or is this just inviting other problems? Sławomir Biały (talk) 13:23, 8 May 2012 (UTC)

There is also http://rosettacode.org. Helder 13:26, 8 May 2012 (UTC)

List of things named after Charles Hermite

We have a new List of things named after Charles Hermite. Work on it! Michael Hardy (talk) 04:08, 9 May 2012 (UTC)

You might want a link to it from the article on Charles Hermite. JRSpriggs (talk) 06:03, 9 May 2012 (UTC)

Polyhedra

Hi all,

Double sharp and I were discussing earlier about the coverage of uniform and pseudo-uniform polyhedra on Wikipedia. In fact, we've just started work on a few articles. (The main discussion is on my talk page, though I am not really that active in it.) Please help out!

Thanks,

Your old friend, "The Doctahedron" 68.173.113.106 (talk) 21:27, 8 May 2012 (UTC)

I've created pseudo-uniform polyhedron. It's still incomplete, with only one section filled in. Double sharp (talk) 10:04, 9 May 2012 (UTC)

Paper written by a particular person?

Is the Bachmann who wrote this paper Paul Gustav Heinrich Bachmann? My guess is yes, but I am not sure how to confirm it. The paper does not give his full name. I need to know this, because I want to wikilink him in an article. -- Toshio Yamaguchi (tlk−ctb) 06:34, 10 May 2012 (UTC)

Searching for the author Bachmann at Zentralblatt seems to confirm it. The topic of P. Bachmann at the time period is number theory and Fermat's theorems, and in some entries the name is expanded to "Bachmann, Paul [-1920]". For instance, here. So I'd say, in this period there is only one P. Bachmann publishing in mathematical journals, P. is Paul, and the data and topics coincide with the biography above.--LutzL (talk) 08:28, 10 May 2012 (UTC)

I wikilinked the name to Paul Gustav Heinrich Bachmann. Thanks. -- Toshio Yamaguchi (tlk−ctb) 11:43, 10 May 2012 (UTC)

The ultimate problem of this kind is probably that of Charles Paul Narcisse Moreau. It is suspected, and reasonably probable, that three people named Moreau are really all the same person, and some people have made considerable efforts to confirm or refute that hypothesis without success. Michael Hardy (talk) 16:25, 11 May 2012 (UTC)

Eilenberg-Ganea theorem

I'm good at math but not this good. The article Wikipedia talk:Articles for creation/Eilenberg-Ganea theorem was not moved to article space because of concerns with inline citations. While I agree that the concerns exist, the article appears to be ready for the article space as long as {{More footnotes}} is added. Can someone who might actually know what they are talking about take a look at it to see if it is able to be moved? Ryan Vesey Review me! 20:12, 11 May 2012 (UTC)

Some aspects of the article pretty thoroughly violated WP:MOSMATH, and to a lesser extent WP:MOS, but I've fixed those. (Apparently someone thought everything in non-TeX math notation should be indiscriminately italicized, including even parentheses and digits, etc., and wrote \text{sup} instead of \sup, and various other things like that. In fact, some things on the same line where "\text{sup}" appeared didn't use \text where \text was appropriate and artificially added spacing between words.) There was also a mathematical thing that didn't make sense: "$\sup _{k}\{[{\text{condition involving }}k]({\text{ true or false depending on }}k)\}$" appeared. Where $\sup _{k}$ appears, I expect "$\sup _{k}({\text{something whose value depends on }}k)$". Finally I thought what was probably meant was "$\sup\{k:[{\text{condition involving }}k]({\text{ true or false depending on }}k)\}$" was probably meant, and I changed it to that. Michael Hardy (talk) 23:02, 11 May 2012 (UTC)

The author is a relatively new user. It might be good to leave him/her a note describing WP:MOSMATH. Do you believe the page could be moved to article space? Ryan Vesey Review me! 23:06, 11 May 2012 (UTC)

File:Formal languages.png

Is it appropriate in Portal:Logic/Selected article/3? It certainly is not appropriate in any of the articles to which Greg has added it over time. — Arthur Rubin (talk) 15:21, 13 May 2012 (UTC)

This is a formal written request for members of WP:MATH to cease and desist from further removal of the File:Formal languages.png from articles in which it appears until such time as productive criticism which may lead to its amendment arises. Please be advised that "i don't like it" and any other formulations thereof DO NOT qualify as productive. Heretofore, the only criticism I have seen which shed any light at all is that it is "simple." So what more complex concepts are needed. I say none. It is meant to be a simple diagram custom made for the articles in which it appears. I took the time and effort to make it. Show some respect for their efforts of others. Greg Bard (talk) 21:36, 13 May 2012 (UTC)

Formal request has no meaning in this context. If you want to argue over images the most relevant consideration is WP:PERTINENCE. Please sign your talk page 'missives' with ~~~~. See WP:TPO about moving the comments around. Dmcq (talk) 21:19, 13 May 2012 (UTC)

Take it for what it is worth. If I continue to have problems, I will take it to ANI, if this isn't the place for formalities. Greg Bard (talk) 21:36, 13 May 2012 (UTC)

Please do so as you seem unable to treat people here with consideration and respect as per WP:CIVILITY. Dmcq (talk) 21:48, 13 May 2012 (UTC)

Absolutely outrageous. Someone takes it upon themselves to consistently go through deleting all instances of an image created by a user for a specific and useful purpose (on what grounds we haven't been told) and when he protests about it, all you can do is complain about the fact that he rearranges stuff around on a talk page? Shame on you.

For what it's worth I can't see any reason for deleting that File:Formal languages.png link. While there may be "civility" issues over the talk page, which appears to be objected to on pharisaical grounds, the consistent deletion of this file is a more important issue and needs to be addressed. In my view, it's a good icon as it encapsulates the whole field of formal languages in one easy little picture. --Matt Westwood 22:15, 13 May 2012 (UTC)

Thank you for your attention to this issue, and thank you for observing that while all I want to do is move forward, certain people here would rather do nothing but make problems. I still haven't seen a single contribution that would consist in something that a productive editor could use to improve the image to their satisfaction. That should tell you everything you need to know about this issue, and the maturity of certain editors. Please do monitor this issue. You could serve as a reasonable mediator, as I prefer not to deal with this community (WP:MATH), in general.Greg Bard (talk) 23:49, 13 May 2012 (UTC)

Nice idea, but I lack the patience and commitment - the main bulk of my energies lie elsewhere as the deletionists have sourced me on WP. --Matt Westwood 05:06, 14 May 2012 (UTC)

This image has been discussed on this page twice before: [1] and [2]. It has probably also been discussed on various of the respective talk pages of the affected articles; it's difficult to gauge. Sławomir Biały (talk) 23:23, 13 May 2012 (UTC)

The image is not totally correct in that not all theorems are well formed formulae, at best formal theorems are. I'm happy however for it or something like it to be in articles in circumstances where the 'formal' is explicit or implied like the formal theorem section of theorem. The problem I had with it before was that it kept on being made larger and larger and the text below it longer and longer. Illustrations are supposed to illustrate the text. We should not be putting in mini essays under illustrations. As to the behaviour above being absolutely outrageous, civility is a policy and listed in WP:5P, but WP:PERTINENCE is part of the guideline WP:IMAGES. Policy is more important than guidelines and civility is more important than illustrations. Dmcq (talk) 23:43, 13 May 2012 (UTC)

Okay, so the illo needs improvement. I still believe that before deleting it out of hand, an attempt is made to amend it (or at least to flag that need up) rather than just delete something because it's not liked, for whatever reason. --Matt Westwood 05:06, 14 May 2012 (UTC)

Please also see the bit in WP:5P about 'Since all your contributions are freely licensed to the public, no editor owns any article; all of your contributions can and will be mercilessly edited and redistributed.' and compare to the bit about formal warning above about removing the contributors image. Dmcq (talk) 23:52, 13 May 2012 (UTC)

Ultimately yes, but have a heart. Deletionists have ruined WP for me and many others. --Matt Westwood 05:06, 14 May 2012 (UTC)

I have never seen a reason for inclusion of the image. It's marginally acceptable, although misleading, in theorem and WFF, but has no place in symbol (formal). It's certainly not central enough in Portal:Logic to belong there. — Arthur Rubin (talk) 07:16, 14 May 2012 (UTC)

Well just having had a quick look at the other entries in Portal:Logic/Selected_article I can't say I think any of them are exactly wonderful. However it really is up to people interested in that area to stick better stuff into the portal and I'd only start removing things which were actually badly wrong at the moment. One thing I will say is that the size of the image is about right there I think rather than having the super heavyweight text size used in the articles. I had a look too at the article symbol (formal) and I'm rather confused by it. There is a bit there saying that for instance logical constants are not formal symbols. However the diagram just refers to symbols and strings. I think perhaps there is the same problem there as was in the article theorem where at one stage theorems and the idea of formal theorems as strings following some rules were mixed up together and not properly distinguished. Dmcq (talk) 08:29, 14 May 2012 (UTC)

No. At no point does the article state or imply that a logical constant is not a formal symbol. It says that it is not a symbol of anything. That is to say that a logical constant is an abstract idea. It does not appear to the mind as a particular image. Therefore it is not a symbol of anything in particular.Greg Bard (talk) 08:42, 14 May 2012 (UTC) HEY! You'll have to forgive me. There was a just such a false statement that was added by someone that I was unaware of. I have removed it. It was a valid observation of your part. Greg Bard (talk) 08:51, 14 May 2012 (UTC) Also, Dmcq, I see in an earlier paragraph that you express some concerns with the image which may be addressed in a well crafted caption. Greg Bard (talk) 09:20, 14 May 2012 (UTC)

Magdy's Exchanger at Afd

Please see Wikipedia:Articles for deletion/Magdy's Exchanger. Magdy's Exchanger appears to be original research by Ahmed Magdy Hosny (talk · contribs). JRSpriggs (talk) 23:43, 13 May 2012 (UTC)

Electrodynamic tether

I noticed the reason for the Wikify tag on the article Electrodynamic tether. I have no idea how to do that, and I don't know if other editors at Wikipedia:WikiProject Wikify do either. Can someone here try to make those improvements? Ryan Vesey Review me! 02:52, 16 May 2012 (UTC)

Gosh, that article is something of a monster. The images-as-figures issue is now resolved; I don't do wikitables, but resolving them shouldn't be hard for someone who knows the syntax. Joel B. Lewis (talk) 17:00, 16 May 2012 (UTC)

I think you might do better to ask at Wikipedia talk:WikiProject Physics or Wikipedia talk:WikiProject Engineering. JRSpriggs (talk) 17:16, 16 May 2012 (UTC)

Formatting question

Easy question to answer I'm sure, I just can't seem to find the answer. We prefer to write "[[homomorphic image]]s" to "[[homomorphic image|homomorphic images]]", right? I mean that we prefer to put the s outside the linking rather than require using the pipe. Rschwieb (talk) 12:13, 16 May 2012 (UTC)

The WP Manual of style WP:LINK says that either is okay, but most editors put the "s" outside the brackets:

Plurals and other derived names. When forming plurals, you can do so thus: [[apple]]s which includes the final "s" in the link like this: apples. This is easier to type and clearer to read in the source text than [[apple|apples]]. This works not just for "s", but for any words that consist of an article name and some additional letters. For details, see Help:Link. (This does not work for affixes beginning with hyphens, apostrophes, or capital letters.)

In theory, both approaches will look identical to the reader (the "s" will be blue in both situations). --Noleander (talk) 12:58, 16 May 2012 (UTC)

From WP:LINK#Piped_links

Piping and redirects. Per § Link specificity above, do not use a piped link where it is possible to use a redirected term that fits well within the scope of the text. For example, let's assume the page A Dirge for Sabis is a redirect to the page The Sword of Knowledge, and while you're editing some other article, you want to add a link to A Dirge for Sabis. You may be tempted to avoid the redirect by directly linking to it with a pipe like this: [[The Sword of Knowledge|A Dirge for Sabis]]. Instead, write simply [[A Dirge for Sabis]] and let the system handle the rest. This has the added advantage that if an article is written later about the more specific subject (in this case, A Dirge for Sabis), fewer links will need to be changed to accommodate for the new article.

I think this suggests a general principle of transparency being preferred (avoiding piped links when an unpiped link will do). — Quondum^☏ 13:16, 16 May 2012 (UTC)

Since we have some bots which will remove the pipe in this case, I would say yes to avoid an extra edit. But do not edit the source merely to change that one thing. Only change it incidentally when the opportunity arises while editing something else in that section. JRSpriggs (talk) 16:49, 16 May 2012 (UTC)

Thanks for the advice, all. Rschwieb (talk) 21:14, 17 May 2012 (UTC)

Weisstein and Wolfram as source ?

My recent edit in absolute value has been reverted and the summary of the reversion links to Wolfram research and Weisstein as source. I agree that sourcing to Weisstein is frequently easy. But it is a commercial ressource, which is not peer reviewed. Is it correct to use it as authoritative source? D.Lazard (talk) 11:35, 9 May 2012 (UTC)

First of all we need to distinguish between MathWorld (Weisstein) and WolframAlpha. And secondly we need to distinguish between actual sourcing and using some external site as a discussion/plausibility argument. Personally I'd consider the comment in the version history as the latter rather than the former.

Whether a source is commcercial or not doesn't really matter imho. Strictly speaking are many/most scholarly publication commcercial since they are published through commercial publishing companies. Peer reviewed publications are certainly preferred, but in many cases we resort to other reliable (scholarly) publications which have nor undergone a peer review in the sense of a peer review process (for instance many textbooks).

MathWorld is certainly a "mediocre" source in some regard, however formally it qualifies as a reliable source and in many situations it is perfectly to be used as a source (however it might always be replaced by a better source of course as peer reviewed journal publication or some well received textbook).

WolframAlpha might be more controversial, in theory it could be treated like some tertiary source (say an encyclopedia or some scientific database). However since its content is partially program generated that might be a questionable call still.--Kmhkmh (talk) 13:24, 9 May 2012 (UTC)

It's perhaps worth noting that in this case, the changes being made were totally inane: things like replacing x/|x| with |x|/x and a*sign(a) with a/sign(a). (Actually the latter was not just inane but also wrong.) On general principle: the idea that the order of the symbols on Wikipedia should be required to match the order produced by any Wolfram product is absurd; the "reference" to WolframAlpha is particularly absurd, because who knows if it will remain stable in the order that it writes its output? (I'm also skeptical that it counts as a reliable source.) --Joel B. Lewis (talk) 13:55, 9 May 2012 (UTC)

Well you can certainly argue that there was some oversourcing as in sourcing well known domain knowledge and/or sourcing any any sentence or sign. The actual content dispute in this case didn't make much sense either and we certainly don't need WolframAlhpa to tell us how to write formulas.--Kmhkmh (talk) 15:08, 9 May 2012 (UTC)

The last section was referenced entirely to Wolfram Alpha. I have removed this section. The penultimate section had no references at all, and was unreferenced for a very long time. That section prominently bore a citation needed tag until it was inappropriately removed by some editor, who then proceded to fill it up with more original research. I have removed that section as well. The same editor added things like:

$\int |f(x)|\,dx=\operatorname {sgn} f(x)\int f(x)\,dx$

to the article (also now removed). This article needs to be watched by more people who actually know something, since there is clearly a WP:RANDY at work. Also, I'm sure a glance at the discussion page is enough to convince a mathematician that the Dunning-Kruger effect is in full swing there. Sławomir Biały (talk) 14:16, 9 May 2012 (UTC)

I certainly don't think that W|A is a WP:RS. At best it qualifies as a tertiary source, but I've seen enough unambiguously wrong material from it that I wouldn't trust it even as that. (I used to send in error reports, but I've stopped.) I'm fine with MathWorld (though additional sourcing is best, as usual). CRGreathouse (t | c) 17:02, 11 May 2012 (UTC)

Additional eyes at absolute value are needed. There is an editor keen on adding several sections of original research, including the one sourced entirely to Wolfram Alpha. Sławomir Biały (talk) 21:09, 18 May 2012 (UTC)

---

KlappCK (talk · contribs) insists that some of his edits were valid. I am convinced that the sense of an article has higher priority than formatting, and (basic correctness of) formatting has a priority over tweaks such as replacement of \frac with \tfrac. If one apparently degrade the sense of an article, other users should not hesitate to summarily remove all tweaks to restore the correct sense. I do not object against KlappCK's formatting tweaks, although a user who easily disrupts a complicated content and starts edit wars over an OR section cannot enjoy my personal trust. Incnis Mrsi (talk) 07:40, 19 May 2012 (UTC)

Affine Grassmannian

Could someone please check the validity of this edit? — Fly by Night (talk) 23:22, 19 May 2012 (UTC)

I have corrected this mistake, but the article has multiple issues: the Grassmannian is a smooth algebraic variety defined over any field. Therefore it is a manifold if the basis field is the real or the complex one. It is defined independently of any Euclidean structure and any inner product; nevertheless they are introduced without any explanation in the definition. And so on. D.Lazard (talk) 03:03, 20 May 2012 (UTC)

Unless I've made an arithmetic mistake or the articles on the Euclidean group and the orthogonal group lie about their dimensions (but they look fine to me), the original edit is correct. Just take the dimension of E(n) minus those of E(k) and O(n − k). I.e. I think D.Lazard's correction is wrong (the n² terms will cancel). RobHar (talk) 03:07, 20 May 2012 (UTC)

I agree and I have corrected my edit. It remains that it is crazy to use Euclidean metrics and orthogonal group, that have nothing to do in this purely affine question. D.Lazard (talk) 07:11, 20 May 2012 (UTC)

While it's true that we should have a definition of the affine Grassmannian as a scheme, the definition as it currently appears is more accessible, rather than describing it as a certain scheme representing some moduli problem. Also, to be fair, the article is actually called "Affine Grassmannian (manifold)". Since this is a vector bundle over the Grassmannian, is it simple to write down a sheaf of O_Gr-algebras whose relative Spec is the affine Grassmannian? RobHar (talk) 13:52, 20 May 2012 (UTC)

IMO the best definition for this article is that which is implicit in the second section: quotient of the set of the sequences of n−k independent affine forms by the action of the the linear group of rank n−k. This may be written in an elementary way. Then the proof that it is a manifold (in case of a real or complex basis field), a smooth abstract algebraic variety, a scheme, a sheaf, ... is almost immediate as soon as one knows these notions. D.Lazard (talk) 17:56, 20 May 2012 (UTC)

I am not sure what's wrong with defining it to be the collection of affine planes. The second one introduces coordinates, one also easily shows that the resulting collection is a manifold. Expressing this in terms of k-forms may be a nice theorem, but it is hardly a definition. Tkuvho (talk) 12:33, 21 May 2012 (UTC)

Is the Kronecker delta a function, or "notational shorthand"

The Kronecker delta article seems unsure of its subject's identity. Please discuss at Talk:Kronecker delta#Clarification: is the Kronecker delta a function, or "notational shorthand"?. --TSchwenn (talk) 17:04, 21 May 2012 (UTC)

Original research classification of magic cubes

The Pantriagdiag magic cube (AfD discussion) article is currently listed for deletion. Other articles in the same vein are diagonal magic cube, pantriagonal magic cube, pandiagonal magic cube, and perfect magic cube. I observe that we seem to have a bit of a problem with magic cube classification. I refer you to the second sentence of magic cube classes, whose boldface is in the article itself:

This new system is more precise in defining magic cubes.

The new system, it turns out, is the invention of Harvey Heinz (talk · contribs), who put up his new system on two sets of WWW pages and in a self-published book (Harvey D. Heinz Publishing), and who came to Wikipedia and wrote all of these "-agonal" articles, the magic cube classes article, and also the perfect magic cube#An alternative definition section of the perfect magic cube article. Wikipedia seems to be presenting an acknowledged idiosyncratic and novel classification of this subject.

Uncle G (talk) 15:09, 22 May 2012 (UTC)

List of scientific constants named after people

The list of scientific constants named after people includes a section on mathematical constants. The mathematical and physical parts should each be a hundred times as long as it is. Work on it. Michael Hardy (talk) 22:17, 22 May 2012 (UTC)

Template:WikiProject Mathematics

I would like to resurrect Template:WikiProject Mathematics. It is no longer used. Template:Maths rating is used instead. I think it is nice to be consistent with other wikiprojects. Makes the housekeeping easier. Is there WP-wide guidelines on this sort of thing? -- Alan Liefting (talk - contribs)

There is no wiki-wide guideline. There was a recent discussion in March [3] that resulted in the current name being kept.

There aren't actually any housekeeping problems with the current name. On the other hand, unlike other projects, we do not need to tag articles just to say they are related to math; the name "maths rating" emphasizes that the purpose of the template is rating information. — Carl (CBM · talk) 01:59, 23 May 2012 (UTC)

Hmmm. This makes it a little harder for editors who work across all WikiProjects. From the discussion it looks like I am not the only one who has run into this little glitch. -- Alan Liefting (talk - contribs) 02:14, 23 May 2012 (UTC)

In general, if you don't deal much with mathematics articles and aren't comfortable assessing them, there's no reason why you need to worry about the {{maths rating}} template at all, you can just ignore it. — Carl (CBM · talk) 02:18, 23 May 2012 (UTC)

Category template deletion

Wikipedia:Templates_for_discussion/Log/2012_May_23#Template:Category-Logic.2Fheader

I wonder what you guys think about this template deletion at Category:Logic. Greg Bard (talk) 01:18, 24 May 2012 (UTC)

I see it has provoked Wikipedia:Village pump (policy)#Competition for the worst Wikipedia page - be in to win!. Personally I was just ignoring the deletion talk as I have a bit of a laissez faire attitude unless things really cause trouble and also I think that business is rather unfair about the template. Dmcq (talk) 18:17, 25 May 2012 (UTC)

Power spectrum estimation

Our coverage of power spectrum estimation (spectral density estimation) seems very weak, with very little bringing together or contrasting the different methods, or giving historical perspective. Indeed, most articles looking for a signal processing treatment of the subject appear to have been being redirected to spectrum analyzer, about a hardware box with very little discussion of algorithms usually used in pure-software methods.

In particular, there is very little discussion of all-poles versus all-zeros methods. There appears to be nothing at all about John Parker Burg or the Burg algorithm. We have quite a detailed article on the Levinson recursion, but nothing to say that this is perhaps its most important application. Linear predictive coding appears to exist in a silo of its own, without even a link to ARMA modelling; while in turn the article on ARMA models doesn't appear to mention power spectrum estimation at all. Autoregressive model is a bit better, but doesn't give any sense how a pure AR fit is likely to compare to other fits.

It probably doesn't help that spectral analysis goes to a dab page, and the top link spectrum analysis that probably ought to be merged into spectroscopy.

This is very poor. Given the importance of this topic in signal processing and applications, we ought to be able to match at minimum the level of discussion in Numerical Recipes at least. But at the moment we're way short. Anybody out there willing to step up to the plate? Jheald (talk) 09:23, 26 May 2012 (UTC)

Cross-posted to WT:WPSTATS, WT:PHYSICS Jheald (talk) 09:29, 26 May 2012 (UTC)

Discussion moved to Talk:Spectral density estimation#Coverage. --TSchwenn (talk) 17:12, 26 May 2012 (UTC)

maclaurin

The following footnote at Colin Maclaurin is sourced at a personal page at the university of rochester:

"Neither Newton nor Leibniz – The Pre-History of Calculus and Celestial Mechanics in Medieval Kerala". MAT 314. Canisius College. Retrieved 2006-07-09."

I wonder if it is the optimal source for the information. Tkuvho (talk) 08:20, 29 May 2012 (UTC)

It is a powerpoint and a book or article would be better. But to be frank I was pleasantly surprised by its quality. It might be I've come across too many people pushing the evidence way past where it should go when bigging up their countries contributions.. Dmcq (talk) 09:00, 29 May 2012 (UTC)

In any case, it is not clear which assertion is sourced from this course. In fact I can not understand the paragraph referring to this source, especially the sentence "At the time, Maclaurin was unaware and published his work in Methodus incrementorum directa et inversa, Maclaurin series which are Taylor series expanded around 0, and are not attributed to Maclaurin due to the past discoveries, ...". Can someone understand this? D.Lazard (talk) 09:17, 29 May 2012 (UTC)

My guess would be that the footnote is only used for the assertion that some form of Maclaurin series was known to the Kerala school. There is another reference for this assertion in Taylor series which points to an article by Dani; that might be a better one but I cannot access it. Regarding the sentence D.Lazard quotes, Methodus incrementorum directa et inversa was written by Taylor, so something has gone wrong there. I rewrote the paragraph using the article by Gradiner referred to, so hopefully it makes more sense now. -- Jitse Niesen (talk) 11:25, 29 May 2012 (UTC)

The Canisius College link is broken 2013-05-01

Content fork in Finitely generated projective module

The page Finitely generated projective module has been created recently. IMO, this is a redundant content fork and this page has to be merged into Projective module. I have started a discussion in Talk:Finitely generated projective module and the author of the article disagrees. Please comment there. D.Lazard (talk) 13:04, 27 May 2012 (UTC) — (Links corrected after reading next post. D.Lazard (talk) 14:13, 27 May 2012 (UTC) )

I think you mean Finitely generated projective module. --Zundark (talk) 13:52, 27 May 2012 (UTC)

OOPS. You are right. Such a long title is, may be, another reason to merge. D.Lazard (talk) 14:13, 27 May 2012 (UTC)

Actually the precise term would be "finitely generated projective module over a commutative ring possibly without unity" (sorry, couldn't resist) The exclusion of unity is useful in allowing a commutative Banach algebra, as I understand. I think the subject suffers from a lack of catchy name. -- Taku (talk) 15:54, 30 May 2012 (UTC)