Wikipedia talk:WikiProject Mathematics/Archive/2014/Jan

Wikipedia:Articles for deletion/Gilles Baroin

The new article Gilles Baroin is up for deletion. Sławomir Biały (talk) 14:01, 1 January 2014 (UTC)

Epsilon zero

At the moment, wikipedia seems to be slightly confused about epsilon zero:

• Epsilon zero and ε₀ (Ε₀) redirect to Epsilon numbers (mathematics).
• Epsilon 0 and Epsilon naught and ε0 (Ε0) redirect to Epsilon number, a disambiguation page.
• Epsilon nought and Epsilon sub zero redirect to Vacuum permittivity.

I think that vacuum permittivity is the most common meaning of epsilon zero (but then again, I am a physicist), and there is some discussion of this issue at Talk:Epsilon numbers (mathematics)#Redirect?, from a time before ε₀ (Ε₀) was moved to epsilon numbers (mathematics). I think that Epsilon zero and ε₀ andEpsilon 0 and Epsilon naught should be changed to redirect to Vacuum permittivity. That article already starts with a head note that says "For the ordinal number ε0, see epsilon numbers (mathematics)."

This change would mean that a number of existing links would have to be corrected. We could use the existing from epsilon zero (mathematics) to epsilon numbers (mathematics) when we fix the links.

Any suggestions/opinions? —Tobias Bergemann (talk) 10:34, 1 January 2014 (UTC)

The problem is that the short (two character) names are very difficult to find in a source file so that one can fix the link. If you look at the "What links here" for Epsilon numbers (mathematics), it is clear that all of the articles which are linking to those are, in fact, trying to link to the ordinal number and not to Vacuum permittivity. JRSpriggs (talk) 09:09, 2 January 2014 (UTC)

IMO, epsilon numbers (mathematics) must be renamed epsilon ordinals. Even for mathematician this is better, as ε and ε₀ appear commonly in other mathematical contexts, and a mathematician which reads "number" does not think first as "ordinal number". For the ε₀ and all the redirects that are synonymous, I would suggest to replace each of them by two redirects on the model ε₀ (ordinal) and ε₀ (physical constant). This will completely disambiguate at search level, at the price of editing the article linking to them. D.Lazard (talk) 11:35, 2 January 2014 (UTC)

Well, I've never heard of "epsilon ordinals", so I doubt this proposal meets COMMONNAME. But it might make sense to rename to epsilon number (set theory), and in that case surely ordinal numbers would be more likely to come readily to mind.

I note in passing that someone boldly changed the article from one on epsilon-naught specifically to one on the epsilon numbers in general, a proposal that had been discussed on the talk page without reaching resolution. That did annoy me slightly, but not enough to make a stink about it at the time, because the issue is fairly close on the merits. --Trovatore (talk) 16:15, 2 January 2014 (UTC)

I agree that "epsilon ordinal" is not a common terminology. The same is true for "epsilon number". As ordinal theory is a small part of set theory, I suggest epsilon (ordinal). D.Lazard (talk) 17:34, 2 January 2014 (UTC)

Honestly, I would prefer to move it back to something specific to ε₀, as the ε_α sequence is just not something that comes up that much, at least in my experience. I do agree that the permittivity of the vacuum is probably the primary topic for that search term, so something like ε₀ (set theory) or ε₀ (mathematical logic). --Trovatore (talk) 22:21, 2 January 2014 (UTC)

Subtraction methods

In the article subtraction, I've borrowed some great images from Deutsch Wikipedia illustrating a lot of subtraction methods. However, I had trouble writing the summaries. Would anyone be interested in explaining how the Austrian method works or improving my explanation of the American method (or even changing the name "American method")?Brirush (talk) 02:15, 3 January 2014 (UTC)

There's no way to fit in Tom Lehrer's marvelous explanation of subtraction [1] in there is there? ;-) Dmcq (talk) 17:50, 5 January 2014 (UTC)

Consistency in pluralization?

The articles parabola, hyperbola and formula all show that they can be pluralized with either an 's' or an 'e'. But within the article both are used. Should the article be made consistent on one?Naraht (talk)

The articlae (couldn't resist) should probably be internally consistent. YohanN7 (talk) 15:20, 5 January 2014 (UTC)

I have standardized hyperbola and parabola. Both articles mention (appropriately) the alternate forms, but now use only the English plural in the text. --JBL (talk) 16:04, 5 January 2014 (UTC)

I think in general Latin based plurals are disappearing in mathematics, and rightly so since math is hard enough without them. The exceptions seem to be words whose plurals would be awkward following the normal rules, 'matrices' instead of 'matrixes', 'axes' instead of 'axises'. Even this confuses a lot of people and students often talk about the 'identity matricee'. --RDBury (talk) 17:42, 5 January 2014 (UTC)

... and they all may be rulers of the Queen's Navee.... --Trovatore (talk) 23:12, 7 January 2014 (UTC)

I sometimes hear students use both "vertice" and "vertexes" in the same sentence :). Incidentally, I did not change formula because currently formulae is used more on that page than formulas and so I wanted to be sure there was general agreement on the English plural before making the switch. --JBL (talk) 15:17, 7 January 2014 (UTC)

I think someone changed it from formulas to formulae recently without asking, so they shouldn't mind if you change it back.Brirush (talk) 20:49, 7 January 2014 (UTC)

Thank you for pointing that out; I've now done the same to formula as to the others. --JBL (talk) 22:40, 7 January 2014 (UTC)

Binary notation

When talking about plural digits, should we use 1s and 0s (ones or zeros), or 1's and 0's (which implies possession but seems to be more widely used)? P.S. Why do mathematicians confuse Halloween with Christmas? Because oct(31) = dec(25) --Gilderien Chat|List of good deeds 00:23, 25 December 2013 (UTC)

I'm sure that there will be differing opinions on this. Personally, I would use an apostrophe only if omitting it would lead to confusion. Probably in most contexts, 0s and 1s are fine without the apostrophe. Ebony Jackson (talk) 01:20, 25 December 2013 (UTC)

Apostrophes are also used in English to denote contraction, and I think of any numeral followed by "s" as a contraction. Thus "1980's", "0's", "1's", but "nineteen eighties", "zeros", "ones". Sławomir Biały (talk) 09:46, 25 December 2013 (UTC)

I thought that might be a reason to use 0's and 1's, but then 1980's is incorrect per the MOS and every other guide I've seen ever.--Gilderien Chat|List of good deeds 11:14, 25 December 2013 (UTC)

Yes, I agree; I would definitely favor 1980s over 1980's. Ebony Jackson (talk) 14:37, 25 December 2013 (UTC)

I suppose that's right. I'm not sure what the general rule is, then, but "0s" and "1s" definitely seems wrong to me. Sławomir Biały (talk) 15:40, 25 December 2013 (UTC)

Apostrophe#Use in forming certain plurals seems to say that neither with ' or without ' is really wrong, though I'd probably use the ' if pressed. To avoid controversy the real answer is spring for a few extra bytes and spell out "zeros and ones". --RDBury (talk) 03:23, 27 December 2013 (UTC)

"1980's", with an apostrophe, is the form used by the New York Times, but I think most others write "1980s". If you're abbreviating "greatest common divisor" as gcd and cumulative distribution function as cdf, the the apostrophe seems to serve a purpose. If you write those with capital letters then that's not needed: GCDs, CDFs. Michael Hardy (talk) 21:34, 27 December 2013 (UTC)

Actually, the New York Times too favors the usage without the apostrophe. Searching the newspaper at its website turns up far more references to "1980s" than to "1980's". Similarly, "0s and 1s" is more common than "0's and 1's". And in fact, their style guide as of November 14, 2011 says "do not use apostrophes for plurals of abbreviations without periods, or for plurals formed from figures: TVs, PCs, DVDs; 1990s, 747s, size 7s." Ebony Jackson (talk) 02:25, 28 December 2013 (UTC)

Their 2011 style guide must be a change in policy. Michael Hardy (talk) 00:08, 8 January 2014 (UTC)

Question regarding well-defined vs. completely determined

There is an en wikipedia article on well-defined. However, I did not find one on "completely determined". I have found that these terms are sometimes not well understood by our educators, perhaps even by myself. For example, I might (very succinctly) say "For a right-angled triangle with acute angle x, we define sin(x) to be the ratio of the length of the side opposite x to the length of the hypotenuse. The number sin(x) is well-defined because a right-angled triangle is completely determined up to similarity by the size of the angle x and similarity guarentees that this ratio is a unique constant.". Please understand that I am trying to work in the two terms in one sentence (and not get caught up in the sentence itself). I believe this sentence illustrates the difference between the two terms.

I think it is important to give our educators (particularly elementary school educators who tend not to be mathematicians) a usable, well-defined term for them to be able to say something like "A rectangle is completely determined by its width and height, but a triangle is not.". Then we can consistently use this terminology.

If we think an article on "completely determined" might be useful, perhaps we could share some ideas on what it should contain.

Thank-you for reading. Lfahlberg (talk) 06:05, 7 January 2014 (UTC)

Per WP:NOUN, adjectives as article titles are generally discouraged. I'm actually not very happy that there is such an article as well-defined, and I certainly don't want to compound the problem. (What to do with the existing content at well-defined is a difficult problem, though.) --Trovatore (talk) 21:02, 7 January 2014 (UTC)

---

I understand your point about adjectives as article titles, particularly with respect to the term "completely determined". That is why I wrote this section with my question.

---

With respect to "well-defined", I might point out (after just briefly searching) that

• Weisstein. Eric. CRC Concise Encyclopedia of Mathematics. has articles entitled: Well-defined and Ill-defined. (Many of the articles in Wolfram's Mathworld are written by Weisstein, e.g. http://mathworld.wolfram.com/WellDefined.html)
• Clapham, C., et.al. Oxford Concise Dictionary of Mathematics. has articles entitled: Ill-conditioned and Well-conditioned.
• http://planetmath.org/welldefined

These appeared (again after only a cursory examination) to be the only articles in these sites with "adjective" titles.

Also, there are plenty of "answer articles" online where the question "What is the meaning of the mathematical term well-defined?" has been asked.

So while it might need work (perhaps including a lower-level example), I do think the article well-defined is not a problem and should not be deleted.

---

On the other hand, the current alternative with respect to "completely determined" (which does not necessarily mean that this is a bad idea) is to do what is done in wikipedia and elsewhere by other authors (and myself) and that is to use the term and then explain its meaning in the article itself, e.g. "A triangle is not completely determined by its width and height. In fact, there are infinitely many non-equivalent (non-congruent) triangles having the same width and height.". This is certainly adequate.

I point out that there are en wikipedia mathematics articles where the term "well-defined" is used (but neither well-defined nor linked) and that my question here about "completely determined" came about because I also saw the term "fully determined" used in the context of "completely determined" in an en wikipedia math article and thought we might want to go for some consistency. Lfahlberg (talk) 13:18, 8 January 2014 (UTC)

Not having thought very hard about it, it seems to me that the mathematical use of "completely determined" is decipherable by a person with no mathematical training, i.e., I think the jargony use of this phrase is an example of very transparent jargon. So for this reason I am inclined to say we don't need an article about it. (As I said, though, I haven't thought hard about this.)--JBL (talk) 14:30, 8 January 2014 (UTC)

I think this is an interesting point. In my mind, the phrase "completely determined" is a casual way of saying "there exists a bijection" (or sometimes something stronger, like an isomorphism or a diffeomorphism or whatever). The phrase "fully determined" would mean the same thing. So would many other statements like, "Knowing the height and width of a rectangle tells us which rectangle it is up to congruence." All of these could be made more explicit. I think the problem is that, while all these informal statements may be clear to the experienced reader, they may be opaque to the reader who doesn't already speak mathematics.

I don't think that there is a single good solution to this problem. Too-formal mathematics writing is clumsy, verbose, and indecipherable. Too-casual mathematics writing is vague, imprecise, and indecipherable. Every article needs to strike a balance, and the proper balance will depend on the article. Writing a page on "completely determined" might help some readers of some articles, but it will not help when the editor uses "fully determined" or "tells us" or some other casual phrase. In case there is a situation where "completely determined" is really confusing, it might help to either rewrite that portion of the article or link "completely determined" to bijection (or another appropriate article). Ozob (talk) 14:33, 8 January 2014 (UTC)

thanks to everyone who responded. i found each comment in this discussion most useful. Article specfic with perhaps for lower level sections the term "uniquely determined" might even be good and for higher level sections linking. Much appreciation. Lfahlberg (talk) 15:24, 8 January 2014 (UTC)

I would just point out, since you mentioned MathWorld, that MathWorld specifically is in many cases a great example of what not to do. MathWorld's definitions are in many cases idiosyncratic, bordering on neologistic, and no warning is given to the reader that the terminology being used may not be part of standard mathematical usage.

The problems of the well-defined article go well beyond its name being an adjective. The article abstracts a general concept from particular usages; an encyclopedia should not do that. I don't have a good solution to the problem at this time, but there really is a problem. We should not make it worse by repeating the mistake. --Trovatore (talk) 20:11, 8 January 2014 (UTC)

Apparently, my last response was unclear. I was summarizing that it seems the consensus (including my own) that no additional article should be created and that the term (uniquely, completely, fully, etc.) "determined" be used as needed in the writing of specific articles at the level of the reader of the material with a brief explanation or link (if necessary). I appreciated this discussion as it had clarified for me some aspects of the terminology "determined" with respect to different levels of mathematics and readers, e.g. I too think a pupil or elementary school teacher who is consulting this encyclopedia can understand the term "uniquely determined" with say a link to the keyword of congruence, similarity, etc. Lfahlberg (talk) 01:58, 9 January 2014 (UTC)

No, that's fine; I was responding more to your comments on the well-defined article.

BTW, even if there were a problem understanding "uniquely determined", it still wouldn't follow that we should write an article about it. Encyclopedia articles should be about something. They shouldn't be written just to document jargon. --Trovatore (talk) 02:03, 9 January 2014 (UTC)

How to handle CMP index in cite template

Is a CMP ("Current Mathematical Publications"?) index a useful piece of information to retain, and if so, how should it be handled in the cite template? Thanks! Lesser Cartographies (talk) 03:53, 9 January 2014 (UTC)

TeX rendering on Firefox

It seems the newer versions of the Firefox browswer fail to display many of our pages correctly. For example:

$\left({\frac {1}{2}}\sum _{k=1}^{\ell }\right)$

versus

$({\frac {1}{2}}\sum _{k=1}^{\ell })$

The two displays above look quite different from each other on the chromium browser I'm typing this one, and that is as it should be, but they look identical to each other on recent versions of Firefox.

$3+\cdots +3,\quad 3,\ldots ,3$

versus

$3+{\cdot }{\cdot }{\cdot }+3,\quad 3,{.}{.}{.},3$

On the chromium browser, the last two displays above look quite different from each other in just the way they ought to. On Firefox, the \ldots look identical to the {.}{.}{.}. That should not happen. On Firefox, the \cdots and the {\cdot}{\cdot}{\cdot} do look somewhat different from each other, but the dots should be closer together in the latter version, and they're actually a bit farther apart in the latter version.

Should we:

(1) Alter our ways of doing things here (how?)?; or

(2) Complain to Firefox; or

(3) Something else?

Michael Hardy (talk) 00:23, 8 January 2014 (UTC)

That doesn't seem like a large problem to me, since the default for math is LaTeX PNGs. Firefox MathML bugs should definitely be reported, though I'm not sure anyone is actively maintaining FF's MathML support these days. Gutworth (talk) 00:49, 8 January 2014 (UTC)

My quite recent Firefox 21.0 displays these two pairs differently, which is supposedly correct: the first pair differs only by the size of parentheses (smaller in the second example); the second pair differs by spacing between dots (smaller in the second example). There must be something else/additional in your system which causes the identical rendering. No such user (talk) 13:46, 8 January 2014 (UTC)

FF 21.0 is recent? I have FF 26.0. I have the MathJax option set, so my view may not be typical. — Arthur Rubin (talk) 15:16, 8 January 2014 (UTC)

You're right, I've lost the count since 15. However, I'm writing this from another computer using FF26, and rendering is much the same. And I have MathJax turned on, too. No such user (talk)

I have the latest version of Firefox (i.e. 26.0) and the differences you see in chromium are quite visible in my Firefox browser. JRSpriggs (talk) 07:09, 9 January 2014 (UTC)

AfC submission

Here's a new one for you. Thanks, FoCuSandLeArN (talk) 13:22, 7 January 2014 (UTC)

And another one. FoCuSandLeArN (talk) 20:37, 8 January 2014 (UTC)

Both articles (Integral of inverse functions and Approximate tangent space) are very good starts and ready for mainspace. I'll take the liberty of moving them, with the correct capitalization. M∧Ŝc²ħεИ_τlk 07:34, 9 January 2014 (UTC)

Brouwer fixed-point theorem

This article is rated Start class. Surely it deserves a little bit better? YohanN7 (talk) 02:16, 9 January 2014 (UTC)

I've changed it to B class, although with that many references, it may be a good article candidate. I'll look at it more, but anyone can nominate it if it satisfies the requirements. — Preceding unsigned comment added by Brirush (talk • contribs) 02:56, 9 January 2014 (UTC)

Thanks. YohanN7, please feel free to change the ratings of articles when you see them misrated like this. —David Eppstein (talk) 03:03, 9 January 2014 (UTC)

The GA folks will whine about there not being one reference per section/paragraph/sentence. Sławomir Biały (talk) 12:16, 9 January 2014 (UTC)

Poisson point process

Because several existing articles link to it, I've just created a new article titled Poisson point process. Our article titled Poisson process is only about one-dimensional Poisson processes. It could bear a lot of expansion. One could also rewrite the Poisson process article so that it covers this, but that would take a lot of rewriting. Michael Hardy (talk) 21:28, 9 January 2014 (UTC)

For the record, here are the currently existing non-template links to the article:

• Poisson process ‎ (links)
• Wikipedia talk:WikiProject Mathematics ‎ (links)
• Talk:Shot noise ‎ (links)
• Campbell's theorem (probability) ‎ (links)
• Template:Stochastic processes ‎ (links)
• Point process operation ‎ (links)
• Nearest neighbour function ‎ (links)

If I'm not mistaken, soon every article that uses the "stochastic processes" template will be listed among these links, and there will be no way to tell which ones are non-template links (or have they changed that now?). Michael Hardy (talk) 21:34, 9 January 2014 (UTC)

Invitation to User Study

Would you be interested in participating in a user study? We are a team at University of Washington studying methods for finding collaborators within a Wikipedia community. We are looking for volunteers to evaluate a new visualization tool. All you need to do is to prepare for your laptop/desktop, web camera, and speaker for video communication with Google Hangout. We will provide you with a Amazon gift card in appreciation of your time and participation. For more information about this study, please visit our wiki page (http://meta.wikimedia.org/wiki/Research:Finding_a_Collaborator). If you would like to participate in our user study, please send me a message at Wkmaster (talk) 12:51, 10 January 2014 (UTC).

New functional analysis template added to many articles

A new user Mgkrupa has created a template for functional analysis topics and added the template to nearly 100 articles in short order; an example is Functional analysis itself in the footer of the article. I mostly ignore templates and don't know the policy on these, but some may want to check the work. --Mark viking (talk) 05:54, 10 January 2014 (UTC)

My policy is that if the template is conceivably useful to someone, then I ignore it completely if it's only a footer. I don't think the functional analysis footer is really all that bad, so I would be inclined to leave it in as it might make navigation useful for someone. (Things become a bit different with navboxes placed within the article itself: I am generally opposed to them, and they are impossible to ignore because of their placement.) Sławomir Biały (talk) 12:26, 10 January 2014 (UTC)

I wouldn't ignore all footers because of the risk of template creep, but this one seems well designed and meets the criteria for a good navbox. RockMagnetist (talk) 16:55, 10 January 2014 (UTC)

Cocycle

Cocycle is problematic on a number of levels. It has a footnote and a reference, elements which are not used on disambiguation pages, and the third line has no link, but appears to be an example or a formulation not found elsewhere in the encyclopedia. Is there a primary topic here? Is there a missing topic? bd2412 T 17:53, 12 January 2014 (UTC)

I agree, this article is not very good. It might be best to redirect to chain complex. Ozob (talk) 18:00, 12 January 2014 (UTC)

Topology good aeticle review

The reviewer for topology has asked for a second opinion for the use of a mathoverflow post as a reference. Does anyone have a suggestion for an alternate reference for the definition of geometric topology or an argument in support of this internet source?Brirush (talk) 19:28, 12 January 2014 (UTC)

How about [2] as a reference? Ozob (talk) 21:45, 12 January 2014 (UTC)

Quotition

We have a new article titled Quotition. Apparently the concept is current in the field of mathematics education. In the Oxford English Dictionary I find quotum and quotity, and quotient, all three of which seem related, but I don't find quotition. Michael Hardy (talk) 23:10, 14 January 2014 (UTC)

It seems to be a well-established concept. I added two books to the references - one from 1916 and one from 2006. There were plenty more. RockMagnetist (talk) 23:35, 14 January 2014 (UTC)

Problems with user: Incnis_Mrsi

I am respectfully requesting from this community that User:Incnis_Mrsi not be allowed to respond to me or pages I edit. I realize that this person has a long-standing membership in this community and I do not. This person responses towards me are neither professional nor respectful in any way and constitute personal attacks on me. As just recent examples, I tender the following responses to my conversations in the following talk pages: http://en.wikipedia.org/wiki/Talk:Linear_equation#no_citations http://en.wikipedia.org/wiki/User_talk:Lfahlberg#Constant_function

Today I edited the page: https://en.wikipedia.org/wiki/Constant_function. The response to my edits to this page by User:Incnis_Mrsi illustrates clearly that the intent of this person is not wikipedian nor - and more importantly - is it intended in the spirit of readability and usefulness to the user of wikipedia. I have worked on other pages here in such a spirit of community and collegiality that this attitude is simply not understandable nor do I think this is acceptable.

History of today's edit. In August 2013, I added to the talk page suggestions about these changes and no one objected to my notes. There were no citations in this article; none. I researched the topic, added appropriate definitions, images and 7 citations, correctly processed as per cite book and cite web as required by wikipedia. I would also note that I visited many other translation pages of this page before making changes to ensure that not only was my research correct, but also that it agreed with the globally accepted definition, explanation and use of the term "constant function".

Further, I specifically requested in the talk page that the community help with improving this page with respect to readability and usefulness.

I point out that I could not add the planetmath citation to the definition in section 2, namely http://planetmath.org/constantfunction since this page does not contain citation information as required by wikipedia. However, the definition stated in this section here is simply a formalized version of the definition given at the beginning and for which there are 3 proper citations. The examples and images given in this section are just that. Examples that directly apply the definition and images. They certainly do not constitute research.(Section 3 is not my work; it still has no citations, but I assumed in good-faith that it is correct and did not alter it in any way and apparently this IS acceptable to User:Incnis_Mrsi)

Thank-you for your consideration of my request. 19:45, 12 January 2014 (UTC) — Preceding unsigned comment added by Lfahlberg (talk • contribs)

This isn't really a forum for complaints about specific Wikipedians unless it's a request for additional patrolling. Please read the Wikipedia:Dispute resolution guideline for help on how to resolve issues with other Wikipedians. --RDBury (talk) 17:43, 13 January 2014 (UTC)

I agree that the interaction of editors in Wikipedia could be better organized, but it is organized as it is. There is no firm authority, so, any editor can intervene if s/he sees a blatant violation of established editing norms. Even Incnis_Mrsi with his nasty habits and poor English, unless blocked. By the way, there are many things that I hate in Wikipedia. For example, I hate when someone wipes out a carefully prepared edit with a hypocritical and cynical summary. I experienced it from certain (third-party) user of this WikiProject not a long time ago, and now I am unsure that will restrain myself from saying him “fuck you” upon the next conflict. The difference is not about a “long-standing membership” here that some guys have whereas Mr. Lfahlberg hasn’t. The difference is about guys who can edit articles in this (probably mismanaged) project, and those who begin to look for scapegoats. The Wikipedia community is hypocritical, unjust, libellous, and inherently illiberal. It is not aimed to defend anybody’s rights or honour. Incnis Mrsi (talk) 19:30, 13 January 2014 (UTC)

I don't see anything actionable here. You Lfahlberg improved Constant function but made a few mistakes. Incnis Mrsi further improved it by correcting the mistakes. That's how Wikipedia works, improvement upon improvement. It's also how editors learn; as editors can dive into editing without any training or reading any instructions new editors often make mistakes. Being corrected by other editors is part of the learning process of being an editor, and for many editors never stops as they are always trying and learning new things.--JohnBlackburne^words_deeds 20:01, 13 January 2014 (UTC)

Oh, and if Incnis is a little bit rude on occasion - just be a little bit rude yourself in return. It will spice up a gloomy day in January. He'll take no offense. Nor should you. YohanN7 (talk) 19:40, 14 January 2014 (UTC)

I prompt Lfahlberg to cease various insinuations and start to learn WP:consensus-building procedures. All what I say is my opinion. It isn’t an authoritative review of Lfahlberg’s contributions. Aforementioned Lfahlberg’s activity apparently is aimed to compel me to shut up. Will Lfahlberg’s articles become better if the criticism became suppressed? Incnis Mrsi (talk) 16:11, 15 January 2014 (UTC)

Partial derivative : how to read and how to compute it ?

${\frac {\partial }{\partial {z}}}{\frac {\partial }{\partial {z}}}f_{c}^{p}(z_{0})$

I do not know what it means ? --Adam majewski (talk) 17:46, 12 January 2014 (UTC)

Differentiate twice with respect to z, keeping all other variables constant (which you have not indicated), then substitute z = z₀ into the result (after differentiation, not before). This does not look like a function of more than one variable, so only ordinary derivatives are needed. Have you read the partial derivative article? M∧Ŝc²ħεИ_τlk 17:50, 12 January 2014 (UTC)

It is different then second order derivative ? I have looked at this article, but I'm not good at it.

Another example from wikibooks : ${\frac {\partial }{\partial {c}}}{\frac {\partial }{\partial {z}}}f_{c}^{p}(z_{0})$

Does it mean : mixed second order partial derivatives ? TIA --Adam majewski (talk) 18:57, 12 January 2014 (UTC)

This talk page is for discussing how to improve Wikipedia mathematics articles. It is not a math help site. For help with mathematics, try Wikipedia:Reference desk/Mathematics. Good luck. Mgnbar (talk) 19:18, 12 January 2014 (UTC)

I would say that

$\left({\frac {d}{dz}}\,{\frac {d}{dz}}f\right)(z_{0}){\text{ and }}{\frac {d}{dz}}\,{\frac {d}{dz}}{\Big (}f(z_{0}){\Big )}$

mean two different things, and the second one is zero. Michael Hardy (talk) 00:55, 13 January 2014 (UTC)

OK. There are so many things here. Maybe add these to the page about derivative ( for example section notation ]] ?

Can you also check the pages related with derivatives  :

• Mandelbrot_set#Interior_distance_estimation
• Complex_quadratic_polynomial
• from wikibooks

TIA --Adam majewski (talk) 17:23, 13 January 2014 (UTC)

You want these pages listed at Derivative? Are we to list every article that uses derivatives at Derivative? There would be too many. Derivatives can be found all over Wikipedia. Mgnbar (talk) 20:47, 14 January 2014 (UTC)

No , I ask experts for checking these pages . ( I have edited my previous post ) . --Adam majewski (talk) 15:34, 15 January 2014 (UTC)

What do you mean by "Maybe add these to the page about derivative"? What specifically do you want checked on these pages? Mandelbrot_set#Interior_distance_estimation and Complex_quadratic_polynomial seem fine. The wikibooks article should be discussed there, not here. M∧Ŝc²ħεИ_τlk 19:56, 15 January 2014 (UTC)

AfC submission

Thank you for your help so far. This is another submission. FoCuSandLeArN (talk) 21:55, 16 January 2014 (UTC)

I installed the AfC script and accepted the article. -- Jitse Niesen (talk) 09:32, 17 January 2014 (UTC)

Thank you. Here's another one. FoCuSandLeArN (talk) 16:45, 17 January 2014 (UTC)

Wikipedia talk:Articles for creation/Chi-Squared Divergence

Dear mathematicians: This draft was never submitted for review at Afc. It appears to have references. Is this a notable topic? —Anne Delong (talk) 00:22, 20 January 2014 (UTC)

Hamilton Mathematics Institute

Is the article about the Hamilton Mathematics Institute in Dublin worth keeping? Someone suggested there is insufficient evidence of notability. Michael Hardy (talk) 17:53, 20 January 2014 (UTC)

List of algebras

Note: a stupid thread headline changed: this is not a discussion about the Help Desk. Incnis Mrsi (talk) 13:50, 20 January 2014 (UTC)

There's a discussion on the Help Desk about List of algebras. Please review List of algebras and if it's not needed, please address. Thanks. -- Jreferee (talk) 00:47, 20 January 2014 (UTC)

IMO, List of algebras must be merged into Algebra#Topics containing the word "algebra". By the way, in relation with this discussion an editor restored an old version of Algebra (disambiguation) in place of a redirect to Algebra, and has reverted twice my revert. IMO, this version of is a WP:DABCONCEPT article, and this disambiguation is better explained in Algebra. D.Lazard (talk) 10:57, 20 January 2014 (UTC)

To me it's very strange to emphasize the "not necessarily associative" algebras. Surely the "necessarily associative" algebras are a much more important distinguished subclass of these. Sławomir Biały (talk) 12:44, 20 January 2014 (UTC)

On the other hand, Heyting algebra is not even an algebra over a ring. I’d prefer to say something as “This is a list of various structures that match the most general definition of the term "algebra". Most of them are algebras over specified rings (or fields)” and add comments to list items, but I hesitate to save it. Incnis Mrsi (talk) 13:50, 20 January 2014 (UTC)

Maybe one should have an article titled List of algebras over a ring or something like that, and one or more separate lists of other sorts of objects called algebras. They would all exclude things in which the word "algebra" is a mass noun rather than a countable noun (i.e. senses in which it admits no plural form), but would list only _objects_ called algebras. Michael Hardy (talk) 17:57, 20 January 2014 (UTC)

Thoughts on this wikiproject

I have been trying to understand the actual problem. I will be specific first, generalize below.

Just for a moment, think back to when you were 14 years old and learning for the first time about functions and graphing. Let us think about something really simple, e.g. the y-intercept. (Excuse me while I head IM off at the pass before he sends me a note telling me that he has already warned me once about using a dash in math text and tell him that this term is standard in the us, uk and au.) Anyway, this term is defined in EVERY f-ing encyclopedia, textbook, online resource,... that exists (here I am actually thanking IM). So:

• the concept of y-intercept should be (and is) acceptable as the subject for a wikipedia article
  • even the "we do not need to cite anybody and our classification system is perfect for all mathematics resources" planetmath.org must agree that this is a legitimate topic (while of course relegating it to their joint category of "mathematics education & mathematics history".)
  • this concept is CLEAN. it is limited to a rvf of rva f:R->R so planetmath.org is not interested in it and the article stands.
  • Of course, there are no decent categories for it in the portal It is not an algebra. if one puts it into elementary functions, the poor pupil or teacher linking to that category would freak out. Math ed, that's it.

But, the article stands. No problem yet.

Now, being both maths and wiki people, we want to connect this article wrt to maths and the wiki. What is the very first use of y-intercept? Of course, it is a constant or linear function.

Big problem now. Now we have hit the HMP of planetmath.org and content on a page marked by planetmath is carefully monitored to be only their content.

You don't believe me? Read my note User_talk:David_Eppstein#Constant_function_edits who simply deleted an edit (that i had previously discussed in the talk 6 mos before and noone responded) stating unsourced (it was actually "sourced" planetmath -omg) and unhelpful (interesting new math proof term). Notice no response. (Concensus building - my ass.)

But many incoming editors (including obviously myself) don't know about the HMP. They have not yet connected the dots between the content of the portal and (in my case) a 10 year history attempting to get an adequate classification system for resources of usable content for teachers working with our children so that someone who needed the resource could actually find it. (~8-10 years ago i wrote merlot.org (who were then begging for OER interactive resources) and asked it they could possibly subdivide their tag category "math education" into 3 subcategories for elementary, middle and high school and received a wonderfully arrogant letter stating that the classification system of planetmath was perfect as is.)

Well, I finally connected the dots. And as I too was once young and only interested in "pure math" and bored with this kind of discussion, I understand that you probably don't care. But, this is a real problem.

Wikipedia math under this direction is not providing very many quality, usable resources for anything under 3rd year theoretical mathematics.

This is clear from the many blogs, online discussions, tweets, etc showing the frustration of the many varied people accessing our materials. Our kiddies (Including engineering students) and their teachers go to places like the Khan academy. (I am not disparaging this resource, but it often times does not provide mathematically correct, quality, consistent and connected information.)

At this time, I am not longer interested in continuing to challenge this attitude here. Been there, tried that - failed even here. I have more than paid my debts to our real educators (the ones in the crowded classroom squeezed by every possible side telling them that they are not real maths (this community), not real teachers (the educators with their philosophies and sample sets of n<=20) and statistically giving up teaching after 3 years.

I KNOW that there are members here that believe as I do - that our beginning and intermediate mathematics needs to be on a more-than-equal footing with higher maths (also that numerical mathematics needs to be properly integrated here). I appeal to you to change the attitude of this wikiproject and portal to reflect this.

As always, thanks for reading and thinking about this. I return to creating useful resources for the peons. Lfahlberg (talk) 07:28, 21 January 2014 (UTC)

Zeta(-1)

I'm not sure what's going on: has zeta(-1) been featured in the yellow media recently? Anyway, there is a discussion at Talk:Riemann zeta function#Zeta(-1) that would benefit from input of people who know the score. Sławomir Biały (talk) 20:08, 21 January 2014 (UTC)

It was started by [3], then picked up by various social media. Ozob (talk) 03:40, 22 January 2014 (UTC)

AfC submission

Another relevant submission. Regards, FoCuSandLeArN (talk) 14:36, 21 January 2014 (UTC)

I moved it to mainspace, helped by comments from Mark viking. -- Jitse Niesen (talk) 12:16, 22 January 2014 (UTC)

Feedback request: VisualEditor special character inserter

The developers are working on a character inserter for WP:VisualEditor. Their focus at the moment is on about 50 Wikipedias that have complex language requirements, like Welsh (but not like Chinese, which is a different kind of complexity). There is a special character inserter tool in VisualEditor now. They would like to know what you think about this tool, especially if you speak languages other than English—and mathematics isn't exactly what they had in mind (because an extensive TeX-based formula editor is the main way to deal with mathematics), but it does provide access to some mathematics symbols. So if you are interested in trying it out, please do so, and then let them know what you think of their choices for math symbols. The steps are easy:

• If you haven't already opted-in, then opt-in to VisualEditor by going to Special:Preferences#mw-prefsection-betafeatures and choosing "VisualEditor". (While you're there, you might want to enable mathematics formulas, too.) Save your preferences.
• Edit any article or your user page in VisualEditor. See the mw:Help:VisualEditor/User guide for information on how to use VisualEditor.

The “insert” pulldown on the task bar of VisualEditor will lead you to the ‘⧼visualeditor-specialcharacterinspector-title⧽’ tool.

This is the ⧼visualeditor-specialcharacterinspector-title⧽ inserter. Your feedback on this tool is particularly important.

To let the developers know what you think, please leave them a message with your comments at the feedback thread on Mediawiki.org or here at the English Wikipedia at Wikipedia:VisualEditor/Feedback. It is really important that the developers hear from as many editors and as diverse as set of uses as possible. Thank you, Whatamidoing (WMF) (talk) 00:10, 23 January 2014 (UTC)

Cone

Must a cone have a circular cross-section? The article Cone initially says that it must, but other statements sprinkled throughout seem not to assume this, or seem unnecessarily vague if it is true. I raised this on the talk page a while ago, but no takers. Does anyone here have a view? 86.128.3.252 (talk) 18:40, 22 January 2014 (UTC)

The article asserted in the first sentence that the cross section is "typically" circular; this means "often" or "in the most common cases" and is perfectly consistent with the rest of the article. I've now substituted the phrase "frequently, but not necessarily," which hopefully is clearer (but I do not object if someone has a better phrasing). --JBL (talk) 19:37, 22 January 2014 (UTC)

The statement that you have changed refers to the base, not a general cross-section. I'm talking about the statement in the next paragraph where it says "such that there is a circular cross section". A cone can have a circular cross-section but be lopped off at an angle such that the base is not circular. The wording "a circular cross-section" seems to be designed to accommodate this case. My question is whether a cone has to have a circular cross-section, not whether the base has to be circular. 86.128.3.252 (talk) 20:14, 22 January 2014 (UTC)

The cross-sections parallel to the base are all necessarily of the same shape as the base. Now that I've read the full lead ( ;) ) I agree with you; I have removed the (uncited) statements that the cross-sections need to be circular. --JBL (talk) 20:34, 22 January 2014 (UTC)

Thanks, I should have mentioned this though, which says that a cone does have to have a circular cross-section. Is that source wrong? 86.128.3.252 (talk) 20:50, 22 January 2014 (UTC)

As with many things, there are different meanings of the same word; often, "cone" means "circular cone," but our article (as you note) is written about a more general class of objects, so the lead paragraph should match it. As you can probably tell, I have not carefully gone over the article or anything; perhaps the lead (and/or the rest of the article) should give more emphasis to the circular case, since this is (in geometry) the most common one, but the word "cone" is also widely used in the more general sense. --JBL (talk) 21:00, 22 January 2014 (UTC)

Right, the word may be used differently by different people, but our article should give the mathematically correct definition (and explain as necessary if it going to extend this to a kind of layman's definition). Normally I would assume that the MathWorld site was mathematically correct, but maybe not in this case ... 86.128.3.252 (talk) 21:16, 22 January 2014 (UTC)

(edit conflict) As far as I remember, a cone with a conic section as basis has always a circular cross-section. Nevertheless I do not remember of a simple proof of that fact. On the other hand, a cone with another curve as basis does not have any circular cross-section.

This article has another issue: depending on the context, "cone" may have various meanings, all mathematically correct, which should be disambiguated in the lead: a cone may be the solid or the surface delimited by the basis and the vertex. It may have a circular basis or have any curve as basis. It may be the surface generated by the rays sharing the same endpoint and cutting a curve. It may be the surface obtained by prolongating these rays into lines. It may also be the union of any set of rays (or lines) sharing a fixed endpoint (or point). All these notions are commonly called "cone" in mathematical texts, and only the context allows to disambiguate. Thus a WP:DABCONCEPT section seems to be needed here.D.Lazard (talk) 21:33, 22 January 2014 (UTC)

Note that the Cone (disambiguation) DAB page already exists and is accessible from a hatnote at the top of the Cone page. DABCONCEPT pages are useful when there is no one dominant usage of the title. But cone, as the geometric object, seems dominant to me. --Mark viking (talk) 22:14, 22 January 2014 (UTC)

Perhaps it's just me, but I thought the base of a cone did not have to even be two dimensional, e.g. the code of a point is a line segment, the cone of a line segment is a triangle, the cone of an n-simplex is an (n+1)-simplex. Has anyone else seen that usage or did I make it up? --RDBury (talk) 03:35, 23 January 2014 (UTC)

What you describe sounds like a cone of a topological space, described at Cone (topology). --Mark viking (talk) 03:52, 23 January 2014 (UTC)

I've seen that usage. Michael Hardy (talk) 04:25, 23 January 2014 (UTC)

• Thanks, the article is less of a muddle now that the statements requiring a circular cross-section have been removed. I spotted later in the article "The center of mass of a conic solid of uniform density lies one-quarter of the way from the center of the base to the vertex, on the straight line joining the two." This statement could do with tightening up with regard to cones whose bases have no obvious "center" -- either to exclude those cases if they are more complicated, or to refer to the "center of mass" of the base if that method always works. 81.159.106.14 (talk) 14:36, 23 January 2014 (UTC)

Distance from a point to a line and Perpendicular distance

These two articles have been around for a while and except for a few sentences in the lead of the second, their content is pretty much the same (or could easily be made so). It seems to me that a merge is in order. The question is which way should the merge go? I am not happy with either possibility, which is why I am bringing the subject up here. The distance from a point to a line article consists of several different proofs of the same 2-dimensional formula. This article was considered for deletion not too long ago, and several of you argued to keep it (but it doesn't look like anyone has seriously worked on it). I fixed a couple of proofs that had gotten garbled, but to improve the page I think we need to generalize the topic rather than provide more and better proofs of this simple formula. The Perpendicular distance article provides yet another proof of the 2-dimensional formula, and then states and proves a generalization to a formula for the distance between a point and a flat. This article has no references and no diagrams. Neither article contains a calculus based proof (or any other type of proof) that the shortest distance is along a perpendicular (but it is clearly assumed in each article). I think that at least the 2-dimensional proof would not be too far off the level of these articles. I also think that "perpendicular distance" is just a terrible title. My ideal solution would be to merge both articles into a new article, Distance from a point to a flat, but that title would not resonate well with the level of the readers of this article. I am looking for comments, suggestions, etc. Thanks. Bill Cherowitzo (talk) 18:28, 25 January 2014 (UTC)

I converted perpendicular distance into a set-index article listing four other articles (including the point-line distance one) on specific types of perpendicular distance. —David Eppstein (talk) 21:38, 25 January 2014 (UTC)

Thanks, I can work within that framework, but it still leaves open the issue of the weakness of the point-line distance article. There must be something we can do besides pile on proof after proof of the same result. Bill Cherowitzo (talk) 18:55, 26 January 2014 (UTC)

Pollock's conjecture(s)

I'm proposing a merge of the "tetrahedral" and "octahedral" conjectures into a single article. Any comments? (I only noticed this because one of them was added as a "See also" to Fermat polygonal number theorem, where I'm sure it should go.) — Arthur Rubin (talk) 21:20, 27 January 2014 (UTC)

In general I favor separate articles for separate topics, but in this case the topics are so similar, and what little there is to be said about them also so similar, that I agree that a merge makes sense. —David Eppstein (talk) 21:26, 27 January 2014 (UTC)

Working copy at User:Arthur Rubin/Pollock's conjectures. The only difference is that the Mathworld article "Pollock's Conjecture" points only to the tetrahedral conjecture, while "Octahedral Number" has mentions the octahedral conjecture. — Arthur Rubin (talk) 22:25, 28 January 2014 (UTC)

spelling of "l'Hopital's rule"

With this edit, a user has recently changed the text from explaining the difference as an "alternative spelling" to a "misspelling." This switches the tone from prescriptive to proscriptive, and so it deserves some attention. The previous version seems safer, if valid. Anyone know enough about French or math history to be able to verify it is an alternative spelling? Thanks Rschwieb (talk) 14:09, 28 January 2014 (UTC)

From Guillaume de l'Hôpital#Notes: "In the 17th and 18th centuries, the name was commonly spelled "l'Hospital", and he himself spelled his name that way. However, French spellings have been altered: the silent 's' has been removed and replaced with the circumflex over the preceding vowel. The former spelling is still used in English where there is no circumflex." Wikipedia is not a reliable source, but it does match my knowledge about French spelling, and makes sense. No such user (talk) 14:45, 28 January 2014 (UTC)

I agree. In French, the circumflex is (almost) always used for replacing a silent "s". The spelling "l'Hospital" is attested by the titles of two references of fr:Guillaume François Antoine, marquis de L'Hôpital and two external links of the same article. In fact, it appears that the correct spelling is "de l'Hospital", and that the other spellings are only common misspellings. Omitting the "de" is similar as talking about "Gaulle" instead of de Gaulle. However, "l'Hôpital rule" is a translation of the French "règle de l'Hôpital", and "règle de de l'Hôpital" is not so euphonic. D.Lazard (talk) 15:36, 28 January 2014 (UTC)

I don't think the spelling with a circumflex is an error. Some editions of his book appeared with this spelling. Tkuvho (talk) 15:49, 28 January 2014 (UTC)

Authors aren't known for misspelling their own names, so presumably this proves beyond any doubt that L'Hôpital's rule was in fact due to Bernoulli! Sławomir Biały (talk) 16:23, 28 January 2014 (UTC)

To editor Tkuvho: This depends if one accepts the modernization of the spelling for old people names. Thus "l'Hôpital" could be correct for the rule but not for the mathematician. Similarly, we have Vieta's formulas and François Viète (here, it is not modernization, but translation in another language). D.Lazard (talk) 16:50, 28 January 2014 (UTC)

Fontenelle's Éloge de M. le marquis de L'hopital (cited at the French page you linked) must have been one of the first to make the mistake of spelling it without an "s". Tkuvho (talk) 17:11, 28 January 2014 (UTC)

Thanks for all of the knowledgeable and prompt help. Rschwieb (talk) 15:26, 29 January 2014 (UTC)

AfC submission (Deep learning)

Wikipedia talk:Articles for creation/Deep learning. FoCuSandLeArN (talk) 13:41, 29 January 2014 (UTC)

There is already a deep learning article, apparently identical to the submission. Ozob (talk) 14:19, 29 January 2014 (UTC)

I (manually, as the script won't install until at least I close the browser) declined the submission, for that reason. The editor who requested the AfC submission replaced the mainspace article with his modified version. The question of whether this is a matter for WP:MATH is unclear, but I think this section should be considered closed. — Arthur Rubin (talk) 16:51, 29 January 2014 (UTC)

Mathematics and art

Mathematics and art asserts as factual many discredited fringe theories e.g. about the use of the golden ratio in Greek and Egyptian aesthetics. I tried a modest {{dubious}} tag, only to have the edit reverted and a (bad) source for these claims added. Any suggestions for a process that can get this cleaned up? —David Eppstein (talk) 01:27, 30 January 2014 (UTC)

The dubious tag is understandable--that's a pretty ambiguous sentence. It looks like Chiswick tried to be helpful by adding two references, which you don't like. He probably thought he answered your call for references and (along with the refs in the, e.g., Parthenon section) removed the dubious tag. I've worked with him on a symmetry article and he seems a reasonable fellow--why not discuss it with him on the article's talk page? --Mark viking (talk) 01:53, 30 January 2014 (UTC)

There are more citations in Mathematics_and_art#Parthenon. The only statement questioning the use of the golden ration does not have a citation yet. RockMagnetist (talk) 03:17, 30 January 2014 (UTC)

The various subsections of Golden_ratio#Applications_and_observations contain a bunch of useful references for someone interested in rewriting the article more skeptically. --JBL (talk) 04:10, 30 January 2014 (UTC)

Topology of uniform convergence

Topology of uniform convergence until minutes ago redirected to Polar topology. Someone created a new article titled Topologies of Uniform Convergence, with all those capital letters and the plural, and I moved it to Topology of uniform convergence, deleting the redirect in the process. So now we have

• Topology of uniform convergence, and
• Polar topology.

So:

• Should these get merged?

I'm not sure. The article Topology of uniform convergence deals with the case where the dual pair is (X, X') (i.e. with Y = X' in the polar topology article). So depending on what kind of presentation the reader is looking for, they might want one page but not the other.Mgkrupa (talk) 17:57, 30 January 2014 (UTC)

Also, thank you for your improvements on the article. Mgkrupa (talk) 18:14, 30 January 2014 (UTC)

• What work should be done on the new article, which is longer than the old one? I am not comfortable with the intro paragraph, since the first sentence doesn't even mention the term topology of uniform convergence. Michael Hardy (talk) 04:51, 27 January 2014 (UTC)

Polar topology is a better title, since "topology of uniform convergence" usually means something else. Sławomir Biały (talk) 12:11, 27 January 2014 (UTC)

I think that Polar topology is not the better title since the article topology of uniform convergence describes topologies, such as on the spaces L(X, Y), that are NOT polar topologies. These topologies are all known as topologies of uniform convergence. Also, you said that ""topology of uniform convergence" usually means something else", what do you mean by that? Mgkrupa (talk) 15:08, 28 January 2014 (UTC)

See the disambiguation page uniform topology. Sławomir Biały (talk) 16:52, 28 January 2014 (UTC)

Also, you're right that these don't seem to be called polar topologies in the literature. The standard term seems to be just the ${\mathfrak {S}}$-topology (see Bourbaki, Espaces vectoriels topologiques, III.§3). Sławomir Biały (talk) 00:41, 29 January 2014 (UTC)

From the page Uniform topology I see that one of the links is for Polar topologies, which this article covers, and the other two are for uniform convergence of real-valued (which this article also covers) or metric space-valued functions (which it doesn't cover) and finally for uniform spaces. In terms of sending people to the most general notion of uniform convergence the article "Topology of uniform convergence" should then just be a link to uniform spaces, or a dis-ambiguity link (although I think that this would just confuse anyone who doesn't already know what uniform convergence means and is simply trying to learn the basic notions). What if we were to call this article "Topology of uniform convergence of vector-valued functions"? A long name but also the most accurate.Mgkrupa (talk) 17:45, 30 January 2014 (UTC)

Wikipedia talk:Articles for creation/Phan Sequence

Hello, mathematicians! Last chance to read this old Afc draft before it disappears for lack of reliable sources. —Anne Delong (talk) 15:11, 30 January 2014 (UTC)

There is no chance that reliable sources exist for this sequence. --JBL (talk) 16:49, 30 January 2014 (UTC)

Yes, I thought so. Thanks. —Anne Delong (talk) 21:41, 30 January 2014 (UTC)