Wikipedia talk:WikiProject Mathematics/Archive/2007/Jan

Jasna Mađarević

Could someone take a look here? The article is about Serbian mathematician and is on AfD. TIA Pavel Vozenilek 02:32, 1 January 2007 (UTC)

Nonsense in Liber Abaci and Egyptian fraction

I'm getting very tired of repeatedly reverting Milo Gardner's changes (some under Milogardner (talk · contribs), some under various 172.x.x.x addresses) to Liber Abaci and Egyptian fraction, which I see as...not wrong exactly, but badly written, off-topic, giving undue weight to fringe points of view, and generally damaging to the usefulness and readability of the articles. And I'm a little worried that in doing so I'm becoming too single-minded myself and may be violating WP:OWN. Someone else want to give me a reality check, are his edits really as revert-worthy as I think they are? As an example, here is the diff from a sequence of 11 of his edits that I reverted with the somewhat abrupt summary "rv incomprehensible damage", which he took exception to. Was I too harsh? —David Eppstein 19:44, 1 January 2007 (UTC)

I don't have time to help out now, or in the coming days, but I'll just note that I had quite some problems with Milo on ancient Egyptian mathematics, see the talk page and also my user talk page. He obviously knows quite a bit about that, but he is unable to write it down in a format suitable for Wikipedia; specifically, his contributions are not neutral, but seem to be written in order to push certain theories which are not mainstream (e.g., remainder arithmetic). That's my own opinion, but it matches well with David's observations. -- Jitse Niesen (talk) 20:41, 1 January 2007 (UTC)

Without trying to follow the math, I observe that both articles contain a lot of derivations and many attempts to show the affinity of ancient and modern methods. Although we seem to tolerate a fair number of do-it-yourself derivations in the mathematics pages, strict application of policy would probably say that we should only repeat derivations published by others, and we should only make historical comparisons that have been published by others. On that view, both articles would probably become shorter. As to your specific revert in Liber Abaci, I have no complaints. The bibliography in Egyptian fraction looks huge, with many esoteric entries. Most of these are not cited in the text. It might perhaps be shortened by including a link to an online article with a good bibliography. EdJohnston 21:05, 1 January 2007 (UTC)

Gardner clearly has a lot of expertise on the subject, but his inability to write an intelligible sentence seriously detracts from the value of his contributions. I don't think you were too harsh. -- Dominus 23:52, 3 January 2007 (UTC)

Article listed for deletion

Wikipedia's mathematicians may wish to give their opinions at Wikipedia:Articles for deletion/List of books in computational geometry. Michael Hardy 01:54, 4 January 2007 (UTC)

Laplace-Runge-Lenz vector is now FAC

Hi, I just nominated Laplace-Runge-Lenz vector to be a Featured article candidate. Hopefully, you all think that the article is excellent and can support it. ;) But if not, please offer constructive criticisms on how it might be improved, which will be much appreciated. Thanks very much for your help! Willow 10:49, 31 December 2006 (UTC)

Is this not better described as Physics or Astronomy rather than Mathematics? JRSpriggs 05:23, 5 January 2007 (UTC)

Section Hyperreal number#Polynomial_ratio_construction

This section contains the following assertion

Let any relation of real polynomials in a single variable and their ratios hold when and only when they hold for all but a finite number of natural number values of the variable. The proof that first-order statements about polynomial ratios have the same truth value as corresponding first-order statements about standard real numbers is much the same as the proof for the ultrapower model, but requires only the use of a cofininite or Fréchet filter, not ultrafilters or the Axiom of Choice.

I find this dubious, although examination by a model theorist would be appreciated.--CSTAR 19:41, 3 January 2007 (UTC)

Hmmm. It's true for any infinite set of natural numbers, instead of merely all but a finite number of natural numbers. The result follows from the trivial result that any polynomial with an infinite number of roots is identically 0. I don't know if I could come up with a model-theoretic proof, though. — Arthur Rubin | (talk) 21:19, 3 January 2007 (UTC)

I can see how to reason thus if all the relations in question were elementary equations. If other relations, such as inequalities, are also considered, I'm less sure that it is trivial. Henning Makholm 22:45, 3 January 2007 (UTC)

It sounded what like he was saying that a particular mapping is an elementary equivalence embedding.

Your interpretation of this seems to be that for any n-ary relation R if I is an infinites subset of R

$R{\bigg (}{\frac {P_{1}(x)}{Q_{1}(x)}},\ldots ,{\frac {P_{n}(x)}{Q_{n}(x)}}{\bigg )},\quad \forall x\in I$

holds if and only if

$R{\bigg (}{\frac {P_{1}(x)}{Q_{1}(x)}},\ldots ,{\frac {P_{n}(x)}{Q_{n}(x)}}{\bigg )},\quad \forall x\in \mathbb {R}$

This is certainly true for polynomial relations (e.g. in case there is a polynomial Q for which

$R(s_{1},\ldots ,s_{n}){\mbox{ holds iff }}Q(s_{1},\ldots ,s_{n})=0$

But I don't think I understand what you said in general. Take

$n=1,P_{1}(x)=x,Q_{1}=1$

and

$R(s){\mbox{ being the unary predicate }}s>0$

x > 0 is true for an infinite set of integers, but it's certainly not true for all reals. Am I missing something?--CSTAR 21:51, 3 January 2007 (UTC) PS. Note also that the polynomial $x^{2}-x\geq 0$ for all integers x, but is negative in the open interval ]0,1[. --CSTAR 22:01, 3 January 2007 (UTC)

It makes more sense to me if read as: "If, for all choices of polynomials, the relation holds for an infinite (co-finte) set of integers (which may depend on the polynomials, then the relation holds for all reals". That is, you're supposed to take some closed formula and systematically substitute every quantification over reals into a quantification over polynomial ratios. So your counterexample is not a counterexample, because there are certainly polynomials for which $s>0$ do not hold for any integers at all. Henning Makholm 22:37, 3 January 2007 (UTC)

OK that I think I believe. There are still some details that need to be ironed out. Particularly, that this field is non-archimedean. But I guess the polynomial ratio x/1 will do the trick since for any (standard) integer n, x/1 - n > 0 holds. --CSTAR 22:54, 3 January 2007 (UTC)

This latter construction still doesn't look right; as x² != 2 is true for all rationals, (and hence all polynomials with integer coefficients evaluated over the integers), but not for all reals. Perhaps the only situations in which it makes sense is for polynomial equalities, in which case my first assertion is accurate. — Arthur Rubin | (talk) 14:04, 4 January 2007 (UTC)

OK this is even worse than I had originally thought; since it appears the language for which the mapping of the reals into polynomial ratios is an elementary embedding, cannot even include negation! --CSTAR 18:30, 4 January 2007 (UTC)

Hmm, it seems that trying to reason out the mathematical truth here is likely to confuse everybody, including every future editor who may try to figure out the claim. Let's revert to basic Wikipedia principles: we need to get a source for the claim, and then we can discuss whether the article accurately represents the claim made in the source. In the absence of sources, remove the claim. Henning Makholm 23:22, 4 January 2007 (UTC)

The complex plane

I've just finished adding quite a bit of new material to this article, which had been marked as a "stub". I would appreciate some feedback, either here or on my talk page. Is the article too long? Or just about right? I think this particular topic should be of some interest to the general reader, so I tried to keep it all as non-technical as I could. Does that approach make sense? Etc.

I could also use some advice on one thing. Rgdboer had raised a question about other meanings of the phrase "complex plane" on the article's talk page. So I added a section Complex plane#Other meanings of "complex plane" to discuss, briefly, the concepts of split-complex numbers, dual numbers, and the Cartesian product C×C. I'd like to write a little bit more for that section, but I'm not sure I understand these three objects well enough to figure out exactly what to say.

The first two "other complex planes" seem as if they'd hardly work well for analysis, except for some rather specialized applications in physics. And the two-dimensional vector space C×C is sort of tricky as well – right off the top of my head, I'm not even sure how to define a useful norm for that space. So I could use some help figuring out what else to say in that section of the article, if anybody here is willing to help.

Thanks! DavidCBryant 20:05, 6 January 2007 (UTC)

We have just been through a series of changes at Complex number#Conversion from the Cartesian form to the polar form concerning the computation of the argument of a complex number. The simplistic formula you give, $\theta =\arctan {\frac {y}{x}}$, is only correct when $x>0\!$. JRSpriggs 09:37, 7 January 2007 (UTC)

Thanks for pointing that out. I'm not sure what I was thinking; just absent-minded, I guess. I've changed it – you may or may not like this other idea, which is

$\theta =\arg(z)=-i\log {\frac {z}{|z|}}.\,$

I took a closer look at the article about complex numbers, and I'm not sure I agree with the way this problem is treated there. Maybe I'll jump in on that article's talk page. DavidCBryant 15:13, 7 January 2007 (UTC)

A bug?

I used to be able to reach the article Methods of computing square roots by going through the category Category:Root-finding algorithms. However, now when I look in that category, the article does not appear on my screen. None the less, the file has not been edited to remove it from the category. Nor has the category been changed in a way that would have that effect. Could this be a new bug in the software for displaying the contents of a category? Help! JRSpriggs 09:25, 7 January 2007 (UTC)

When I checked the category just now, the article was there (under M, of course). --KSmrq^T 12:13, 7 January 2007 (UTC)

I think it's working now. I removed an external reference to a web page right here that wouldn't respond when I pinged it. I'm not sure if the dead link was the problem, or if the Cyrillic characters displayed on the page were at fault, but the article shows up in the category list now. Oh -- why was the description of this site written in Russian? I can understand linking to foreign language web sites, but I don't understand why the link should be described in a foreign language on this end. DavidCBryant 12:30, 7 January 2007 (UTC)

PS to KSmrq – That's weird! I removed the broken link in the article, then sat here a while thinking about another problem before finally writing my response. The problem Spriggs reported was definitely showing up for me before I took the Russian language stuff out of the article. You checked the category while I was sitting here thinking about something else. DavidCBryant 12:37, 7 January 2007 (UTC)

Monty Hall problem

Monty Hall problem has been nominated for a featured article review. Articles are typically reviewed for two weeks. Please leave your comments and help us to return the article to featured quality. If concerns are not addressed during the review period, articles are moved onto the Featured Article Removal Candidates list for a further period, where editors may declare "Keep" or "Remove" the article from featured status. The instructions for the review process are here. Reviewers' concerns are here. Gzkn 10:57, 7 January 2007 (UTC)

The first reason cited for needing review? "Has one inline citation." Here we go again. --KSmrq^T 12:18, 7 January 2007 (UTC)

Collatz conjecture

I have seen a few references to a proof by this paper. It is listed in Québec Science's (ISSN 0021-6127) February 2006 special issue as one of the 10 top scientific breakouts made by Quebec scientists in 2006. Can somebody more knowledgeable than myself in maths look into that? Circeus 18:17, 10 January 2007 (UTC)

It doesn't prove the Collatz conjecture. What it does is to define a related probabilistic model in which a gambler, starting from an initial stake of A dollars, repeatedly flips a fair coin and based on the result replaces A with either A/2 or (3A+1)/2, and shows that this model leads almost surely to becoming broke. To me this seems very unsurprising. —David Eppstein 18:41, 10 January 2007 (UTC)

The paper requires a subscription, so I haven't seen it. What you describe seems to have a tenuous (or more accurately no) relation to the 3x+1 problem. It would seem to me, that to have some relation to the Collatz problem the parity of A should have some bearing on the next element of the sequence.--CSTAR 19:00, 10 January 2007 (UTC)

There is a free online paper by Alain Slakmon and Luc Macot. Also this online commentary (in French). My loose translation of Slakmon's summary:

"As we're talking about a probabilistic approach, we can't assert that there is an absolute proof of the truth of the conjecture. There remains a very small probability that certain numbers violate it," says Alain Slakmon. "But this possibility is now infinitely small". EdJohnston 19:45, 10 January 2007 (UTC)

Well, their solution is exactly as David Eppstein described it. I think that the commentary (CQFD) is hyperbole. I am very skeptical whether this really gets us any further to solution of this problem.--CSTAR 20:07, 10 January 2007 (UTC)

Missing articles

I was looking at the list of missing math articles at Wikipedia:Missing science topics/Maths1 and considering writing up some stubs (or perhaps a bit more) for a few topics, but it seems to me that many of these probably aren't sufficiently notable. For example, 0-free has an article on mathworld at Zerofree, and there seem to be one or two articles on it plus a sequence at the OEIS (which means nothing, really), but that probably doesn't satisfy the notability criteria. In fact, this is probably true of most of the terms in that list (even ignoring the ones that should probably be sections in other articles).

Am I right about this? Should I remove the links for topics that don't seem to be notable? Your opinions will be appreciated. --Sopoforic 02:39, 11 January 2007 (UTC)

Those lists are a compilation from such sources as MathWorld, PlanetMath, Springer's encyclopedia, etc. It is quite likely that a bunch of them are not notable. However, creating redirects to existing articles covering those concepts would be preferable to just removing those links from the lists I would think. Oleg Alexandrov (talk) 04:38, 11 January 2007 (UTC)

Well, sure, where possible. But in the example I cited, zerofree, we don't have any article to redirect it to. There are enough sources to make it verifiable, but it probably doesn't count as notable, in my opinion. My question is, granted that a thing is not notable, should I remove it from the list, or is it serving some greater purpose by being there? I was just going to remove such things, but I thought I should ask since I don't know if these lists are used for anything else than finding articles to write. --Sopoforic 14:37, 11 January 2007 (UTC)

You can remove unhelpful entries, no problem. The only issue is that when my bot updates those pages again, it may put those removed entries back. Perhaps, as you remove those entries, you could put them in a list for me, so that I make sure the bot remembers those and does not add them back the next time around. Oleg Alexandrov (talk) 17:11, 11 January 2007 (UTC)

An even better solution could be I think to just ignore the non-notable entries. It is very likely a good chunck of those redlinks will never turn blue. We could as well focus on the ones which are worth filling in and glossing over entries that don't appear relevant. Oleg Alexandrov (talk) 17:15, 11 January 2007 (UTC)

The problem with that is that if they are left on the list, other people will also have to evaluate them to see if they are notable, which is duplication of effort and ought to be avoided. --Sopoforic 17:39, 11 January 2007 (UTC)

This discussion got me curious enough that I went and reread the stuff about "Notability". Did you read the additional stuff at Wikipedia:Notability (numbers), Sopoforic? It looks as if "zero-free" might be notable, at least IMV. Oh – this reminds me of an old joke. Every positive natural number is unusual. The proof is by induction. Assume the theorem is false. Since the set of all positive natural numbers is bounded below, the set of all positive natural numbers that are not unusual must have an infimum x. But that's a pretty unusual property for x to have ... should we swap "unusual" with "not notable"?  ;^> DavidCBryant 17:26, 11 January 2007 (UTC)

Eh, the one that gives me difficulty is the first: "do mathematicians publish papers about it." Most anything that can be imagined will have one or two papers published about it, and zerofree only seems to have one that I'm sure is about that particular meaning (need to visit the library so that I can read the full text of the other articles). The notability guidelines generally go 'multiple non-trivial works' so I didn't think that just one paper was necessarily sufficient.

I suppose that I can just create articles for these and let AfD decide whether they're notable, should they be nominated for deletion, but I'd prefer not to waste effort. Still, it may be the best solution--I've probably already taken more time trying to decide whether zerofree was notable than I would have spent making a brief article on the subject. --Sopoforic 17:39, 11 January 2007 (UTC)

I prodded N-th triangular number squared a few days ago for notability. I would suggest prioritizing your new articles to create the most important ones first. It's a waste of everyone's effort to create articles if they are likely to be nominated for deletion quickly. CMummert · talk 17:48, 11 January 2007 (UTC)

While I agree that there are many non-notable items in these lists and many non-notable sequences in OEIS, I'm not convinced that N-th triangular number squared is a good example of such. The fact that the sum of consecutive cubes is a square, and moreover a square of a different important number sequence, is I think surprising and notable. OEIS gives seven references and a quick search found five more, including Stroeker, R. J., "On the sum of consecutive cubes being a perfect square", Compositio Math. 97 (1995), no. 1-2, 295--307, and Kanim, K., "The Sum of Cubes—An Extension of Archimedes' Sum of Squares", Proofs without Words, Mathematics Magazine, October 2004, 298-299. I don't have time to write more about this now (or fix up the article so that it is worthy of surviving your prod, which I think should include giving it a less cumbersome name — "squared triangular number" maybe?) but will try to take another look tonight. —David Eppstein 18:48, 11 January 2007 (UTC)

I agree that that article is on the edge of what is notable for a number and what is not; I happen to feel it is on the opposite side. Do you agree that a topic that is clearly more notable than that is notable enough? CMummert · talk 20:05, 11 January 2007 (UTC)

Yes. I also agree that the article as it stands isn't worth including; the bulk of the text (an easy inductive proof) is more filler than content. But I think it has potential to be above-threshhold. —David Eppstein 22:50, 11 January 2007 (UTC)

(The indenting gets to be a little extreme, I think ...) All kidding aside, Sopoforic, I' d like to offer a helpful suggestion or two. Those lists are certainly intimidating. I went through the first one only, and on a quick read-through hit just one item (Almost integer) that I've already thought of writing about. The idea I had there is that

${\frac {3^{12}}{2^{19}}}\approx 1.0136\,$

is the basis for Western music (well, the circle of fifths and Bach's well-tempered scale, at least), and that might provide an interesting tie-in to Ramanujan's continued fractions, which come a whole lot closer to being integers. Oh, yeah ... another interesting example is

$e^{3}\approx 20\quad \Longleftrightarrow \quad \ln 20\approx 3\,$

which, together with ln2 ≈ 0.7 is good enough to do a lot of mental arithmetic to one significant figure – three figures if you can think of ln2 ≈ 0.69315 (and this is the type of skill that is dying out all too quickly in the computer age, I think.) Anyway, the lists are terribly intimidating simply because they're so long. Can we maybe coordinate with Oleg somehow to split out the most notable missing articles so that new authors won't feel like they're undertaking a Sysiphean endeavor?

The other practical suggestion I'd make is to just start reading the articles on Wikipedia in areas that interest you. I started working on this stuff less than two months ago. I quickly found that there was practically nothing in Wikipedia about continued fractions with complex elements. Even the fairly prominent articles like complex analysis and complex plane seemed woefully inadequate. I've managed to put quite a bit into the article about the "complex plane", but complex analysis could still benefit from a whole lot more information of a general nature (such as an introduction to analytic continuation, and something about conformal mapping and its applications, etc). It would be good to prioritize the new article lists somehow, but even if that isn't done I bet you can find something good to write about if you just read some of the articles that are already here. DavidCBryant 19:32, 11 January 2007 (UTC)

I do read the articles quite a lot, but I only occasionally run across something I feel qualified enough to write about even with references. I suppose anyone (even I) could write the tiniest of stubs about most topics, but I'd hoped to be able to make a somewhat more substantial contribution. Thus, I was browsing through the missing articles list in search of something I understood.

I think it might be nice if these were categorized, as the requested articles are, since I've never even heard of many of these things. But, there are too many topics listed--we'd never get finished even categorizing them, I suspect. --Sopoforic 20:24, 11 January 2007 (UTC)

Even if they are categorized, it would take forever to create them all. But that's not even the purpose, really. As I view things, that list exists for the following reason: People bump into it, see a redlink, and say "gosh, I know about this". Then people end up writing one or more articles. So, that list is meant to "inspire" I would think, rather than be a to-do list.

In short, I'd suggest you take a look through the lists, see a topic which you feel is important, and which you know about, and write an article about it. On another day, you have nothing to do, then do the same thing. :) Oleg Alexandrov (talk) 04:33, 12 January 2007 (UTC)

Yeah, I get that. I just mean it'd be nice to have them categorized since, for example, I'm not very interested in analysis at all, but I'm pretty interested in combinatorics. So for me, I'd be more likely to bump into an article I could write/would want to write if they were by topic. But, like I said, the effort would surely be disproportionate to the benefit, and not in a good way. (Even the argument I gave seems falsified: I came across Kirkman's schoolgirl problem looking at the list, and it's very interesting indeed, so I made that article. Hopefully this will be a regular occurrence!) --Sopoforic 04:55, 12 January 2007 (UTC)

It may have been mentioned above, but in case it hasn't, the PlanetMath exchange project links are categorized. See Wikipedia:WikiProject_Mathematics/PlanetMath_Exchange if you wanna help out. Lunch 17:46, 12 January 2007 (UTC)

I wouldn't remove something merely because it does not seem notable to me, but maybe I would remove things that seem not notable to me. Michael Hardy 00:14, 13 January 2007 (UTC)

Florentin Smarandache on afd

Hello. I have put Florentin Smarandache on articles for deletion. See: Wikipedia:Articles for deletion/Florentin Smarandache. Please vote. Wile E. Heresiarch 06:18, 14 January 2007 (UTC)

Exponentiation

If anyone is interested, I could use a hand at exponentiation to get the content up to par and resist the efforts of a certain editor to add nonstandard definitions for complex exponentials, roots of unity, etc. CMummert · talk 15:04, 14 January 2007 (UTC)

Commercial / Business Math

I can't find a topic for an important branch of lower mathematics: that which is often called commercial math or business math. It is a practical subject, emphasizing simple arithmetic, percentages, and fractions, but also covering things such as banking transactions (writing checks, for example), purchase orders and invoices, consumer and business loans, etc. All of these things have a mathematical component, or at least a computational one, and they are very widely taught in commercial courses around the world. Does this subject have an article? If not, should it? What should it be called? —The preceding unsigned comment was added by Lou Sander (talk • contribs) 00:30, 14 January 2007 (UTC).

Oops! When I copied this over from elsewhere, I didn't want to include the out-of-date signature. Then I didn't put in a new one. (Another reason ALWAYS to preview.) Sorry. Lou Sander 00:33, 14 January 2007 (UTC)

There's a perfunctory stub on elementary mathematics. It isn't very good, even as stubs go (specifically, it focuses too much on a particular structure of education). Maybe you'd like to expand it, adding a section for business math? --Trovatore 00:49, 14 January 2007 (UTC)

Good idea. Better might be a separate article, though. Whichever way it goes, there needs to be a proper name for the subject. I think of it as "business math" or "commercial math," but those names might be old-fashioned, especially the second one. I teach a course in this stuff, and the famous textbook publisher calls it "college math," which I think is neither appropriate nor descriptive. What on earth do we call this important but pedestrian subject?? Lou Sander 01:08, 14 January 2007 (UTC)

Well, business math might be reasonable as a name for an article about a course (or a "topic" as our English friends, for some odd reason, call it). We have other articles on courses, such as pre-algebra. I guess the question is, if the article is not to be about a course, then what exactly is it about? I don't see that there's any other real unifying theme to the subject matter under discussion. --Trovatore 01:21, 14 January 2007 (UTC)

The unifying theme is its everyday usefulness in commerce. It is what most people think of when they think of "math." ("Most people" being the working classes, etc.) Lou Sander 05:15, 14 January 2007 (UTC)

I suppose that would fall under Elementary mathematics then, but why restrict it to business only? Elementary mathematics would have applications in all kinds of things; cooking, carpentry, sports, business, politics, etc. If you're interested in concentrating just on the business aspect however, you may want to check out the related topics under Business. It sounds like it would fit under the general topic of business as opposed to mathematics. I don't know if there's a talk page similar to this one in the Business subject though. capitalist 07:20, 14 January 2007 (UTC)

EDIT: I looked through the Mathematics Subject Classification briefly but couldn't really find a logical place for "business math". That's why I'm thinking it's more of a business subject than a mathematical one and would be better addressed by that community. capitalist 07:25, 14 January 2007 (UTC)

(Responding to Lou Sander) What I'm saying is that the difference between mathematics used in everyday commerce, and other mathematics, is not inherent to the subject matter; rather, what you seem to be discussing is one particular set of applications of techniques that have non-business applications as well. So you could have an article called applications of mathematics to business or some such, if that's the topic you're trying to get at. But those mathematical topics are not an inherently businessy sort of math, which is why I wouldn't be enthusiastic about lumping them into a business mathematics article. (Though, as I say, a business math article about the course taught under that name would be reasonable. --Trovatore 07:50, 14 January 2007 (UTC)

Update: Wow, business mathematics came up blue -- wasn't expecting that. It seems to be about the course. --Trovatore 07:52, 14 January 2007 (UTC)

Interesting (and thanks for finding it!). I thought I had looked for business mathematics, but I guess not. The present article doesn't now cover the material I'm referring to, but I'll give a shot at adding it. And it's more than just a course... it's what the vast majority of mankind (IMHO) thinks of as "math" -- arithmetic with commercial applications. Believe it or not, they don't even know what trigonometry is. Lou Sander 12:11, 14 January 2007 (UTC)

I added three short paragraphs to business mathematics, thereby (IMHO) plugging a minor hole in our coverage. Lou Sander 13:39, 14 January 2007 (UTC)

No objections to what's there currently. I just want to reiterate the point that we need to keep clear the distinction between "arithmetic with commercial applications" and "commercial applications of arithmetic". The former is not, IMO, an interesting way of categorizing anything; the latter might be. --Trovatore 02:27, 15 January 2007 (UTC)

Precision weighted

I came across this math stub and if anyone at the wikiproject would be interested in cleaning it up a bit. Or I can AFD it if it's not a real thing.Static Universe 19:30, 14 January 2007 (UTC)

It's not a cleanup, it's a complete rewrite, though there is little to rewrite. I speedied it for now as nonsense. Recreation should not be a problem.Circeus 20:13, 14 January 2007 (UTC)

Yeah, I was kind of understating it calling it "cleanup," but thank you. :) Static Universe 02:39, 15 January 2007 (UTC)

Mathematical analysis

The history in the article on mathematical analysis sounds suspect to me. At least it is very different then what I have been taught. I have tried bringing this up on the discussion page, but no were provided. Is anyone, or does anyone know a scholar in the history of mathematics who might take a look at it. I am reluctant to simply remove what is there because I myself can not say for wrong. Thenub314 20:58, 9 January 2007 (UTC)

To which portions of the History section are you referring, in particular? Are you suspicious of the claims made for the "Kerala School" in India? All of the Indian stuff? The "method of exhaustion" (Greece) is solid.

I agree that the bit about India is poorly written. Some of it doesn't even make sense. But I think the claims about actual mathematical discoveries in India are mostly right. The most controversial claim that has been made for the "Kerala School" is that Newton (and/or Leibniz) got his ideas from those guys. But this article doesn't appear to be making that claim. DavidCBryant 21:18, 9 January 2007 (UTC)

I may be correct, it just wasn't able to find any references that supported this point of view. But I should mention that my references are just the 2-3 math history books I own and the the MacTutor mathematics history site. But the fact the MacTutor history site did not claim so much was true, and gave a healthy list of references, togehter with the fact it never came up in my classes in the history of mathematics, made me suspect it. The things that I found particularly strange is the claims about derivatives and Rolle's theorem existing in 12th century india and term by term integration by 14th century. The information about infinite series, continued fraction and trig all seems to be spot on, and is quite amazing. But I just can't find refereed source that supports these claims. Thenub314 14:11, 16 January 2007 (UTC)

I'm trying to add references to the article when I can. If you have references and want to rewrite the paragraph about mathematics in India by all means go ahead and do so. I'm not certain that every bit of Indian historical information in the article is accurate ... I just said it's "mostly right". So if you think the bit about derivatives, and integration, is not quite accurate, blow it out of there. Or write me something on my talk page citing the references you've looked at, and I'll take a stab at that one paragraph. DavidCBryant 14:44, 16 January 2007 (UTC)

Computing Pi

This article seems problematic to me. It might be in violation of the rule against how-tos. AfD, or can it be improved, or merged somewhere? --Trovatore 06:25, 13 January 2007 (UTC)

I'm surprised to find that there isn't a natural merge target. Pi#Efficient methods seems to be the current home for such information; much of it should probably be merged away from that long main article. Melchoir 07:06, 13 January 2007 (UTC)

This topic is already well covered by our article on π, by our history of numerical approximations of π, and elsewhere. Since this stub is spotty, poorly written, and under the wrong title ("Pi" should not be capitalized), I'd say PROD, and AfD if necessary. (I see no point in a re-organization discussion unless a competent champion volunteers to do the work.) --KSmrq^T 07:23, 13 January 2007 (UTC)

Huh, I didn't notice it before, but that History of numerical approximations of π article has a lot of verbatim overlap with Pi#Efficient methods. That's a Bad Thing; surely someone can fix it? Melchoir 07:32, 13 January 2007 (UTC)

I agree that Computing Pi is not worth keeping on Wikipedia. I'm curious about the "rule against how-tos", though. I don't think I've run across that one yet ... would someone please point me to it? ("It's not that I want to break the rules," said Alice. "If only there weren't so many of them.") DavidCBryant 18:54, 13 January 2007 (UTC)

That would be WP:NOT#IINFO, under instruction manuals. Melchoir 19:18, 13 January 2007 (UTC)

A redirect to History of numerical approximations of π is a lot simpler than an AfD. By itself Methods for computing pi is a notable topic, and it is hard to maintain that the article is a how-to style manual.  --Lambiam^Talk 19:41, 13 January 2007 (UTC)

I think the redirect is a good idea. Oleg Alexandrov (talk) 19:56, 13 January 2007 (UTC)

Sure, I'd accept a redirect. And again, "someone can fix" anything on Wikipedia; I'm not keen on mythical beings.

The claim that any of these items constitutes a "how-to" manual and somehow breaks a "rule", like WP:NOT#IINFO, is debatable. Wikipedia has vast numbers of editors, and a correspondingly vast spread of opinions of what it is or should be. Take any opinion (including mine) as a thought to consider, not a commandment from God, unless it comes from Jimmy Wales. In the long run, common sense and consensus, trained by experience, are your best guide. In my opinion. ;-) --KSmrq^T 05:02, 14 January 2007 (UTC)

I don't think computing π needs to be a how-to. It could include how-to stuff but also theretical stuff about computation of π. For example, if there's a theorem that says no algorithm can comute the π to within ε faster than thus-and-so, it could be included.

I think it's a worthy topic, and although the present form of the article is clumsy, it could be brought up to reasonable standards.

I've fixed the title; it's now the Greek letter and not the upper-case "P". Michael Hardy 02:22, 15 January 2007 (UTC)

Are you suggesting we need both articles, History of numerical approximations of π – which has a section Development of efficient formulae – and Computing π? There is a huge overlap. I think one article covering the history as well as current efficient methods should be enough. Size is currently not an issue.  --Lambiam^Talk 11:22, 15 January 2007 (UTC)

Postscriptum. There is also Software for calculating π, Machin-like formula and List of formulae involving π#Efficient infinite series.  --Lambiam^Talk 11:34, 15 January 2007 (UTC)

The idea was not to make a how to(I'm sorry if it seems that way), it was to organise all the forumlas on the main Pi page . As it is, they are spread through-out the page. I find the "Calculating pi" section to be much cleaner now. The formulae section is large and alot to sift through right now. In my opinion the most important sections (Geometry, Physics,...) should be preserved and the rest (Analysis, Miscellaneous formulæ, ...) moved to appropriate pages (computing π, List_of_formulae_involving_π). Deathbob 02:15, 16 January 2007 (UTC)

Smarandache-Wellin number

I put Smarandache-Wellin number up for deletion; AfD discussion is here. —David Eppstein 20:59, 15 January 2007 (UTC)

Misner space

Could someone have a look at this? The article's derived from a popularization, and I'm not even sure this is an exact solution to GR or a piece of topology. Septentrionalis PMAnderson 23:11, 17 January 2007 (UTC)

I've trimmed it right down to something minimally verifiable: can someone who knows something about this expand it? -- The Anome 02:20, 18 January 2007 (UTC)

Is it really a good idea to take all that stuff out? It made some (little) sense before. Now it is a total mystery. JRSpriggs 08:18, 18 January 2007 (UTC)

Margin of error FAR

Margin of error has been nominated for a featured article review. Articles are typically reviewed for two weeks. Please leave your comments and help us to return the article to featured quality. If concerns are not addressed during the review period, articles are moved onto the Featured Article Removal Candidates list for a further period, where editors may declare "Keep" or "Remove" the article from featured status. The instructions for the review process are here. Reviewers' concerns are here. Kaldari 06:16, 18 January 2007 (UTC)

Odd bug in <math> processor.

Yesterday I was entering a formula that involved the expression z to the (2 to the n) power. I got a very odd result ... the <math> processor did not return an error (big red "failed to parse"), but the graphics engine that converts <math> to png images wouldn't work, or something, so that all I saw on a "show preview" was the raw TeX code, without the <math></math> tags around it. Oh – it also knocked the graphics interface out of commission entirely, not just on the line where I had the stacked superscripts, but throughout the rest of the page, as well. (I was using Firefox under Linux when this happened).

I finally figured out what the problem was by firing up my other browser, Konqueror, which rendered the other formulas OK, but failed on the one line that included z to the (2 to the n) power. That's why I suspect the graphics engine (it sort of gave up under Firefox, but Konqueror got a better result).

Anyway, I have a few questions. Is there a better place to report this problem? Some sort of technical support group, or something? And is there a central repository of information about bugs in wiki-TeX, where newcomers can learn about this sort of thing without having to hack through it on their own? Thanks! DavidCBryant 15:01, 18 January 2007 (UTC)

We have bugzilla for reporting bugs. They should be filed under 'mediawiki extensions.' --Sopoforic 17:06, 18 January 2007 (UTC)

The HTML "ALT" text for math images is the raw TeX code; you can look at it in Firefox by selecting "Properties" when right-clicking on a math image like this one $z^{2^{n}}\$. Maybe your browser just hadn't loaded the math PNGs and so was displaying the ALT text. Do you have a reproducible example of the bug? CMummert · talk 17:17, 18 January 2007 (UTC)

I can see the image just fine in your message, CMummert. I'll go back to the article I was working on and see if I can reproduce the problem. I don't generally right-click on images, but now that I've looked more closely I see that I've got an option "block images from wikimedia..." I suppose that I might have selected that option inadvertently. Maybe it was load-related ... as I mentioned, Konqueror got most of the images, just not the one image with $z^{2^{n}}$ in it. Sometimes when I run a search on Wikipedia it tells me to use Google or Yahoo instead. I guess that happens when the servers are under stress. Could there be something in the network OS that limits the generation of images when CPU cycles are getting scarce? That image generation process has got to be computationally expensive. Anyway, thanks for the feedback, both of you. DavidCBryant 19:13, 18 January 2007 (UTC)

I've been seeing a lot of random image loading failures lately, which especially impacts PNGs from <math> markup. These should (almost) all be cached, so I don't know where the failure is; I assume it is a server hiccup of some sort. --KSmrq^T 22:45, 18 January 2007 (UTC)

This is a known bug; refresh and it'll work fine. IIRC it is something to do with NFS and access times. — Preceding unsigned comment added by 58.163.151.30 (talk • contribs)

Opposite (mathematics)

The page Opposite (mathematics) might need some attention from any mathematicians. It was found in Special:Ancientpages, and could probably be turned into a redirect, or even deleted. --Montchav 16:53, 8 January 2007 (UTC)

I merged it into opposite. - grubber 05:52, 21 January 2007 (UTC)

A few polygons for deletion

I've nominated Hectagon, Pentacontagon, and Tetracontagon for deletion since Decemyriagon was deleted. You can find the discussion here. --Sopoforic 02:25, 22 January 2007 (UTC)

Merging Ramanujan summation?

It looks like Ramanujan summation and Ramanujan's sum are about the same, or very closely related, topics. Should they be merged? -- The Anome 12:55, 22 January 2007 (UTC)

I don't see the connection. The first article refers to a method of assigning a value to divergent series – that's probably something like Cesaro summation, although the article doesn't explain it very well. Is this one of those "Ramanujan mysteries", where people think anything he wrote down has to be important, but nobody else has figured it out yet?

The second article describes finite sums which cannot possibly diverge. DavidCBryant 14:35, 22 January 2007 (UTC)

I don't see how you could possibly merge them; the topics are not remotely similar. Michael Hardy 22:44, 23 January 2007 (UTC)

Triangle

I am having an argument with an anon at Triangle about what should be included in that article and what not. Comments would be welcome at Talk:Triangle#What should be included. Oleg Alexandrov (talk) 03:17, 24 January 2007 (UTC)

Set at AID

The article Set is up for nomination at the Article Improvement Drive. It's such a core topic in Mathematics that I'm surprised it's not at GA status already. CloudNine 14:46, 21 January 2007 (UTC)

Its nomination certainly has my support. Iotha 18:11, 24 January 2007 (UTC)

A couple of questions

I'm working on a couple of articles for mathematical problems, and I'd like some opinions on a couple of issues. First, I'm not quite sure what I should do when stating the problems. They're old enough that I can quote the original statement of the problem. Assuming that the original statement is clear enough, would it be a good idea to quote it directly, rather than trying to come up with my own wording? Second, regarding solutions: in Kirkman's schoolgirl problem, I've got a copy of an arrangement that solves the problem. Would the article benefit from listing this solution? It doesn't really add anything, from a mathematical standpoint (except proving that there is a solution, I guess), but perhaps a reader would be interested in it. I do intend to add more information to it once I get a few things via ILL, but should I add the solution in the meantime? --Sopoforic 23:37, 23 January 2007 (UTC)

It's a nice article, Sopoforic. I think examples and solutions are good to have. How long is the solution? If it's not too long, I'd add it. Oh – are you sure you want all those red links? I don't suppose there's any real rule about it, but I usually try to introduce no more than one red link in a new article, and then only if I intend to write the red-linked article fairly soon. DavidCBryant 23:59, 23 January 2007 (UTC)

IIRC, the style guide says to put redlinks whenever it'd be useful to have that information linked, and when it is probably possible to write an article on that topic. I'm thinking of writing up one or two of those, and it doesn't really hurt to leave them. But I should probably de-link the title of Ball's book in the refs.

The length of the solution? Well, an arrangement that solves it is just seven sets of 35 characters, so it's not much. The solutions that I have that explain how to arrive at this (or, better, proving how many different solutions are possible and things like that) are quite a bit longer. Ball's book gives a solution in a couple of pages which I can probably summarize and include.

I was really more concerned with the first part. I've written up a bit on Archimedes' cattle problem at User:Sopoforic/Sandbox, which I'm planning on copying into the article space once I've got a bit more added to it, but I'm not sure how I should state the problem. If you'd give your opinion on that, I'd be most grateful. --Sopoforic 01:14, 24 January 2007 (UTC)

A bit more info on this: I'm pretty sure I've found an English translation (out-of-copyright) of the 22 couplets that make up the statement of the cattle problem. It seems to me that it'd be nice to include this in the article, but what I've got written now is surely clearer in terms of the mathematical meaning of the problem. Further, a 44-line poem may make the article a bit long for small gain. Should it be added to the article? Or perhaps this is a time when wikisource should be used. I'm not really sure. Comments are welcome. --Sopoforic 01:53, 24 January 2007 (UTC)

I would add the solution to Kirkman's problem, as an aid to the reader; Archimedes' poem belongs in Wikisource (and a prose version might be better, unless the couplets are more accurate than usual for verse translations.) Septentrionalis PMAnderson 19:36, 24 January 2007 (UTC)

Giving credit for articles translated from the Wikipedia's of other languages

I translated Halley's method from French to English. My source was fr:Itération de Halley. So I just informally put a link to it in the article, saying "*[[:fr:Itération de Halley]], French original". The original author Lachaume (talk · contribs), asked me (at User talk:JRSpriggs#Halley's method) whether I should not be using a template. Is there a template for giving credit to sources on other Wikipedias? JRSpriggs 07:00, 25 January 2007 (UTC)

I don't think that there is such a template. Wikipedia:Translation/*/How-to has a template, but I think that it's meant for coordinating a translation effort, rather than giving credit. --Sopoforic 07:50, 25 January 2007 (UTC)

There are the templates Template:German, Template:Italian, Template:Polish, and so on, but it seems there is no template for French yet. Go figure. (NB: Template:French redirects to a navbox template.) See Category:Interwiki link templates or Category:Citation templates. Lunch 07:53, 25 January 2007 (UTC)

I didn't know of any template, but I think probably there should be a little more detail than just an interwiki link. At Prime minister of Italy I put a note in the References section pointing to the version I translated and stating the date it was retrieved. --Trovatore 07:54, 25 January 2007 (UTC)

Thanks. I will change it to follow your model, Trovatore. JRSpriggs 12:00, 25 January 2007 (UTC)

Articles listed at Articles for deletion

• List of formulae involving π (AfD discussion)
• List of physics formulae (AfD discussion) (see also Physics equations (AfD discussion))

Uncle G 12:02, 25 January 2007 (UTC)

Elementary mathematics

I think we really need some cleanup to be done on our articles on elementary mathematics. We put so much work into the articles on more obscure areas of mathematics, leaving our basic articles, the ones which are probably most viewed, neglected. Just by going to five random articles on elementary topics, I've basically either redone the opening paragraph or done serious work to all of them, as they were incomplete, incoherent, or misleading (see [1], [2], [3], [4], and [5]). —Mets501 (talk) 03:08, 25 January 2007 (UTC)

It's good that you are interested in editing these articles. For some reason, the more elementary articles tend to be the ones that lead to the most contentious editing. That may be why others stay away from them. CMummert · talk 03:25, 25 January 2007 (UTC)

I suspect it's due to the elementary articles being the most likely to be edited by a non-math person, or by a math person who has not yet gone into many of the advanced topics, which can lead to contentious editing (such as whether a trapezoid has only one set of parallel sides or at least one set. --Carl ^{(talk|contribs)} 14:47, 25 January 2007 (UTC)

Yes, most likely. They are also the most vandalized and edited, so it is harder to keep them stable. —Mets501 (talk) 14:57, 25 January 2007 (UTC)

Amen. I, too, had the experience of writing what I thought was a nice article on an introductory topic, which was promptly blanked by a clueless kid. I view the difficulty of editing and patrolling such articles as one of the more discouraging aspects of WP. This is why I've tried to follow the various proposals and efforts at defining "stable versions" and the accompanying editorial oversight boards.linas 05:50, 26 January 2007 (UTC)

I approach elementary articles timidly because they are difficult to write well. When I edit a more advanced article, I can use a sentence or two to orient the general reader and warn them off, then get down to business for the hard-core "mathematically sophisticated" reader. So-called "elementary topics" often aren't. What I mean is that they may first be met in early years, but a full treatment can draw on demanding foundations and lead to more sophisticated areas. Consider counting. This is something very young children learn and enjoy, but a full mathematical discussion should include the Peano axioms — a university-level topic, and might also consider the natural number object of category theory — a doctorate-level topic. It is already challenging to write well for young readers only, and considerably more difficult to write for graduate students at the same time!

And, as other have observed, since everyone "knows" (more correctly, thinks so!) about an "elementary" topic, everyone feels free to "improve" (actually, disrupt) the article. Primitive readers mess up the advanced delicacies, and advanced readers often lack sensitivity for young readers. Ah, the joys of Wikipedia! --KSmrq^T 05:59, 26 January 2007 (UTC)

series field in {{cite book}}

There is now a "series" field in the {{cite book}} template, as the following example illustrates. CMummert · talk 03:52, 26 January 2007 (UTC)

Mumford, David (1999). The Red Book of Varieties and Schemes. Lecture Notes in Mathematics 1358. Springer-Verlag. doi:10.1007/b62130. ISBN 354063293X.

{{cite book | last = Mumford | first = David | authorlink = David Mumford | title = The Red Book of Varieties and Schemes | publisher = [[Springer-Verlag]] | series = Lecture Notes in Mathematics 1358 | year = 1999 | doi = 10.1007/b62130 | isbn = 354063293X }}

This is good news. I cite a lot of books with {{cite conference}} but I think {{cite book}} would work for most of them and this gives a good reason to switch. Thanks! —David Eppstein 05:01, 26 January 2007 (UTC)

Notice by the way the very nice tool available at http://diberri.dyndns.org/wikipedia/templates/ which can generate book templates. Oleg Alexandrov (talk) 05:49, 26 January 2007 (UTC)

Zariski surfaces

Due to the recent banning of Dr. Piotr Blass, I have put his primary contribution to mathematics, the Zariski surface up for deletion as its sources are questionable, and the contributions made by Dr. Blass to the page also have some issues. Seeing as barely anyone knows what a Zariski surface is, I am bringing it to attention here to try and see what should be done.—Ryūlóng (竜龍) 01:51, 18 January 2007 (UTC)

ROFL we edit conflicted while I was composing my own version of this request. Yes, the creator and main contributor to this article has been sitebanned for persistent vanity and disruption. Dr. Blass claims to have named the concept of a Zariski surface and we non-mathematicians would would appreciate if specialists weighed in about whether this page meets site standards for retention. Respectfully, Durova^Charge 01:55, 18 January 2007 (UTC)

Piotr Blass does not appear to be the initial auther of the article, from the edit history. Richard Borcherds does so appear. Michael Hardy 01:05, 21 January 2007 (UTC)

It would be nonsense to delete it. At most it should be semi-protected. Charles Matthews 12:19, 22 January 2007 (UTC)

Piotr Blass is now on Wikipedia:Deletion review/Log/2007 January 24, with a new draft article. --Salix alba (talk) 23:25, 24 January 2007 (UTC)

AfD again. --Salix alba (talk) 08:36, 25 January 2007 (UTC)

Hi, I've started a basic fact dump for the "Ulam Quarterly" journal. As yet, I dont have an opinion on whether the journal would satisfy our notability criteria, but would appreciate any input by academics in the field. John Vandenberg 05:03, 27 January 2007 (UTC)

Something is odd with the categories system

I noticed something odd with the categories system. Take for example the article Maximum modulus principle. It is categorized in Category:Complex analysis as expected. However, if you actually visit that category, the article is just not there. Same for Argument principle, Antiderivative (complex analysis), etc., which are categorized in Category:Complex analysis but don't show up in the category itself. Anybody else noticing the same thing? Oleg Alexandrov (talk) 05:49, 26 January 2007 (UTC)

Seems to be some caching problem. I edited Maximum modulus principle, hacked on the cat, reverted myself, and now it shows up. linas 06:00, 26 January 2007 (UTC)

I've seen the same problem for the last week or so with Category:Graph products. It's only showing two articles, but there are several others with that category that are not shown. —David Eppstein 06:04, 26 January 2007 (UTC)

See also /Archive 21#A bug?. And I also had the problem with another file, but it went away when I moved an improperly located inter-wiki link down after the category. It seems to go away when you edit the file. JRSpriggs 07:25, 26 January 2007 (UTC)

It looks like saving the articles caused the category links to be updated. Saving the category did not seem to do the trick I looked at bugzilla briefly but didn't see anything. CMummert · talk 13:56, 26 January 2007 (UTC)

The articles that should be in Category:Graph products are: Cartesian product of graphs - Hedetniemi's conjecture - Lexicographic product of graphs - List of mathematics categories - Rooted product of graphs - Vizing's conjecture . Hmm. CMummert · talk 14:04, 26 January 2007 (UTC)

I reported it as a bug on bugzilla. CMummert · talk 14:10, 26 January 2007 (UTC)

Thanks! That's great! Oleg Alexandrov (talk) 03:32, 27 January 2007 (UTC)

The whole category system is vastly inferior in virtually all respects to the system of topics lists. Michael Hardy 21:07, 26 January 2007 (UTC)

I would disagree in the strongest terms. :) Categories are "bottom up" approaches, where each article is categorized independently of other articles, and a list of all categorized articles is automatically generated. "Bottom up" approaches work much better on Wikipedia than top-down approaches, like creating a list, where you need an expert to regularly and go through tons of articles and add list them in the appropriate list (that almost never happens, and this approach can't scale for millions of articles).

OK, lists and categories are actually complementary. Luckily we are not forced to choose between one or the other. Oleg Alexandrov (talk) 03:32, 27 January 2007 (UTC)

product rule

Maybe some of the really elementary articles should be on the watchlists of more mathematicians. Some idiot added to product rule a proposed "alternate proof". Those parts of the "alternate proof" that were valid were no different from the proof that was already there. But after saying f(x) = u(x)v(x) the "alternate proof" section said:

By hypothesis, $f'(x)=u(x)v'(x)+u'(x)v(x),\,$

and went on to rely substantially on that "hypothesis". I deleted it, and rebuked its author rather harshly---I imagine someone's going to accuse me of violating the "assume good faith" rule, but I think anyone who adds what purports to be a mathematical proof to an article should understand that which is secondary-school pupils are expected to learn about what proofs are. Michael Hardy 21:07, 26 January 2007 (UTC)

logarithm

In logarithm, I wrote:

The quantity log_b(x) is a function of both b and x, but the term "logarithmic function" in standard usage refers to log_b(x) as a function of x while b is fixed. Thus there is one logarithmic function for each value of the base b (which must be positive and must differ from 1).

Viewed in this way, the base-b logarithmic function is the inverse function of the base-b exponential function.

At talk:logarithm someone is disputing this and thinks my impression of what a logarithmic function is must have come from one book which I failed to identify. Perhaps others here can talk some sense into him (or into me, if need be). Michael Hardy 23:55, 26 January 2007 (UTC)

I am not disputing that statement. It is correct. Please see the Talk:Logarithm. —Mets501 (talk) 03:46, 27 January 2007 (UTC)

Most wanted redlinks

While updating User:Mathbot/List of mathematical redlinks, I made a list of redlinks which show up more than once in math articles. It is available at User:Mathbot/Most wanted redlinks (sorted by number of times each link occurs). Some of those might be worth filling in. Oleg Alexandrov (talk) 00:17, 28 January 2007 (UTC)

Nice. I was going to suggest something like this sometime :-) --C S (Talk) 01:20, 28 January 2007 (UTC)

BTW, I've had occasion to bump into editors who don't seem to realize red links are important. I left some comments to this effect at the talk page for Wikipedia: Red link. Perhaps somebody can help out with cleaning up that page. At the moment, some of the things are kind of confusing. For example, while a careful reading shows that red links are useful and should not be blindly removed, some people apparently read the part that explains that broken red links (ie. those leading to deleted pages or misspellings) should be removed and think that means all red links are broken.

Since WikiProject Mathematics uses red links in such a crucial systematic fashion, I think it would be good to modify that guideline (or whatever it is...) to mention this kind of use by WikiProjects. --C S (Talk) 01:25, 28 January 2007 (UTC)

Quadratic disambiguation

Formerly, Quadratic redirected to quadratic equation.

This was inappropriate in many of the contexts that linked to it. For example, Gyro monorail has "the stability quartic must be factorised into a pair of quadratic terms"; John Muth contains "Herb Simon had shown that with quadratic costs...", and algebraic function has "of a parabola, a quadratic algebraic function in x". The quadratic equation is not relevant to any of these.

I have made a disambiguation page at quadratic. But because there are many different, albeit related uses of "quadratic", it would probably be better if the links to the quadratic article were changed to link to more specific meanings: quadratic function, quadratic polynomial, or whatever.

-- Dominus 17:38, 28 January 2007 (UTC)

I've categorized the various kinds, as the list was a bit long. Also, I removed some of the entries, as some were redirects to things already in the list. Check it out and see if I have categorized them appropriately. - grubber 23:23, 28 January 2007 (UTC)

I just fixed a few of the links to quadratic ... it was fun. From the quadratic page I just hit "What links here" in the "toolbox" and started working through the list. Today I learned, for instance, that the Brits call vacuum tubes "valves". Fascinating! Oh – it just occurred to me. Isn't "quadratic disambiguation" when a dab page points to another dab page? Is there a rule against that?  ;^> DavidCBryant 13:01, 29 January 2007 (UTC)

Americans called them "valves" also, long ago. It's because they allow current to pass through in one direction, but not in the other. -- Dominus 21:03, 29 January 2007 (UTC)

That kind of work can be very satisfying sometimes. A while back I went around and disambiguated all the links to Red Hook. Most of them were actually referring to Red Hook, Brooklyn, but not all. I found out that H.P. Lovecraft lived in Red Hook, Brooklyn. What a surprise! -- Dominus 21:06, 29 January 2007 (UTC)

Is there a rule against a disambiguation page pointing to another disambiguation page? Not that I know of. I have seen it once or twice. Some words are used for so many different things that you need to have an overall disambiguation page with many entries and one of them points to another disambiguation page which separates the mathematical usages. JRSpriggs 08:07, 30 January 2007 (UTC)

This is odd. I was working through "What links here" when I ran across this dab page, which points to this dab page. It's self-referential (that is, quadratic itself is an example of second-order disambiguation). Did somebody do that on purpose?  ;^> DavidCBryant 11:26, 30 January 2007 (UTC)

Good job all, the nicest disambig page I've seen in a long while. --Salix alba (talk) 08:55, 30 January 2007 (UTC)