The following discussion is an archived debate of the proposed deletion of the article below. Please do not modify it. Subsequent comments should be made on the appropriate discussion page (such as the article's talk page or in a deletion review). No further edits should be made to this page.

The result was delete. MuZemike 20:37, 19 November 2009 (UTC)[reply]

List of nascent delta functions[edit]

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WP:CFORK/WP:POVFORK of Dirac delta function. Refer to the longstanding thread Talk:Dirac delta function#Explanation of table removal. First of all, this content was never removed from the article: rather an unorganized list was incorporated into the existing article in a way that gave context to the entries of the table as mere examples of various much more general phenomena. Secondly, the new article includes a paragraph that has already been thoroughly refuted at Talk:Dirac delta function as an overly complicated way of expressing a simple general phenomenon. Thirdly, some of these only approximate the delta function in measure, whereas others do as a distribution, but no attempt is made to distinguish between these two cases (in contrast to the main article, where such a distinction is made clear). Fourthly, it is a hopeless task to attempt to list all nascent delta functions—even all of those that are in some sense "notable" as appearing in the literature (a point which, at any rate, is moot since main part of the article is entirely unreferenced). Le Docteur (talk) 15:41, 4 November 2009 (UTC)[reply]

1. I agree that the content is in Dirac delta function, and explained in a way that makes it easier to see why these particular examples of nascent delta functions are useful. But I have found myself on several occasions looking for the definition I need (to check the normalization, and to make sure that my definition is conventional) and having to scroll through several paragraphs to find the right one. Surely a list is the appropriate way to collect this information for easy reference.

2. and 3. There are certainly faults with this article, but I don't see that these are arguments for deleting it.

4. You could equally make this point about the article List of integrals of rational functions. Lists can be useful, even if they aren't (or can't in principle be) comprehensive.

Stevvers (talk) 15:55, 5 November 2009 (UTC)[reply]

I will just comment on point 4. List of integrals of rational functions should be completely rewritten and moved to integration of rational functions. It is not really a list, but rather a somewhat inverted description of the algorithm for integrating rational functions. This, of course, is pure WP:OTHERSTUFFEXISTS, but it is an excellent example of another "list" that would be better off as (part of) an article. Le Docteur (talk) 12:40, 12 November 2009 (UTC)[reply]

Delete. Regardless of the fact that it's a fork (not necessarily a WP:CFORK) of Dirac delta function, and the history supplied by the nominator, the article doesn't stand on it's own. For (almost) any probability density function $\varphi$ ,

\delta _{a}(x)={\frac {1}{a))\varphi \left({\frac {x}{a))\right)

is a "nascent delta function". That pretty much takes care of the list. — Arthur Rubin (talk) 16:00, 4 November 2009 (UTC)[reply]

Delete Unnecessary fork. Put a redirect to Dirac delta function following deletion. Ray^Talk 20:31, 4 November 2009 (UTC)[reply]
Delete – unsupported content fork. Dicklyon (talk) 07:22, 5 November 2009 (UTC)[reply]
Comment Arthur Rubin is saying this works for almost any probability density function. But it possible that there are a few for which it is persistently useful to do this, whereas for most it is not? Michael Hardy (talk) 17:20, 6 November 2009 (UTC)[reply]
- It will be less useful to do this for bimodal distributions. But in practice they are the minority. Septentrionalis PMAnderson 19:53, 6 November 2009 (UTC)[reply]

Note: This discussion has been mentioned at Wikipedia talk:WikiProject Physics#List of nascent delta functions on AfD. - 2/0 (cont.) 20:27, 6 November 2009 (UTC)[reply]

...and also at Wikipedia_talk:WikiProject_Mathematics#List_of_nascent_delta_functions_on_AfD. Michael Hardy (talk) 03:42, 7 November 2009 (UTC)[reply]

Well let me be the first to say keep and expand. The list is an extremely neat summary of commonly-used distributions used to visualize and study the dirac delta and its derivatives. The fork argument is not valid imo, this list has a different purpose than the article and having some duplication of content is not evil. Headbomb {^ταλκ_{κοντριβς} – WP Physics} 17:25, 10 November 2009 (UTC)[reply]

Comment. Useful content on how to "visualize and study the dirac delta and its derivatives" should clearly be in the main article rather than here. To expand on some of the above objections, there are essentially three ways that nascent delta functions come up in practice: (1) as fundamental solutions of differential equations, (2) by a rescaling of a probability distribution or mollifier, or (3) by a limit of a Fourier transform (what the main article calls an oscillatory integral). Within each of these respective domains, there is an enormous variety of possibilities that are all fairly similar when it gets down to brass tacks. Rather than have an indiscriminate table of nascent delta functions (some of which, by the way, are not even all that common), it would probably be better to have a few choice examples in the main article that illustrate the general principle. Let me add that if this list is to survive the AfD, then given the enormous number of possibilities of nascent delta functions that have appeared in the literature, this should limit itself to content that is not only sourced, but also for which there is an existing Wikipedia article (compare List of numbers, List of mathematical functions, List of matrices). Le Docteur (talk) 12:33, 12 November 2009 (UTC)[reply]

Relisted to generate a more thorough discussion so consensus may be reached.
Please add new comments below this notice. Thanks, Cunard (talk) 05:55, 12 November 2009 (UTC)[reply]

Relisting comment: I have relisted this AfD debate to generate discussion about Headbomb (talk · contribs)'s "keep" comment. Cunard (talk) 05:55, 12 November 2009 (UTC)[reply]

The above discussion is preserved as an archive of the debate. Please do not modify it. Subsequent comments should be made on the appropriate discussion page (such as the article's talk page or in a deletion review). No further edits should be made to this page.