Talk:Support (mathematics)

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References needed. Geometry guy 20:45, 31 May 2007 (UTC)

In case I bugger it up, the union of the support and the kernel of a numerical function make up the domain of that function, correct? Dysprosia 10:12, 17 Jul 2004 (UTC)

Hello I am confused by the statement in "Support": " Singular supports may also be used to understand phenomena special to distribution theory, such as attempts to 'multiply' distributions (squaring the Dirac delta function fails - essentially because the singular supports of two distributions to multiply should be disjoint)." Seems to me if you multiply two distributions whose support is disjoint, you will get zero. Is that not true? Seems to me that the problem in squaring a Dirac Delta has more to do with orders of infinity and limiting processes. Thanks Peter Pdn Feb 20, 2005 4:22 PM EST or 9:22 PM UTC I suppose

But the singular support is not the support. Charles Matthews 22:11, 20 Feb 2005 (UTC)

The "sing supp" is the support w.r.t. the subsheaf C^∞ while "supp" is the support w.r.t. the subsheaf {0}. At least some links to sheaf seem necessary to me. MFH 02:14, 12 Mar 2005 (UTC)

Can the concept of support be applied to geometry? I think that would make a good graphical example for newcomers to the idea, if so. The intro is a little hard to parse — Omegatron 20:17, 19 October 2005 (UTC)

I'm doing some groundwork for expanding the GJK page. One of the core features of the algorithm is that it only relies on the support function for a specific geometric shape, which is a definition I'm not seeing on this page. Mathematically, this function should take in a vector V and return the point on the surface of the geometry that results in the largest value when you dot V with every point on the geometry's surface.

As examples: the support function of a sphere would always return normal(V) * radius; the support function of a box would always return one of the eight box vertices; the support function of a capsule/sphyl would always be a point on one of the two endcaps.

In this context, I believe the support function for non-convex shapes is undefined. Does anyone with a stronger math background than me want to confirm or correct any of this stuff, or point out which article it belongs in? I'd like to make sure that I correctly link the GJK article there for the relevant information. --Kyle Davis 18:40, 29 November 2005 (UTC)

1 help
2 qua! qua!
3 Support of a probability distribution
4 Explanation?

[edit] help

I clicked this page thinking it was were I could get some SUPPORT for a math question!

[edit] qua! qua!

While this is clearly a special point, it is more precise to say that the transform qua distribution has singular support {0} [...]

Qua? --Abdull 04:41, 13 June 2006 (UTC)

[edit] Support of a probability distribution

I don't like this sentence: "In particular, in probability theory, the support of a probability distribution is the closure of the set of possible values of a random variable having that distribution." In probability distribution it is defined better: "The support of a distribution is the smallest closed set whose complement has probability zero." --130.94.162.64 00:57, 21 June 2006 (UTC)

To add one more thing:

A point x is said to belong to the support of a distribution function F if for every $\epsilon\ > 0$ , we have:

$F(x + \epsilon\ ) + F(x - \epsilon\ ) > 0$ . —The preceding unsigned comment was added by Musically ut (talk • contribs) 13:10, 4 February 2007 (UTC).

[edit] Explanation?

I've taken some analysis, but can't follow this article. It opens

In mathematics, the support of a real-valued function f on a set X is sometimes defined as the subset of X on which f is nonzero. The most common situation occurs when X is a topological space (such as the real line) and f is a continuous function.

Staying with real-valued functions (e.g., f:R→R) it isn't clear to me if X is a set of real numbers, of real-valued functions, or what. That is, is this saying that the support, S, is defined as

$S = \{ x \in X | f(x) \neq 0 \}$