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From: "John D'Errico" <woodchips@rochester.rr.com>
Newsgroups: comp.soft-sys.matlab
Subject: Re: 2-d numerical integration
Date: Mon, 30 May 2011 16:10:20 +0000 (UTC)
Organization: John D'Errico (1-3LEW5R)
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"Tomer Alon" <tomeralon112@gmail.com> wrote in message <is0cmq$fbf$1@newscl01ah.mathworks.com>...
> hi, i have a question about 2-d integral.
> i have a matrix for x,y,data and i can't express my data as a function.
> how can i do an integral on the data with respect to the x,y points?
> thanks for the helpers

You cannot integrate points. Points, shmoints. Well,
you can integrate over them, but it is a set of measure
zero, so a rather boring result.

You can integrate a function. So you need to define
a domain. You need to find a function that approximates
or interpolates those points. Then integrate that function
over the indicated domain. This may involve a triangulation
of the domain from these points. If the domain is not
convex, then the triangulation will be more difficult.

HTH,
John