Path: news.mathworks.com!not-for-mail 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) Lines: 19 Message-ID: <is0fhc$lps$1@newscl01ah.mathworks.com> References: <is0cmq$fbf$1@newscl01ah.mathworks.com> Reply-To: "John D'Errico" <woodchips@rochester.rr.com> NNTP-Posting-Host: www-03-blr.mathworks.com Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Trace: newscl01ah.mathworks.com 1306771820 22332 172.30.248.48 (30 May 2011 16:10:20 GMT) X-Complaints-To: news@mathworks.com NNTP-Posting-Date: Mon, 30 May 2011 16:10:20 +0000 (UTC) X-Newsreader: MATLAB Central Newsreader 869215 Xref: news.mathworks.com comp.soft-sys.matlab:729312 "Tomer Alon" <tomeralon112@gmail.com> wrote in message <is0cmq$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