Path: news.mathworks.com!not-for-mail From: "hyun doo ahn" <hjlovme@hotmail.com> Newsgroups: comp.soft-sys.matlab Subject: Re: circular plate 3D plot Date: Mon, 3 May 2010 18:52:26 +0000 (UTC) Organization: The MathWorks, Inc. Lines: 27 Message-ID: <hrn61a$6fn$1@fred.mathworks.com> References: <hrmr2n$sij$1@fred.mathworks.com> <hrn0fc$s6m$1@fred.mathworks.com> Reply-To: "hyun doo ahn" <hjlovme@hotmail.com> NNTP-Posting-Host: webapp-02-blr.mathworks.com Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Trace: fred.mathworks.com 1272912746 6647 172.30.248.37 (3 May 2010 18:52:26 GMT) X-Complaints-To: news@mathworks.com NNTP-Posting-Date: Mon, 3 May 2010 18:52:26 +0000 (UTC) X-Newsreader: MATLAB Central Newsreader 2338760 Xref: news.mathworks.com comp.soft-sys.matlab:632102 "Roger Stafford" <ellieandrogerxyzzy@mindspring.com.invalid> wrote in message <hrn0fc$s6m$1@fred.mathworks.com>... > "hyun doo ahn" <hjlovme@hotmail.com> wrote in message <hrmr2n$sij$1@fred.mathworks.com>... > > Dear all > > I know how to make 2d circle plot by polar function > > I have a question to make a circular plate 3D without polar3d > > ....... > > As you have stated the problem you have a circular ring, not a "plate", in the x-y plane. To make this a solid disk which would be appropriate for using 'surf' you need to have a mesh containing both a varying theta and a varying radius. Perhaps you mean to do something like the following. > > radius = linspace(0,20,10); % For ten rings > theta = (pi/180)*[0:45:360]; % For eight angles > [R,T] = meshgrid(radius,theta); % Make radius/theta grid > X = R.*cos(T); % Convert grid to cartesian coordintes > Y = R.*sin(T); > Z = (corresponding values of Z in terms of X and Y) > surf(X,Y,Z) %Plot the sound pressure surface > > If you really do have only a ring, then you should be using 'plot3', not 'surf'. > > Roger Stafford thank you very much Roger^^ I got the idea from you. I clealy undertood how to work