Path: news.mathworks.com!not-for-mail From: <HIDDEN> Newsgroups: comp.soft-sys.matlab Subject: Re: Inequality question Date: Fri, 17 Apr 2009 19:02:01 +0000 (UTC) Organization: Mitre Corp Lines: 44 Message-ID: <gsajn9$p5r$1@fred.mathworks.com> References: <gs9rs9$62a$1@fred.mathworks.com> <gs9v1d$7bd$1@fred.mathworks.com> <gsaftd$70n$1@fred.mathworks.com> <gsahll$72l$1@fred.mathworks.com> Reply-To: <HIDDEN> NNTP-Posting-Host: webapp-05-blr.mathworks.com Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 8bit X-Trace: fred.mathworks.com 1239994921 25787 172.30.248.35 (17 Apr 2009 19:02:01 GMT) X-Complaints-To: news@mathworks.com NNTP-Posting-Date: Fri, 17 Apr 2009 19:02:01 +0000 (UTC) X-Newsreader: MATLAB Central Newsreader 2318 Xref: news.mathworks.com comp.soft-sys.matlab:533606 "Sprinceana " <mihaispr@yahoo.com> wrote in message <gsahll$72l$1@fred.mathworks.com>... > > ... snip ... > > > > > Can you help me please? John outlined the solution for you in his original reply: Sprinceana " <mihaispr@yahoo.com> wrote in message <gs9rs9$62a$1@fred.mathworks.com>... > I have the following inequality: > > -2<=648424649/617174649-154164883/3085873245*y+46354883/3085873245*x-74824961/15429366225*y*x-100/74529*x^2-100/74529*y^2<=2 > No. You have a pair of inequalities, not a single inequality relationship. > Which is the best method to trace y=f(x) if we had an equation by type y-x=2 Define "trace" here. Do you wish to plot this relationship? Why not use plot? help plot lookfor plot The general scheme would seem trivial. 1. Generate a list of points x. 2. Compute y = f(x). 3. Delete those (x,y) pairs which fail to satisfy the pair of inequality relationships given above. 4. Use plot(x,y,'-') on those remaining points. ... snip ... John All you need to do is write the "trivial" MATLAB code. Whats the problem? What have you tried? Where are you stuck? What error messages do you get?