Path: news.mathworks.com!not-for-mail From: <HIDDEN> Newsgroups: comp.soft-sys.matlab Subject: Re: eigenvectors sign problem Date: Mon, 11 Jul 2011 00:38:09 +0000 (UTC) Organization: University of Miami Lines: 11 Message-ID: <ivdglh$ng4$1@newscl01ah.mathworks.com> References: <iot0fc$ii4$1@fred.mathworks.com> Reply-To: <HIDDEN> NNTP-Posting-Host: www-02-blr.mathworks.com Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Trace: newscl01ah.mathworks.com 1310344689 24068 172.30.248.47 (11 Jul 2011 00:38:09 GMT) X-Complaints-To: news@mathworks.com NNTP-Posting-Date: Mon, 11 Jul 2011 00:38:09 +0000 (UTC) X-Newsreader: MATLAB Central Newsreader 19787 Xref: news.mathworks.com comp.soft-sys.matlab:735752 "roman" wrote in message <iot0fc$ii4$1@fred.mathworks.com>... > Hello, > I'm working on a stress field problem and i want to find the eigenvector of a real symmetric matrix. When using eig() i get signs switched randomly, that apparently is common problem using this function. I understand that even if the change is switched the physical meaning of the eigenvector is the same, but I'd need to get the right sign to plot some trajectories, and the function streamslice seems not to like very much when signs are switched. I read in other posts that you can solve this by multiplying a component of the eigenvector by a factor, but I actually did not understand how to put this in practice. > Any help would be appreciated, > Alberto Hi alberto, Did you find a solution to your problem? That is, a tensor line integration code (ideally in Matlab)? Francisco