Re: eigenvectors is taking lot of time
- To: mathgroup at smc.vnet.net
- Subject: [mg82615] Re: eigenvectors is taking lot of time
- From: Scott Hemphill <hemphill at hemphills.net>
- Date: Fri, 26 Oct 2007 05:21:53 -0400 (EDT)
- References: <ffppmk$l0d$1@smc.vnet.net>
- Reply-to: hemphill at alumni.caltech.edu
vickyisai at gmail.com writes: > Hi all > > I am trying to calculate eigenvectors of a 30 X 30 matrix. and > mathematica is still just "running". > Is the any way to get the eigenvectors quickly. > > After 45 mins ,it was still running and displayed a message "limit of > "some number here(4096) exceeded" > > i wanted eigen values and vectors both ..so i tried eigensystem....but > tat also took long, so i switched to individualfunctions of > eigenvalues and eigenvectors. > > I aborted it...shud i execute it again and wait for longer? > I use Mathematica 5.2 and got a AMD Turion 2.2 Gz, does tat matter for > a 30 x 30 matrix?? If the elements of your matrix are approximate numbers, then you will quickly get results. If the elements of your matrix are exact numbers, then it may be too hard to get exact results, so turn your matrix into approximate numbers. m = N[m]; You can ask for extra precision if you want: m = N[m,32]; If the elements of your matrix are symbolic then this is too hard a problem. Scott -- Scott Hemphill hemphill at alumni.caltech.edu "This isn't flying. This is falling, with style." -- Buzz Lightyear