Eigensystem: different solution in V5.0 and V4.1 ??
- To: mathgroup at smc.vnet.net
- Subject: [mg48291] Eigensystem: different solution in V5.0 and V4.1 ??
- From: ivo.bleylevens at facburfdaw.unimaas.nl (Ivo bleylevens)
- Date: Sat, 22 May 2004 03:04:22 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
Hello all ! I am a dutch PhD student at the University of Maastricht and I have a question about some strange behaviour of the Mathematica's 5.0 function Eigensystem. I have an 512x512 non-symmetric complex matrix M. When i use the command eigsys = Eigensystem[M] in Mathematica 5.0, the eigenvalues were not the eigenvalues I expected ! I calculated exactly the same notebook in Mathematica version 4.1 and these eigenvalues look the same as the wanted eigenvalues !! Am i doing something wrong in version 5.0 ?? * I already tried to use the options of Eigensystem described at http://documents.wolfram.com/v5/Built-inFunctions/AdvancedDocumentation/LinearAlgebra/4.4.html but that also didn't help. * I tried to set the precision of Mathematica 5.0 with the command eigsys = Eigensystem[N[M, 30]] but that didn't help either ! * I also calculated the eigenvalues of the matrix M with another system using the functions EIG and EIGS (which makes use op the LAPACK functions. Mathematica 5 uses this functions also as described in the link above). The eigenvalues computed with this two functions are exactly similar with the eigenvalues calculated in Mathematica 4.1.... So in my opinion Mathematica 5.0 produces incorrect eigenvalues......can someone help me ??? Ivo Bleylevens Universiy of Maastricht