Re: Eigensystem[] bug in Mathematica 5.0 (fixed in 5.0.1)
- To: mathgroup at smc.vnet.net
- Subject: [mg48548] Re: Eigensystem[] bug in Mathematica 5.0 (fixed in 5.0.1)
- From: ivo.bleylevens at facburfdaw.unimaas.nl (Ivo bleylevens)
- Date: Fri, 4 Jun 2004 04:51:11 -0400 (EDT)
- References: <c9ccon$6ha$1@smc.vnet.net> <c9ec93$ga3$1@smc.vnet.net> <c9k49r$fhu$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Hi everyone, I had the same problem as Marcus Stollsteimer discovered. I had a asymetric complex 512x512 matrix and the eigenvalues Mathematica 5.0 calculated were totally wrong. Check also post http://groups.google.com/groups?q=bleylevens&hl=en&lr=&ie=UTF-8&selm=c8mu5a%248nu%241%40smc.vnet.net&rnum=1. Wolfram reported to me that this is fixed in version 5.0.1. And it was, but........ With a 1024x0124 matrix the results are still wrong !! I yet don't know if the reason for that is that the matrix is badly scaled or that it is a matter of numerical inprecizion or something else.......in this 1024x1024 case the results of - Mathematica 4.1 on a Pentium 4 - Mathematica 5.0 on a Pentium 4 - Mathematica 5.0.1 on a Pentium 4 - Mathematica 5.0 on an AMD - Mathematica 5.0.1 on an AMD In the 512x512 case only the eigenvalues of Mathematica 5.0 on a Pentium 4 were different. So I conclude that in the 1024x1024 case Mathematica is doing wrong by a matter of numerical inprecizion .....I think..... Any suggestions ?? Ivo Bleylevens University of Maastricht