Re: Eigensystem Bug? OS-X
- To: mathgroup at smc.vnet.net
- Subject: [mg56132] Re: Eigensystem Bug? OS-X
- From: Peter Pein <petsie at arcor.de>
- Date: Sat, 16 Apr 2005 03:52:25 -0400 (EDT)
- References: <d3o0f3$bnc$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Only a guess, because I've got a windows-pc:
What happens if you try Eigenvectors[Rationalize@mat] ?
Erich Mueller wrote:
> I have some strange behavior of Eigensystem and Eigenvectors [but not
> Eigenvalues] on my G5 running OS-X 10.3.8, and Mathematica 5.1.0.0.
>
> The Kernel Hangs when I try to calculate the Eigenvectors of the 18x18
> Matrix at the end of this message. [Its the smallest matrix for which I
> have the problem.] It does not respond to an "Abort Evaluation", or
> "Interupt Evaluation Signal", and I must kill it from the terminal.
>
> There is no problem finding the eigenvalues of this same matrix on a PC.
> Is there someone who can suggest a fix/workaround? Failing that, is
> there anyone with a mac who can verify the problem?
>
> Thanks,
> Erich
>
>
> {{-4., 1., 1., 1., 0., 0., 1., 0., 0., 0., 0. + 1.*I, 0. + 1.*I, 0. -
> 1.*I, 0., 0., 0. - 1.*I, 0., 0.},
> {1., -4., 1., 0., 1., 0., 0., 1., 0., 0. + 1.*I, 0., 0. + 1.*I, 0., 0.
> - 1.*I, 0., 0., 0. - 1.*I, 0.},
> {1., 1., -4., 0., 0., 1., 0., 0., 1., 0. + 1.*I, 0. + 1.*I, 0., 0.,
> 0., 0. - 1.*I, 0., 0., 0. - 1.*I},
> {1., 0., 0., -4., 1., 1., 1., 0., 0., 0. - 1.*I, 0., 0., 0., 0. +
> 1.*I, 0. + 1.*I, 0. - 1.*I, 0., 0.},
> {0., 1., 0., 1., -4., 1., 0., 1., 0., 0., 0. - 1.*I, 0., 0. + 1.*I,
> 0., 0. + 1.*I, 0., 0. - 1.*I, 0.},
> {0., 0., 1., 1., 1., -4., 0., 0., 1., 0., 0., 0. - 1.*I, 0. + 1.*I, 0.
> + 1.*I, 0., 0., 0., 0. - 1.*I},
> {1., 0., 0., 1., 0., 0., -4., 1., 1., 0. - 1.*I, 0., 0., 0. - 1.*I,
> 0., 0., 0., 0. + 1.*I, 0. + 1.*I},
> {0., 1., 0., 0., 1., 0., 1., -4., 1., 0., 0. - 1.*I, 0., 0., 0. -
> 1.*I, 0., 0. + 1.*I, 0., 0. + 1.*I},
> {0., 0., 1., 0., 0., 1., 1., 1., -4., 0., 0., 0. - 1.*I, 0., 0., 0. -
> 1.*I, 0. + 1.*I, 0. + 1.*I, 0.},
> {0., 0. - 1.*I, 0. - 1.*I, 0. + 1.*I, 0., 0., 0. + 1.*I, 0., 0., 4.,
> -1., -1., -1., 0., 0., -1., 0., 0.},
> {0. - 1.*I, 0., 0. - 1.*I, 0., 0. + 1.*I, 0., 0., 0. + 1.*I, 0., -1.,
> 4., -1., 0., -1., 0., 0., -1., 0.},
> {0. - 1.*I, 0. - 1.*I, 0., 0., 0., 0. + 1.*I, 0., 0., 0. + 1.*I, -1.,
> -1., 4., 0., 0., -1., 0., 0., -1.},
> {0. + 1.*I, 0., 0., 0., 0. - 1.*I, 0. - 1.*I, 0. + 1.*I, 0., 0., -1.,
> 0., 0., 4., -1., -1., -1., 0., 0.},
> {0., 0. + 1.*I, 0., 0. - 1.*I, 0., 0. - 1.*I, 0., 0. + 1.*I, 0., 0.,
> -1., 0., -1., 4., -1., 0., -1., 0.},
> {0., 0., 0. + 1.*I, 0. - 1.*I, 0. - 1.*I, 0., 0., 0., 0. + 1.*I, 0.,
> 0., -1., -1., -1., 4., 0., 0., -1.},
> {0. + 1.*I, 0., 0., 0. + 1.*I, 0., 0., 0., 0. - 1.*I, 0. - 1.*I, -1.,
> 0., 0., -1., 0., 0., 4., -1., -1.},
> {0., 0. + 1.*I, 0., 0., 0. + 1.*I, 0., 0. - 1.*I, 0., 0. - 1.*I, 0.,
> -1., 0., 0., -1., 0., -1., 4., -1.},
> {0., 0., 0. + 1.*I, 0., 0., 0. + 1.*I, 0. - 1.*I, 0. - 1.*I, 0., 0.,
> 0., -1., 0., 0., -1., -1., -1., 4.}}
>
--
Peter Pein
Berlin