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Re: Eigensystem Bug? OS-X

  • To: mathgroup at smc.vnet.net
  • Subject: [mg56115] Re: Eigensystem Bug? OS-X
  • From: "Jens-Peer Kuska" <kuska at informatik.uni-leipzig.de>
  • Date: Sat, 16 Apr 2005 03:51:48 -0400 (EDT)
  • Organization: Uni Leipzig
  • References: <d3o0f3$bnc$1@smc.vnet.net>
  • Sender: owner-wri-mathgroup at wolfram.com

Hi,

try

Eigensystem[Map[SetPrecision[#, 50] 
&,yourMatrix,{2}]]

I expect a problem in the extern numerical 
librarys and

this should switch to the inter multi-precision 
funcitons.

Regards

  Jens



"Erich Mueller" <em256 at NOSPAM.cornell.edu> schrieb 
im Newsbeitrag news:d3o0f3$bnc$1 at smc.vnet.net...
>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.}}
> 



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