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Re: eigenvector rotation

• To: mathgroup at smc.vnet.net
• Subject: [mg46669] Re: eigenvector rotation
• From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
• Date: Fri, 27 Feb 2004 19:31:58 -0500 (EST)
• Organization: Universitaet Leipzig
• References: <c1luu7$o16$1@smc.vnet.net>
• Reply-to: kuska at informatik.uni-leipzig.de
• Sender: owner-wri-mathgroup at wolfram.com

Hi,

since Mathematica use the EISPACK routines you have to write
your own code to find the eigensystem and you can't use
any library because all numerical librarys use EISPACK
And I would expect that the effect comes form the Householder
rotation during the eigensystem computation.

Regards
  Jens

Bettina wrote:
> 
> Hi
> It seems, that when I calculate the eigensystem of a complex Hermitian
> matrix, th eigenvectors get rotated automatically in such a way, that
> the highest absolute valued eigenvector component becomes real. Since I
> need the unrotated result, how do I switch off this feature?
> Thanks for the help.
> Best regards
> Bettina