Re: Eigenvalues computation

[A. Scottedward Hodel]

Octave's eig routine does not sort eigenvalues;  if you're
trying to track eigenvalue variation (which I've also been
doing for my work here), you may wish to use
the sortcom routine that I wrote for the octave controls
toolbox ftp://ftp.eng.auburn.edu/pub/hodel.  There's 
an updated version that I need to put out that will take
the same calling syntax as the sort routine; the current
version only returns the sorted values and doesn't always
put conjugate pairs in the same order.  I'll have the new version
out later today.

A S Hodel Dept Elect Eng, Auburn Univ,AL  36849-5201
On leave at NASA Marshall Space Flight Center (205) 544-1426

----------
>From: Daniel Tourde <address@hidden>
>To: address@hidden, address@hidden
>Subject: Eigenvalues computation
>Date: Tue, Jul 28, 1998, 10:16 AM
>

>Hi !
>
>I would like to trace the variation of the eigenvalues of a matrix D(k)
>in function of k. Until now I have considered that Octave kept the same
>order for my eigenvalues but in view of some strange results I have I'm
>wondering if at a certain step of my computation the order does not
>change (lambda8 <-> lambda9 for instance).
>
>So, here is my question :
>Does octave classify the eigenvalues of a matrix ?
>If yes, how ?
>If yes, how can I force Octave to keep this classification all along my
>computation of lambda(k) x = D(k) x ?
>If no, what can I do ? ....
>
>Thanks for any answer. Best regards
>
>   Daniel Tourde
>-- 
>*********************************************************************
>Daniel TOURDE                                   E-mail : address@hidden
>The Aeronautical Research Institute of Sweden   Tel : +46 8 634 13 44
>P.O. Box 11021 S-161 11 BROMMA, Sweden          Fax : +46 8  25 34 81
>*********************************************************************
>