Many thanks.
For this bug, it may be interesting to note that, by little modification
(%i1) b:matrix([0,-1/4,0,0],[1/4,0,0,0],[0,0,0,-1/4],[0,0,1/4,0])$
(%i2) eigenvalues(4*b);
Maxima give the correct answer,
(%o2) [[-%i,%i],[2,2]]
Noparit
--- On Wed, 12/10/08, Barton Willis <willisb at unk.edu> wrote:
From: Barton Willis <willisb at unk.edu>
Subject: Re: [Maxima] Can't find eigenvalues
To: fscinpr at yahoo.com
Cc: maxima at math.utexas.edu
Date: Wednesday, December 10, 2008, 3:25 AM
You found a bug, I'm sorry to say. I'm pretty sure that the bug is due
to a faulty computation of the multiplicities of the roots of the
characteristic polynomial:
(%i26) solve(g33664^2*(g33664^2+1/16)+(g33664^2+1/16)/16,g33664);
(%o26) [g33664=-%i/4,g33664=%i/4]
(%i27) multiplicities;
(%o27) [1,1]
I think (%o27) should be [2,2]. I can't think of a workaround; I'll
file a bug report.
Barton
-----maxima-bounces at math.utexas.edu wrote: -----
>I'm?trying?to?find?the?eigenvalues?of?a?simple?matrix
>
>b:matrix([0,-1/4,0,0],[1/4,0,0,0],[0,0,0,-1/4],[0,0,1/4,0]);
>
>by
>
>eigenvalues(b);
>
>But?Maxima?give?me
>
>part?fell?off?end.
>#0:
>eigenvalues(mat=matrix([0,-1/4,0,0],[1/4,0,0,0],[0,0,0,-1/4],[0,0,1/4,0]))
>(eigen.mac?line?94)
>--?an?error.??To?debug?this?try?debugmode(true);
>
>What?wrong?with?this??Can?anyone?help?
>
>Noparit?Jinuntuya
>Department?of?Physics,?Kasetsart?University
>Thailand.
>
>
>
>
>
>_______________________________________________
>Maxima?mailing?list
>Maxima at math.utexas.edu
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