Subject: Calculation of eigenvalues, eigenvectors fails
From: Felix E. Klee
Date: Mon, 21 Aug 2006 22:31:56 +0200
I recently installed Maxima under LINUX for someone who needs to do
matrix calculations. Unfortunately, the first test we threw at it
failed:
Maxima 5.9.3 http://maxima.sourceforge.net
Using Lisp CLISP 2.35 (2005-08-29)
Distributed under the GNU Public License. See the file COPYING.
Dedicated to the memory of William Schelter.
This is a development version of Maxima. The function bug_report()
provides bug reporting information.
(%i1) eigenvectors(matrix([0,3,2],[3,0,1],[2,1,0]));
`quotient' by `zero'
#0: eigenvectors(mat=matrix([0,3,2],[3,0,1],[2,1,0]))
#1: eigenvectors(?_l=[matrix([0,3,2],[3,0,1],[2,1,0])])
-- an error. Quitting. To debug this try debugmode(true);
(%i2)
I tried this with versions 5.9.3 and 5.9.3.99rc2. Also, I tried whether
things improve when setting "gcd:'spmod$", a hint that I found in the
archives of this mailing list. Result: The eigenvalues are now
calculated, but not the eigenvectors.
Does anyone have an idea how to get Maxima to calculate eigenvalues and
eigenvectors reliably? Is it possible to tell Maxima to do the
calculations using floating point numbers, which in this case -
according to the user - would be preferred as a result?
--
Felix E. Klee