matrixexp no longer works with a really easy matrix
Subject: matrixexp no longer works with a really easy matrix
From: Barton Willis
Date: Wed, 19 Jun 2013 10:24:37 +0000
This bug is due to circa January 2013 changes to matrix inversion. A workaround is to set ratmx to true:
Maxima branch_5_30_base_98_g29f9239_dirty http://maxima.sourceforge.net
using Lisp Clozure Common Lisp Version 1.9-r15764 (WindowsX8632)
(%i1) matrixexp(matrix([%i*%pi]));
Unable to find the spectral representation
(%i2) matrixexp(matrix([%i*%pi])), ratmx=true;
(%o2) - 1
--Barton
________________________________
From: maxima-bounces at math.utexas.edu [maxima-bounces at math.utexas.edu] on behalf of Karl-Dieter Crisman [kcrisman at gmail.com]
Sent: Tuesday, June 18, 2013 13:31
To: maxima at math.utexas.edu
Subject: matrixexp no longer works with a really easy matrix
Is the following by design or a bug? Given http://www.ma.utexas.edu/pipermail/maxima/2006/003031.html I'm not sure how to overcome this directly. Or is there an obvious recent change that made this break? Thanks!
With 5.29.1:
Maxima 5.29.1 http://maxima.sourceforge.net
using Lisp ECL 12.12.1
Distributed under the GNU Public License. See the file COPYING.
Dedicated to the memory of William Schelter.
The function bug_report() provides bug reporting information.
(%i1) m: matrix([%i*%pi]);
(%o1) [ %i %pi ]
(%i4) matrixexp(m), keepfloat:true;
(%o4) - 1
(%i5) matrixexp(m),keepfloat:false;
(%o5) - 1
which is good. In 5.30, though, we have
(%i1) m: matrix([%i*%pi]);
(%o1) [ %i %pi ]
(%i6) matrixexp(m),keepfloat:true;
Unable to find the spectral representation
-- an error. To debug this try: debugmode(true);
(%i7) matrixexp(m),keepfloat:false;
Unable to find the spectral representation
-- an error. To debug this try: debugmode(true);