From: SourceForge.net <noreply@so...>  20080924 00:05:26

Bugs item #2125317, was opened at 20080923 18:30 Message generated for change (Comment added) made by rtoy You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=2125317&group_id=4933 Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Xmaxima or other UI Group: None >Status: Pending >Resolution: Invalid Priority: 5 Private: No Submitted By: Lindsay Dunseith (dunseith) Assigned to: Nobody/Anonymous (nobody) Summary: Multiplication of matrices Initial Comment: For the matrix " matrix M =([m,0],[0,m]), the power M^n is determined correctly. However, for other matrices, e.g. P =([3,1],[1,3])Maxima determines P^2 as matrix([9,1],[1,9]), instead of the correct: matrix([10,6],[6,10]) I haven't tried multiplying more general matrices, but does this mean there is a problem with matrix multiplication? Maxima build as follows: Maxima version: 5.15.0 Maxima build date: 17:36 4/20/2008 host type: i686pcmingw32 lispimplementationtype: GNU Common Lisp (GCL) lispimplementationversion: GCL 2.6.8  >Comment By: Raymond Toy (rtoy) Date: 20080923 20:05 Message: Please be more explicit and show exactly what you did. However, I suspect you used * to multiply matrices. This is an elementbyelement multiply. The matrix multiply operator is ".". So: p:matrix([3,1],[1,3]); p . p; matrix([10,6],[6,10]) Marking as pending/invalid.  You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=104933&aid=2125317&group_id=4933 