Bugs and strange behaviours of Maxima with ratmx and sparse set to true
Subject: Bugs and strange behaviours of Maxima with ratmx and sparse set to true
From: Stefano Ferri
Date: Wed, 28 Jan 2009 01:01:50 +0100
> I think it could be better to use something like
> fast_linsolve or linsolve_by_lu rather than inversion.
>
>
Yes, maybe... but I need to keep all the things in a vector form, so
inversion is (I think) the best way to do it.
Anyway, this is not a problem, I've found the workaround to speed up the
inversion of sparse matrices. The problem is the bug with determinant
when sparse and ratmx are set to true, and the fact that I don't
understand why inversion of sparse matrices is so much fast by doing a
kill(all) before performing the inversion... I tryed to invert the 42x42
sparse matrix in the previous email without using the workaround, I
stopped the computation after 5-10 minuts with a Ctrl-c, no results were
displayed in that time...