Well, I am in the (not) quite lucky situation to be forced to maintan modules relying on Math::MatrixSparse
for $job, and I can tell you this module is, on the one hand, not prepared to do complex matrix arithmetics and, on the other hand, buggy and unmaintained. I have a plethora of patches and obvious fixes to this module and I even maintain an own updated version
for $job purposes.
Don't get me wrong: Math::MatrixSparse is a brilliant piece of Perl code. It is just that it is now old and it's stinking. Don't use it.