Hmmm, I wonder how far you've looked - I would refer you to Chapter 7 of Mastering Algorithms with Perl (referred to directly in Mastering Algorithms with Perl) - which refers to Math::MatrixReal & PDL (PDL having been mentioned elsewhere (Re: Multiplying matrices by zentara) in this thread) and I also found this (Math::GSL::Matrix) on the 3rd page of a search within CPAN - but these all concern mathematical matrices i.e. grids of numbers, whereas your example data isn't actually a matrix.