note space_monk One of the things to learn about any programming language is that your problem has almost certainly been addressed in some way before, and in this case there are PERL CPAN libraries like <a href="http://search.cpan.org/~ulpfr/Math-Matrix-0.5/Matrix.pm">Math::Matrix</a> and <a href="http://search.cpan.org/~leto/Math-MatrixReal-2.09/lib/Math/MatrixReal.pm">Math::MatrixReal</a> to avoid having to do any work. Using CPAN libraries also makes your code more maintainable as other people will have more chance of having come across the library concerned on CPAN than of understanding your custom code. <p>In answer to the input question, (and modifying an earlier answer) why not get your input as <code> while (<>) do { push @m2, [ split /,/, $_ ]; } </code> and then your script can get your input from any file or stdin....<br/> e.g. <code> ./myprogram.pl < d1.txt </code> </p> 1002795 1002795