I wrote a Vector.pm module when I was exploring how to do perl math with Inline::C, which might be a useful example for people thinking of going that route.

While I didn't try to put in more than the basics, it does let you create and work with big vectors of doubles, like this:

 use Vector qw(vector);
 my $a = vector( size=>10000, first=>0.0, by=>0.01 );
 my $b = sin($a);
 my $c = $a + $b;
 print $c->[200];
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You can find the source code, documentation, and a test suite at http://cs.marlboro.edu/code/perl/modules/Math/Vector/