You do realize that you have full access to the source code, right?

sub cross_product {
  my $vectors = shift;
  my $class = ref($vectors);

  my $dimensions = @{$vectors->[0]};
  return undef
    unless $dimensions == @$vectors + 1;
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indicates that cross_product() expects to receive a single (blessed) matrix that contains the vectors to be productizedmultiplied.

I'm not saying that this access excuses unclear documentation, of course. But I suspect you can use the source to answer your own questions faster then you'll get answers from someone else. Producing a patch for the module might be a good result of your investigation.

I know, I know. I gave the source code a quick look, didn't quite understand all of what it was doing (being a lowly noobie perl programmer) and begged for help here. Maybe if I have time I'll go back and play around with it.

Thanks.

Ryan

The comment by tye translates into the syntax for your example:

$a = new Math::Matrix ([1], [2], [3]);
$x = new Math::Matrix ([4], [5], [6]);

$f=new Math::Matrix([1, 2, 3],[4, 5, 6]);
$f=$f->cross_product;
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Kind of a bizarre syntax. Thanks for everyone who's posted here for helping me put the pieces together to sort this out. I don't know how to write a patch, or I would do so...

#!/usr/bin/perl
use warnings;
use strict;
use Math::VectorReal;

my $a = vector( 1, 2, 3 );
my $b = vector( 4, 5, 6 );

print "Vector as string (MatrixReal default format)\n\$a => ", $a;
print $a->stringify( "Formated Output   \$a => { %g, %g, %g }\n" );

print "Vector as string (MatrixReal default format)\n\$b => ", $b;
print $b->stringify( "Formated Output   \$b => { %g, %g, %g }\n" );

print 'dot product $a . $b =', $a . $b, "\n\n";
print 'cross product $a x $b =', $a x $b, "\n\n";
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Thanks. I'll give that a try!

Ryan