I think the more appropriate module is PDL::Matrix

use PDL::Matrix;
open my $fh, "<file" or die $!;
my (@left, @right) = ((),());
while( <$fh> ) {
    chop;
    my ( $left, $right ) = split ',';
    push @left, $left;
    push @right, $right;
}
my $m = PDL::Matrix->pdl([\@left,\@right]);
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