#!/usr/bin/perl

use Math::MatrixReal;
use strict;

my $mref = [
  [ 1, 2, 3, 4, 5, 6 ],
];

my $matrix = Math::MatrixReal->new_from_rows($mref);

my ($rows, $cols) = $matrix->dim();

for(my $currentcol = 1; $currentcol <= $cols / 2; $currentcol++) {
  $matrix->swap_col($currentcol, $cols - $currentcol + 1);
}