#!/usr/bin/perl
use warnings;
use strict;
use PDL::LiteF;

my $a = pdl([ 
          [1,   ,     ,     ],
          [4,  -5,    ,     ],
	  [7,  -8,   -9,    ],
	  [17, -18, -90,  114],
	  ]);

print $a,"\n";

my $b = transpose($a);
print "$b\n";

my $c = $a+ $b;
print "$c\n";

my $d = $a->diagonal(0,1);
print "$d\nNeeds to be padded with zeros and subtracted from  \$c\n";

print "I'll leave that to you. :-)\n";