$ perl -Mstrict -Mwarnings -e '
    use Data::Dumper;
    my @matrix;
    for my $i (0 .. 1) {
        for my $j (0 .. 1) {
            $matrix[$i][$j]{row} = $i;
            $matrix[$i][$j]{col} = $j;
        }
    }
    print Dumper \@matrix;
'
$VAR1 = [
          [
            {
              'col' => 0,
              'row' => 0
            },
            {
              'col' => 1,
              'row' => 0
            }
          ],
          [
            {
              'col' => 0,
              'row' => 1
            },
            {
              'col' => 1,
              'row' => 1
            }
          ]
        ];