my $z = long 5 * random(10,10);
my $dim = 3;
my (@out, $out);
for my $i ( 0 .. $z->dim(0) - $dim - 1) {
    for my $j ( 0 .. $z->dim(1) - $dim - 1) {
        push @out, $z($i:$i+$dim,$j:$j+$dim);
    }
}
$out = pdl @out;
print $out;