I’ve got another question, is it possible instead of getting:
[[ 0  x  x]
 [ 3  4  x]
 [ x  7  8]
 [ x  x  11]]

To get a reverse stripe like this:
[[ x   x   2]
 [ x   4   5]
 [ 6   7   x]
 [ 9   x   x]]

Can’t figure out how to properly modify the function above. Thank you!