You didn't change anything but the names of the variables?!? That's still the same as

my @Matrix = (0) x (361*2);
[download]

You want to end up with something equivalent to

my @Matrix = (
   [ (0) x 361 ],
   [ (0) x 361 ],
   [ (0) x 361 ],
   ... 355 more ...
   [ (0) x 361 ],
   [ (0) x 361 ],
   [ (0) x 361 ],
);
[download]

Unless you want 361 identical lines, you'll want some kind of loop...

(I'm treating this as homework. Whether it's personal or assigned doesn't matter to me.)