If you're getting the expected results and know for certain that the values may not be initialized then you can just turn off warnings in that area e.g

{
  no warnings 'uninitialized';
  for(0..3) {
    ($sums[$i])->[$_][$j] += $vals[$_+1];
    if($ts >= 21) {
      $sums[$i]->[4][$j] += $vals[5];
      $sums[$i]->[5][$j] += $vals[6];
    }
  }
  $totals[$i]->[$j]->[0]++;
}
[download]

I really don't recommend doing this every time you get an uninitialized error, but if you expect there to be uninitialized values and it's a hassle to initialize them (see. chance for more bugs to creep in) then this can be very handy.
HTH

_________
broquaint