in reply to Re^3: Fast sliding submatrix sums with PDL (inspired by PWC 248 task 2)
in thread Fast sliding submatrix sums with PDL (inspired by PWC 248 task 2)

Oops, sorry, one more: subtraction is not required of course, and, more importantly, next gen calculation expression can be split in 2 lines -- same 4 ops but presumably done in-place i.e. faster:

    $m &= $n == 4;
    $m |= $n == 3;

__END__

Game of Life!
Matrix: PDL: Long D [2000,2000], 10 generations
Faster+:   0.677 s

[download]
  • Comment on Re^4: Fast sliding submatrix sums with PDL (inspired by PWC 248 task 2)
  • Download Code

In Section Meditations