#!/usr/bin/perl

use v5.24;
use warnings;
use PDL;

my $q = ones(5,5,5,5);
say 'q:          ', $q->info;
say 'ndcoords:   ', ndcoords($q)->info;
say 'range:      ', $q->range(ndcoords($q), 2, 'p')->info;
say '2x2x2x2 sum:', $q->range(ndcoords($q), 2, 'p')->reorder(4,5,6,7,0,1,2,3)->clump(4)->sumover;

__DATA__
[
 [
  [
   [9 9 9 9 9]
   [9 9 9 8 8]
   [8 8 8 8 8]
   [8 8 8 8 8]
   [8 8 8 8 8]
  ]
  [
   [8 8 8 8 8]
   [8 8 8 8 8]
   [8 8 8 8 8]
   [8 8 8 8 8]
   [8 8 8 8 8]
  ]
...