#!/usr/bin/env perl use strict; use warnings; use PDL; # The number of intervals you require (your example shows 3) my $n = 3; my $a = pdl (0,6,18,7,19,3,10,2,12,4,8,9,1,15,11,11,19,17,0,9); my $b = pdl (0,1,2,3,4,5,6,7,8,9,10,10.5,11,11.5,12,12.5,13,13.5,14,14.5); my $gt = sequence($n)*5; # equivalent to pdl(0, 5, 10) for $n = 3 my $ltoe = (sequence($n)+1)*5; # equivalent to pdl(5, 10, 15) for $n = 3 my $expanded_a = $a->dummy(0,$n); my $expanded_b = $b->dummy(0,$n); my $gt_mask = $expanded_b > $gt; my $ltoe_mask = $expanded_b <= $ltoe; my $mask = $gt_mask & $ltoe_mask; my $mask_w_bad = $mask->setbadif($mask == 0); my $masked = $expanded_a * $mask_w_bad; my $medians = $masked->transpose->medover; print $medians, "\n"; exit;