in reply to sorting question

This assumes you will have the same amount of x's as y's or you'll get a whole lot of uninitialized warnings (granted there are ways around that):
use strict; use warnings; my $xy = [ [5,4,2,3,1,12], [2,9,2,3,4,5] ]; my @xy; #push x's and corresponding y coor. in #a slight different AoA; for ( 0 .. $#{$xy->[0]} ){ push @xy, [ $xy->[0][$_], $xy->[1][$_] ]; } #sort it by y; @xy = sort { $a->[1] <=> $b->[1] } @xy; print "value of x with largest y = $xy[-1][0]\n"; print "largest y = $xy[-1][1]\n";