#!/usr/bin/perl
use warnings;
use strict;
my @data = ( [1 .. 3], [4 .. 6], [7 .. 9] );

norm();

print join(", ", @{$_}), "\n" for @data;

sub norm{
    my $p=$#data; #I call the 100k x 3 array @data
    for(my $i=0;$i<=$p; $i++){ # iterates down @data
        my $norm=(($data[$i][0])**2+($data[$i][1])**2)**(1/2); #calculates the norm
        $data[$i][3] = $norm;
    }
}