#!/usr/bin/perl -w
# This just illustrates what the correlation_matrix() function does.
use strict;
use Statistics::RankCorrelation;
use List::Permutor;
my $x = List::Permutor->new( qw( 1 2 3 4 ) );
my %seen;
my $i = 0;
while( my @x = $x->next ) {
    next if exists $seen{"@x"};  # Don't show duplicate permutations.
    $seen{"@x"} = undef;
    my $m = Statistics::RankCorrelation::correlation_matrix( \@x );
    printf "%d: %s =>\n%s\n",
        ++$i, join( ' ', @x ), join( "\n", map{"\t@$_"} @$m );
}