#!/usr/bin/perl 

use strict;
use warnings;
use Algorithm::Cluster;

my $data = [
[],
[3],
[10,10],
[10,10,3],
[10,10,3,3],
[10,10,3,2,3],
[10,10,3,3,3,3],
[10,10,7,10,7,8,10]
];

print "-------[pairwise average linkage]-------\n";

my %params = (
    method     =>       'a',
    data       =>     $data
);

my ($i,$j,$n);

my $tree = Algorithm::Cluster::treecluster(%params);

$n = $tree->length;
for ($i = 0; $i < $n; $i++) {
    my $node = $tree->get($i);
    printf("%3d: %3d %3d %7.3f\n",-1-$i,$node->left,$node->right,$node->distance);
}