#!/usr/bin/env perl
use strict;
use warnings;

use PDL;
use PDL::NiceSlice;

my $dec = pdl [[1,1,2,2,3],[10,15,13,11,6]];
my $groups_vec = $dec(:,0);
my $groups = $groups_vec->uniq;
my $groups_t = $groups->transpose;
my $values = $dec(:,1);
my $masks = ($groups_t == $groups_vec);
my $group_values = $masks*$values;
my $max_of_each_group = $group_values->maximum;
my $final_pdl = pdl($groups, $max_of_each_group)->transpose;



print "Original Data: $dec\n";
print "Groups: $groups\n";
print "Transposed Groups: $groups_t\n";
print "Masks: $masks\n";
print "Group values: $group_values\n";
print "Max of each group: $max_of_each_group\n";
print "Final pdl: $final_pdl\n";

exit;

##</code><code>##

Original Data:
[
 [ 1  1  2  2  3]
 [10 15 13 11  6]
]

Groups: [1 2 3]
Transposed Groups:
[
 [1]
 [2]
 [3]
]

Masks:
[
 [1 1 0 0 0]
 [0 0 1 1 0]
 [0 0 0 0 1]
]

Group values:
[
 [10 15  0  0  0]
 [ 0  0 13 11  0]
 [ 0  0  0  0  6]
]

Max of each group: [15 13 6]
Final pdl:
[
 [ 1 15]
 [ 2 13]
 [ 3  6]
]