#!/usr/bin/perl

use warnings;
use strict;
use Data::Dumper;
use Data::Dump qw(pp);

my @results = (["chpt10_2", "sent. 2", "alice", "nsubj", "animals", "protect"],
               ["chpt12_1", "sent. 54", "bob", "nsubj", "cells", "protect"],
               ["chpt25_4", "sent. 47", "carol", "nsubj", "plants", "protect"],
               ["chpt34_1", "sent. 1", "dave", "nsubj", "cells", "protect"],
               ["chpt35_1", "sent. 2", "eli", "nsubj", "cells", "protect"],
               ["chpt38_1", "sent. 1", "fred", "nsubj", "animals", "protect"],
               ["chpt54_1", "sent. 1", "greg", "nsubj", "uticle", "protect"]
              );
my %freq;
foreach ( map{$_->[4]}@results) #feeds in list of animals, cells, uticle, etc.
{
   $freq{lc $_}++;
}


@results = sort {$freq{lc $b->[4]} <=> $freq{lc $a->[4]} #freq order
                                   or
                         $a->[0]  cmp $b->[0]            #text col 0      
                } @results; 

print pp(\@results);


__END__

[
  ["chpt12_1", "sent. 54", "bob", "nsubj", "cells", "protect"],
  ["chpt34_1", "sent. 1", "dave", "nsubj", "cells", "protect"],
  ["chpt35_1", "sent. 2", "eli", "nsubj", "cells", "protect"],
  ["chpt10_2", "sent. 2", "alice", "nsubj", "animals", "protect"],
  ["chpt38_1", "sent. 1", "fred", "nsubj", "animals", "protect"],
  ["chpt25_4", "sent. 47", "carol", "nsubj", "plants", "protect"],
  ["chpt54_1", "sent. 1", "greg", "nsubj", "uticle", "protect"],
]