Re: How to compare hash values within the same hash?

[Marshall]

I think you want the peg counts (3rd printout below), but I showed some other stuff just for fun.

#!usr/bin/perl -w
use strict;
#http://perlmonks.org/?node_id=1055552

my %hash = 
(
  key1 => 10,
  key3 => 3,
  key2 => 10,
  key4 => 5,
  key5 => 10,
  key6 => 3,
);

# The keys don't matter.
# What matters is the histogram of the values.

my %histo;    #histogram of each key's summary data
my %pegs;     #peg count's of each key

#a bit brain boggling, but it works for a sum...
#the (my $value's) are pre-computed at start of the loop
#

foreach my $value (values %hash)
{
    $pegs{$value}++;
    $histo{$value}+=$value;     
}

#
# various print formats...
#
print "histo sort by key:\n";
foreach my $x (sort {$a <=> $b} keys %histo)
{
   print "$x => $histo{$x}\n";
}

print "\nhisto sort by inverse value:\n";
foreach my $x (sort {$histo{$b} <=> $histo{$a}} keys %histo)
{
  print "$x => $histo{$x}\n";
}

print "\nPeg counts of values\n";
foreach my $x (sort {$pegs{$a} <=> $pegs{$b}} keys %pegs)
{
  print "$x => $pegs{$x}\n";
}

=summary of prints:

sort by key of sums:
3 => 6   #keys 3,6
5 => 5   #keys 5
10 => 30 #keys 1,2,5

sort by inverse value of sums: (note swap of $b and $a)
#I did that to make it a bit more interesting...
10 => 30
3 => 6
5 => 5

Peg counts of values: (value and number of times seen)
5 => 1
3 => 2
10 => 3
=cut

There are a number of ways to present the max (eg 10 => 3) peg count, but what do you want if say 3=>3 also?