#!/usr/bin/perl -w
use strict;

my %hoh_test;

$hoh_test{foo1}{bar} = -0.12697;
$hoh_test{foo1}{baz} = -0.000398154;
$hoh_test{foo2}{bar} = -4.0183e-05;
$hoh_test{foo2}{baz} = 0;
$hoh_test{foo3}{bar} = 9.966003977e-06;
$hoh_test{foo3}{baz} = 0.0001939;

# sort descending by value
my %sorter;
foreach my $foo (keys(%hoh_test))
{
    foreach my $ba (sort {$hoh_test{$foo}{$b} <=> $hoh_test{$foo}{$a}} keys(%{$hoh_test{$foo}}))
    {
        push @{$sorter{$hoh_test{$foo}{$ba}}}, [ $foo, $ba ];
    }
}

foreach my $val (sort {$a<=>$b} keys %sorter)
{
    foreach my $keys ( @{$sorter{$val}} ) {
        print "foo: $$keys[0], ba: $$keys[1], value: $hoh_test{$$keys[0]}{$$keys[1]}\n";
    }
}