In the spirit of TMTOWTDI here's an alternative solution that uses Sort::Key to improve readability.

To further improve the readability (without too much memory being wasted) this version also creates a partially flattened collection of [filename, letter, dataref] chunks. <p. It could be simplified further, but I kept the letter key capturing enabled in case it was neccesary for solving the problem with actual data (versus the example data). 

#!/usr/bin/perl
use strict;
use warnings;
use Sort::Key qw(ikeysort);

my %hoh;

$hoh{'FILENAME1'}{'A'}{'weight'}=3000;
$hoh{'FILENAME1'}{'A'}{'intensity'}=2;

$hoh{'FILENAME1'}{'B'}{'weight'}=4000;
$hoh{'FILENAME1'}{'B'}{'intensity'}=3;

$hoh{'FILENAME2'}{'D'}{'weight'}=2000;
$hoh{'FILENAME2'}{'D'}{'intensity'}=7;

$hoh{'FILENAME2'}{'C'}{'weight'}=5000;
$hoh{'FILENAME2'}{'C'}{'intensity'}=3;

$hoh{'FILENAME3'}{'C'}{'weight'}=1000;
$hoh{'FILENAME3'}{'C'}{'intensity'}=4;

$hoh{'FILENAME3'}{'A'}{'weight'}=6000;
$hoh{'FILENAME3'}{'A'}{'intensity'}=3;



# Create a list of sets
# $set[0] = filename
# $set[1] = letter
# $set[2] = reference to the data for this filename-letter combination
my @sets;
for my $filename (keys %hoh) {
    push @sets, [$filename, $_,$hoh{$filename}{$_}] for keys %{$hoh{$f
+ilename}}
}
for my $set (ikeysort { $_->[2]{weight} } @sets) {
    my ($filename,$letter,$data) = @$set;
    my $weight    = $data->{weight};
    my $intensity = $data->{intensity};
    printf "weight: %4d intensity: %d Filename: %s\n",$weight,$intensi
+ty,$filename;
}

[download]

In reply to Re: HoH problem by imp
in thread HoH problem by tamaguchi

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.