Hi Monks,
I'm having a problem with the attached script. When calling the function two times in a row, the 2nd time is by far slower.
The memory usage stays roughly the same, and it does not seem to be an issue of paging either. I wonder if it has to do with some fragmentation?
Is my data structure "too complicated"??
I use it on an XP OS with 2G RAM. Perl 5.8.8 Build 819

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

CheckAllPairs();
CheckAllPairs();

sub CheckAllPairs{
        my $abs_time_res=50;
        my $max_peak_time=2050;
        my $subj_num;
        my $region;
        my $region1;
        my $region2;
        my $time;
        my $peaks;
        my @act_list1;
        my @act_list2;
        my $i;
        my $j;
        my $key;
        my $delta;
        my %map;
        my $start_A;
        my $end_A;
        my $start_B;
        my $end_B;

        my @region_list = (1..38);
        my @main_subjects_list = (1..38);
        
        $start_A = (times)[0];
        foreach $region (@region_list) {
                foreach $subj_num (@main_subjects_list){
                        for $time (0..$max_peak_time){
                                if(rand(1000)<3){
                                        push(@{$peaks->{$region}{$subj
+_num}}, $time);
                                }
                        }
                }
        }
        $end_A = (times)[0];
        printf "Section A took %.4f CPU seconds\n", $end_A - $start_A;
        $start_B = (times)[0];
        foreach $region1 (@region_list) {
                foreach $region2 (@region_list) {
                        if($region2<$region1){
                                next;
                        }
                        $key=$region1 . ':' . $region2;
                        foreach $subj_num (@main_subjects_list){
                                if(!exists($peaks->{$region1}{$subj_nu
+m}) || !exists($peaks->{$region2}{$subj_num})){
                                        next;
                                }
                                @act_list1=@{$peaks->{$region1}{$subj_
+num}};
                                @act_list2=@{$peaks->{$region2}{$subj_
+num}};
                                foreach $i (@act_list1){
                                        foreach $j (@act_list2){
                                                $time=int($i/$abs_time
+_res);
                                                $delta=int(($j-$i)/$ab
+s_time_res)+int($max_peak_time/$abs_time_res);
                                                $map{$key}{$subj_num}[
+$time][$delta]=1;
                                        }
                                }

                        }
                }
        }
        $end_B = (times)[0];
        printf "Section B took %.4f CPU seconds\n", $end_B - $start_B;


        return;
}
[download]

---

---

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! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

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:
	&		&
	<		&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.