Hi,
is it possible to select a random number from an array containing 181014922 elements or even higher number of elements, something like 3,020,300,000. can PERL do that, or it has to be done in a complicated manner. regards sameet.

Regarding this I have actually written a longish program, I actually need to add one more nested loop in each elsif loop, I am pasting the code for reference. If there is a easier way out Please tell me 

#!/usr/bin/perl

use strict;
#use warnings;
use BeginPerlBioinfo;

srand ($$|time);
my $contig;
# This program will download the sequences from a given organism
my $organism;
print "Give the organism from where you want to download the sequences
+:\n";
$organism = <STDIN>;
chomp $organism;

#print "Give number of sequences to be generated";
#print "\n";
my $number = 10;
#chomp $number;

my @numbers = (1 .. $number);
foreach my $numbers(@numbers){
    if ($organism eq 'Homo Sapien'){
        my @chromosomes = qw\1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
+ 18 19 20 21 22 'X' 'Y'\;
        # pick a random chromosome from the chromosomes in humans
        my $chromosome = random_element(@chromosomes);
        #my $contig;
        print "Chromosome $chromosome\n";    
        # pick up a contig randomly from the number of contigs present
+ in each given chromosome
        # This is one more loop
        if ( my $chomosome eq '1'){
            my @contigs = (1 .. 30);
            my $contig = random_element(@contigs);
        } elsif ($chromosome eq '2'){
            my @contigs = (1 .. 28);
            my $contig = random_element(@contigs);
        } elsif ($chromosome eq  '3'){
            my @contigs = (1 .. 25);
            my $contig = random_element(@contigs);
        } elsif ($chromosome eq '4'){
            my @contigs = (1 .. 25);
            my $contig = random_element(@contigs);
        } elsif ($chromosome eq '5'){
            my @contigs = (1 .. 25);
            my $contig = random_element(@contigs);
        } elsif ($chromosome eq '6'){
            my @contigs = (1 .. 25);
            my $contig = random_element(@contigs);
        } elsif ($chromosome eq '7'){
            my @contigs = (1 .. 25);
            my $contig = random_element(@contigs);
        } elsif ($chromosome eq '8'){
            my @contigs = (1 .. 25);
            my $contig = random_element(@contigs);
        } elsif ($chromosome eq '9'){
            my @contigs = (1 .. 25);
            my $contig = random_element(@contigs);
        } elsif ($chromosome eq '10'){
                    my @contigs = (1 .. 25);
                    my $contig = random_element(@contigs);
        } elsif ($chromosome eq '11'){
            my @contigs = (1 .. 25);
            my $contig = random_element(@contigs);
        } elsif ($chromosome eq '12'){
            my @contigs = (1 .. 25);
            my $contig = random_element(@contigs);
        } elsif ($chromosome eq '13'){
            my @contigs = (1 .. 25);
            my $contig = random_element(@contigs);
        } elsif ($chromosome eq '14'){
            my @contigs = (1 .. 25);
            my $contig = random_element(@contigs);
        } elsif ($chromosome eq '15'){
            my @contigs = (1 .. 25);
            my $contig = random_element(@contigs);
        } elsif ($chromosome eq '16'){
            my @contigs = (1 .. 25);
            my $contig = random_element(@contigs);
        } elsif ($chromosome eq '17'){
            my @contigs = (1 .. 25);
            my $contig = random_element(@contigs);
        } elsif ($chromosome eq '18'){
            my @contigs = (1 .. 25);
            my $contig = random_element(@contigs);
        } elsif ($chromosome eq '19'){
            my @contigs = (1 .. 25);
            my $contig = random_element(@contigs);
        } elsif ($chromosome eq '20'){
            my @contigs = (1 .. 25);
            my $contig = random_element(@contigs);
        } elsif ($chromosome eq '21'){
            my @contigs = (1 .. 25);
            my $contig = random_element(@contigs);
        } elsif ($chromosome eq '22'){
            my @contigs = (1 .. 25);
            my $contig = random_element(@contigs);
        } elsif ($chromosome eq 'X'){
            my @contigs = (1 .. 25);
            my $contig = random_element(@contigs)
        } elsif ($chromosome eq 'Y'){
            my @contigs = (1 .. 25);
            my $contig = random_element(@contigs);
        }
        
        print " Contig $contig \n";

    }
}


################
#
##############

# random_element
#
# Sub routine thta picks up random element from a given array

sub random_element{
    my @array = @_;
    return $array [rand @array];
}

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janitored by ybiC: Balanced <readmore> tags around longish codeblock, especially for frontpaged root node. Also wee tiny format tweaks for legibility.

In reply to What is the limit of random number that can be selected by Sameet

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