#!/usr/bin/perl
open(OUT,">Pairwise_vrGVs_40K_bin_0.2%.xls");
print OUT "BinKey\tNo_of_pairs\t[2000000 possible pairs, 40000 vrGVs per inividual, freq = 0.2%]\n";
 $shared_rare_SNPs =0;
   $max = 0;
   %bin = ();
 for $pairs(1 .. 2000000)   #[~2000000 possible pairs for a sample of 2000 genetically non-related virtual individuals.]
    {
     for ( 1 .. 40000 ) {    #[each virtual inividual has 40000 very rare SNPs (vrGVs).]
                          $random = int(rand 500);  #[population frequency of rare SNPs = 0.2% = 1 in 500]
                                                    #(= probability of two virtual individuals sharing rare SNPs).]
                           if ($random == 295){
                                 $shared_rare_SNPs++;
                               }
             }
               if($shared_rare_SNPs > $max){$max=$shared_rare_SNPs;}
                 $temp = ($shared_rare_SNPs/10);
                  $int = int($temp);
                   $bin{$int}++;      
                 $shared_rare_SNPs =0;
    } 
         foreach $key (sort{$a<=>$b}(keys %bin)) {
          print OUT "$key  ==>  $bin{$key} \n";
         }
       print OUT "maximum number of shared SNPs is $max\n";
 print"maximum number of shared SNPs is $max\n";