NAME Algorithm::Evolutionary::Op::Breeder_Diverser - Like Breeder, only it tries to cross only individuals that are different

SYNOPSIS

    use Algorithm::Evolutionary qw( Individual::BitString 
      Op::Mutation Op::Crossover
      Op::RouletteWheel
      Op::Breeder_Diverser);
    use Algorithm::Evolutionary::Utils qw(average);
    my @pop;
    my $number_of_bits = 20;
    my $population_size = 20;
    my $replacement_rate = 0.5;
    for ( 1..$population_size ) {
      my $indi = new Algorithm::Evolutionary::Individual::BitString $number_of_bits ; #Creates random individual
      $indi->evaluate( $onemax );
      push( @pop, $indi );
    }
    my $m =  new Algorithm::Evolutionary::Op::Mutation 0.5;
    my $c = new Algorithm::Evolutionary::Op::Crossover; #Classical 2-point crossover
    my $selector = new Algorithm::Evolutionary::Op::RouletteWheel $population_size; #One of the possible selectors
    my $generation = 
      new Algorithm::Evolutionary::Op::Breeder_Diverser( $selector, [$m, $c] );
    my @sortPop = sort { $b->Fitness() <=> $a->Fitness() } @pop;
    my $bestIndi = $sortPop[0];
    my $previous_average = average( \@sortPop );
    $generation->apply( \@sortPop );

Base Class

Algorithm::Evolutionary::Op::Base

DESCRIPTION

Breeder part of the evolutionary algorithm; takes a population and returns another created from the first. Different from Algorithm::Evolutionary::Op::Breeder: tries to avoid crossover among the same individuals and also re-creating an individual already in the pool. In that sense it "diverses", tries to diversify the population. In general, it works better in environments where high diversity is needed (like, for instance, in Algorithm::MasterMind.

METHODS

new( $ref_to_operator_array[, $selector = new Algorithm::Evolutionary::Op::Tournament_Selection 2 ] )

Creates a breeder, with a selector and array of operators

apply( $population[, $how_many || $population_size] )

Applies the algorithm to the population, which should have been evaluated first; checks that it receives a ref-to-array as input, croaks if it does not. Returns a sorted, culled, evaluated population for next generation.

It is valid only for string-denominated chromosomes. Checks that the offspring is different from parents before inserting it.

Copyright

  This file is released under the GPL. See the LICENSE file included in this distribution,
  or go to http://www.fsf.org/licenses/gpl.txt
  CVS Info: $Date: 2013/01/07 13:54:20 $ 
  $Header: /media/Backup/Repos/opeal/opeal/Algorithm-Evolutionary/lib/Algorithm/Evolutionary/Op/Breeder_Diverser.pm,v 1.7 2013/01/07 13:54:20 jmerelo Exp $ 
  $Author: jmerelo $ 
  $Revision: 1.7 $