view release on metacpan or  search on metacpan

lib/Algorithm/Evolutionary/Op/FullAlgorithm.pm  view on Meta::CPAN

  $f->apply( $pop ); # Pop should be defined else where

=head1 Base Class

L<Algorithm::Evolutionary::Op::Base>

=head1 DESCRIPTION

Class for a configurable evolutionary algoritm. It takes a
single-generarion object, and mixes it with a termination condition
to create a full algorithm. Includes a sensible default
(100-generation generational algorithm) if it is issued only an object
of class L<Algorithm::Evolutionary::Op::GeneralGeneration>.

=cut

package Algorithm::Evolutionary::Op::FullAlgorithm;

our ($VERSION) = ( '$Revision: 3.0 $ ' =~ / (\d+\.\d+)/ ) ;

use Carp;

use base 'Algorithm::Evolutionary::Op::Base';

#  Class-wide constants
our $APPLIESTO =  'ARRAY';
our $ARITY = 1;

=head2 new( $single_generation[, $termination_test] [, $verboseness] )

Takes an already created algorithm and a terminator, and creates an object

=cut

sub new {
  my $class = shift;
  my $algo = shift|| croak "No single generation algorithm found";
  my $term = shift ||  new  Algorithm::Evolutionary::Op::GenerationalTerm 100;
  my $verbose = shift || 0;
  my $hash = { algo => $algo,
	       terminator => $term,
	       verbose => $verbose };
  my $self = Algorithm::Evolutionary::Op::Base::new( __PACKAGE__, 1, $hash );
  return $self;
}

=head2 set( $hashref, $codehash, $opshash )

Sets the instance variables. Takes hashes to the different options of
    the algorithm: parameters, fitness functions and operators

=cut

sub set {
  my $self = shift;
  my $hashref = shift || croak "No params here";
  my $codehash = shift;
  my $opshash = shift;

  $self->SUPER::set( $hashref ); # Base class only aware of options
  #Now reconstruct operators
  for my $o ( keys %$opshash ) { #ops are keyed by type
	$self->{$opshash->{$o}->[1]->{'-id'}} = 
	  Algorithm::Evolutionary::Op::Base::fromXML( $o, $opshash->{$o}->[1], $opshash->{$o}->[0] ); 
  }

}

=head2 apply( $reference_to_population_array )

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

=cut

sub apply ($) {
  my $self = shift;
  my $pop = shift || croak "No population here";
  croak "Incorrect type ".(ref $pop) if  ref( $pop ) ne $APPLIESTO;

  my $term = $self->{_terminator};
  my $algo = $self->{_algo};
  #Evaluate population, just in case
  my $eval = $algo->{_eval};
  for ( @$pop ) {
    if ( !defined $_->Fitness() ) {
      $_->evaluate( $eval );
    }
  }
  #Run the algorithm
  do {
    $algo->apply( $pop );
    if  ($self->{_verbose}) {
      print "Best ", $pop->[0]->asString(), "\n" ;
      print "Median ", $pop->[@$pop/2]->asString(), "\n";
      print "Worst ", $pop->[@$pop-1]->asString(), "\n\n";
    }
  } while( $term->apply( $pop ) );
  
}

=head1 SEE ALSO

More or less in the same ballpark, alternatives to this one

=over 4

=item * 

L<Algorithm::Evolutionary::Op::CanonicalGA>.

=item *

L<Algorithm::Evolutionary::Op::Easy>.

=back 

Classes you can use within FullAlgorithm: