edu.udo.cs.yale.operator.features.selection
Class TournamentSelection

java.lang.Object
  edu.udo.cs.yale.operator.features.selection.TournamentSelection

All Implemented Interfaces:

PopulationOperator

public class TournamentSelection
extends java.lang.Object
implements PopulationOperator

Performs tournaments with k participants. The winner of each tournament is added to the next population. This will be repeated until the desired population size is reached. The tournament size k represents the selection pressure. For small sizes (like 2) relatively bad individuals have a good chance to survive. If k reaches the population size, only the best individual will survive.

Version:

$Id: TournamentSelection.java,v 1.1 2006/04/14 07:47:17 ingomierswa Exp $

Author:

Ingo Mierswa

Field Summary

private double	delta
private boolean	keepBest
private int	popSize
private java.util.Random	random
private double	tournamentFraction

Constructor Summary

TournamentSelection(int popSize, double tournamentFraction, int maxGenerations, boolean dynamic, boolean keepBest, java.util.Random random)

Method Summary

void	operate(Population population) Modifies the population.
boolean	performOperation(int generation) Indicates if the operation should be performed in the given generation.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

popSize

private int popSize

tournamentFraction

private double tournamentFraction

delta

private double delta

keepBest

private boolean keepBest

random

private java.util.Random random

Constructor Detail

TournamentSelection

public TournamentSelection(int popSize,
                           double tournamentFraction,
                           int maxGenerations,
                           boolean dynamic,
                           boolean keepBest,
                           java.util.Random random)

Method Detail

performOperation

public boolean performOperation(int generation)

Description copied from interface: PopulationOperator

Indicates if the operation should be performed in the given generation. Allows pop ops which works only in a part of the generations.

Specified by:

performOperation in interface PopulationOperator

operate

public void operate(Population population)

Description copied from interface: PopulationOperator

Modifies the population.

Specified by:

operate in interface PopulationOperator