org.uncommons.watchmaker.framework.operators
Class ObjectArrayCrossover<T>

java.lang.Object
  org.uncommons.watchmaker.framework.operators.AbstractCrossover<T[]>
      org.uncommons.watchmaker.framework.operators.ObjectArrayCrossover<T>

Type Parameters:

T - The component type of the arrays that are being evolved.

All Implemented Interfaces:

EvolutionaryOperator<T[]>

public class ObjectArrayCrossover<T>
extends AbstractCrossover<T[]>

Cross-over with a configurable number of points (fixed or random) for arrays of reference types.

Author:

Daniel Dyer

Constructor Summary

ObjectArrayCrossover()
Default is single-point cross-over, applied to all parents.

ObjectArrayCrossover(int crossoverPoints)
Cross-over with a fixed number of cross-over points.

ObjectArrayCrossover(int crossoverPoints, Probability crossoverProbability)
Cross-over with a fixed number of cross-over points.

ObjectArrayCrossover(NumberGenerator<Integer> crossoverPointsVariable)
Cross-over with a variable number of cross-over points.

ObjectArrayCrossover(NumberGenerator<Integer> crossoverPointsVariable, NumberGenerator<Probability> crossoverProbabilityVariable)
Sets up a cross-over implementation that uses a variable number of cross-over points.

Method Summary

protected List<T[]>

mate(T[] parent1, T[] parent2, int numberOfCrossoverPoints, Random rng) Perform cross-over on a pair of parents to generate a pair of offspring.

Methods inherited from class org.uncommons.watchmaker.framework.operators.AbstractCrossover

apply

Methods inherited from class java.lang.Object

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

Constructor Detail

ObjectArrayCrossover

public ObjectArrayCrossover()

Default is single-point cross-over, applied to all parents.

ObjectArrayCrossover

public ObjectArrayCrossover(int crossoverPoints)

Cross-over with a fixed number of cross-over points.

Parameters:

crossoverPoints - The constant number of cross-over points to use for all cross-over operations.

ObjectArrayCrossover

public ObjectArrayCrossover(int crossoverPoints,
                            Probability crossoverProbability)

Cross-over with a fixed number of cross-over points. Cross-over may or may not be applied to a given pair of parents depending on the crossoverProbability.

Parameters:

crossoverPoints - The constant number of cross-over points to use for all cross-over operations.

crossoverProbability - The probability that, once selected, a pair of parents will be subjected to cross-over rather than being copied, unchanged, into the output population.

ObjectArrayCrossover

public ObjectArrayCrossover(NumberGenerator<Integer> crossoverPointsVariable)

Cross-over with a variable number of cross-over points.

Parameters:

crossoverPointsVariable - A random variable that provides a number of cross-over points for each cross-over operation.

ObjectArrayCrossover

public ObjectArrayCrossover(NumberGenerator<Integer> crossoverPointsVariable,
                            NumberGenerator<Probability> crossoverProbabilityVariable)

Sets up a cross-over implementation that uses a variable number of cross-over points. Cross-over is applied to a proportion of selected parent pairs, with the remainder copied unchanged into the output population. The size of this evolved proportion is controlled by the crossoverProbabilityVariable parameter.

Parameters:

crossoverPointsVariable - A variable that provides a (possibly constant, possibly random) number of cross-over points for each cross-over operation.

crossoverProbabilityVariable - A variable that controls the probability that, once selected, a pair of parents will be subjected to cross-over rather than being copied, unchanged, into the output population.

Method Detail

mate

protected List<T[]> mate(T[] parent1,
                         T[] parent2,
                         int numberOfCrossoverPoints,
                         Random rng)

Perform cross-over on a pair of parents to generate a pair of offspring.

Specified by:

mate in class AbstractCrossover<T[]>

Parameters:

parent1 - One of two individuals that provides the source material for generating offspring.

parent2 - One of two individuals that provides the source material for generating offspring.

numberOfCrossoverPoints - The number of cross-overs performed on the two parents.

rng - A source of randomness used to determine the location of cross-over points.

Returns:

A list containing two evolved offspring.