org.jgap.impl
Class AveragingCrossoverOperator

java.lang.Object
  org.jgap.BaseGeneticOperator
      org.jgap.impl.AveragingCrossoverOperator

All Implemented Interfaces:

java.io.Serializable, java.lang.Comparable, GeneticOperator

public class AveragingCrossoverOperator
extends BaseGeneticOperator

The averaging crossover operator randomly selects two Chromosomes from the population and "mates" them by randomly picking a gene and then swapping that gene and all subsequent genes between the two Chromosomes. The two modified Chromosomes are then added to the list of candidate Chromosomes. This operation is performed half as many times as there are Chromosomes in the population. Additionally, the loci of crossing over are cached for each index, i.e., after randomizing the loci for each index once, they don't change again. If you work with CompositeGene's, this operator expects them to contain genes of the same type (e.g. IntegerGene). If you have mixed types, please provide your own crossover operator.

Since:

2.0

See Also:

Serialized Form

Field Summary

Fields inherited from class org.jgap.BaseGeneticOperator

m_monitor, m_monitorActive

Constructor Summary

AveragingCrossoverOperator()
Using the same random generator for randomizing the loci for crossing over as for selecting the genes to be crossed over.

AveragingCrossoverOperator(Configuration a_configuration)
Using the same random generator for randomizing the loci for crossing over as for selecting the genes to be crossed over.

AveragingCrossoverOperator(Configuration a_configuration, IUniversalRateCalculator a_crossoverRateCalculator)
Constructs a new instance of this CrossoverOperator with a specified crossover rate calculator, which results in dynamic crossover being turned on.

AveragingCrossoverOperator(Configuration a_configuration, RandomGenerator a_generatorForAveraging)
Using a different random generator for randomizing the loci for crossing over than for selecting the genes to be crossed over

Method Summary

int	compareTo(java.lang.Object a_other) Compares the given object to this one.
boolean	equals(java.lang.Object a_other) Compares this GeneticOperator against the specified object.
protected int	getLocus(RandomGenerator a_generator, int a_index, int a_max) Returns the crossover location for a given index.
void	operate(Population a_population, java.util.List a_candidateChromosomes) Crossover that acts as a perturbed mean of two individuals.
void	setCrossoverRate(int a_rate)

Methods inherited from class org.jgap.BaseGeneticOperator

getConfiguration

Methods inherited from class java.lang.Object

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

Constructor Detail

AveragingCrossoverOperator

public AveragingCrossoverOperator()
                           throws InvalidConfigurationException

Using the same random generator for randomizing the loci for crossing over as for selecting the genes to be crossed over.

Attention: The configuration used is the one set with the static method Genotype.setConfiguration.

Throws:

InvalidConfigurationException

Since:

2.0

AveragingCrossoverOperator

public AveragingCrossoverOperator(Configuration a_configuration)
                           throws InvalidConfigurationException

Using the same random generator for randomizing the loci for crossing over as for selecting the genes to be crossed over.

Parameters:

a_configuration - the configuration to use

Throws:

InvalidConfigurationException

Since:

3.0

AveragingCrossoverOperator

public AveragingCrossoverOperator(Configuration a_configuration,
                                  RandomGenerator a_generatorForAveraging)
                           throws InvalidConfigurationException

Using a different random generator for randomizing the loci for crossing over than for selecting the genes to be crossed over

Parameters:

a_configuration - the configuration to use

a_generatorForAveraging - RandomGenerator to use

Throws:

InvalidConfigurationException

Since:

3.0 (since 2.0 without a_configuration)

AveragingCrossoverOperator

public AveragingCrossoverOperator(Configuration a_configuration,
                                  IUniversalRateCalculator a_crossoverRateCalculator)
                           throws InvalidConfigurationException

Constructs a new instance of this CrossoverOperator with a specified crossover rate calculator, which results in dynamic crossover being turned on.

Parameters:

a_configuration - the configuration to use

a_crossoverRateCalculator - calculator for dynamic crossover rate computation

Throws:

InvalidConfigurationException

Since:

3.0 (since 2.0 without a_configuration)

Method Detail

operate

public void operate(Population a_population,
                    java.util.List a_candidateChromosomes)

Crossover that acts as a perturbed mean of two individuals. x_i = p*x1_i + (1-p)*x2_i p - uniform random value over [0,1]. Averaging over line means p is same for every i, averaging over space if different p is chosen for each i. See CrossoverOperator for general description, also see feature request 708774

Parameters:

a_population - Chromosome[]

a_candidateChromosomes - List

Since:

2.0

getLocus

protected int getLocus(RandomGenerator a_generator,
                       int a_index,
                       int a_max)

Returns the crossover location for a given index. For each index the crossover locatio is the same, therefor it is cached!

Parameters:

a_generator - to generate random values the first time

a_index - the index of the crossover operation

a_max - upper boundary for random generator

Returns:

crossover location for a given index

Since:

2.0

equals

public boolean equals(java.lang.Object a_other)

Compares this GeneticOperator against the specified object. The result is true if and the argument is an instance of this class and is equal wrt the data.

Overrides:

equals in class BaseGeneticOperator

Parameters:

a_other - the object to compare against

Returns:

true: if the objects are the same, false otherwise

Since:

2.6

compareTo

public int compareTo(java.lang.Object a_other)

Compares the given object to this one.

Parameters:

a_other - the instance against which to compare this instance

Returns:

a negative number if this instance is "less than" the given instance, zero if they are equal to each other, and a positive number if this is "greater than" the given instance

Since:

2.6

setCrossoverRate

public void setCrossoverRate(int a_rate)

Parameters:

a_rate - crossover rate to use by this crossover operator

Since:

2.6