org.jenetics.ext

Class SimulatedBinaryCrossover<G extends NumericGene<?,G>,C extends Comparable<? super C>>

java.lang.Object

org.jenetics.AbstractAlterer<G,C>

org.jenetics.Recombinator<G,C>

org.jenetics.Crossover<G,C>

org.jenetics.ext.SimulatedBinaryCrossover<G,C>

All Implemented Interfaces:

Alterer<G,C>

public class SimulatedBinaryCrossover<G extends NumericGene<?,G>,C extends Comparable<? super C>>
extends Crossover<G,C>

Performs the simulated binary crossover (SBX) on a Chromosome of NumericGenes such that each position is either crossed contracted or expanded with a certain probability. The probability distribution is designed such that the children will lie closer to their parents as is the case with the single point binary crossover.

It is implemented as described in Deb, K. and Agrawal, R. B. 1995. Simulated binary crossover for continuous search space. Complex Systems, 9, pp. 115-148.

Since:

3.5

Version:

3.5

Author:

Franz Wilhelmstötter

Field Summary

Fields inherited from class org.jenetics.AbstractAlterer

_probability

Fields inherited from interface org.jenetics.Alterer

DEFAULT_ALTER_PROBABILITY

Constructor Summary

Constructors

Constructor and Description
SimulatedBinaryCrossover(double probability) Create a new simulated binary crossover alterer with the given parameters.
SimulatedBinaryCrossover(double probability, double contiguity) Create a new simulated binary crossover alterer with the given parameters.

Method Summary

Modifier and Type	Method and Description
protected int	crossover(MSeq<G> that, MSeq<G> other)
double	getContiguity() Return the contiguity value of the crossover.

Methods inherited from class org.jenetics.Crossover

recombine

Methods inherited from class org.jenetics.Recombinator

alter, getOrder

Methods inherited from class org.jenetics.AbstractAlterer

equals, getProbability, hashCode

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.jenetics.Alterer

andThen, compose, of

Constructor Detail

SimulatedBinaryCrossover

public SimulatedBinaryCrossover(double probability,
                                double contiguity)

Create a new simulated binary crossover alterer with the given parameters.

Parameters:

probability - the recombination probability

contiguity - the contiguity value that specifies how close a child should be to its parents (larger value means closer). The value must be greater or equal than 0. Typical values are in the range [2..5].

Throws:

IllegalArgumentException - if the probability is not in the valid range of [0, 1]

IllegalArgumentException - if contiguity is smaller than zero

SimulatedBinaryCrossover

public SimulatedBinaryCrossover(double probability)

Create a new simulated binary crossover alterer with the given parameters. The contiguity value is set to 2.5.

Parameters:

probability - the recombination probability

Throws:

IllegalArgumentException - if the probability is not in the valid range of [0, 1]

IllegalArgumentException - if contiguity is smaller than zero

Method Detail

getContiguity

public double getContiguity()

Return the contiguity value of the crossover.

Returns:

the contiguity value of the crossover

crossover

protected int crossover(MSeq<G> that,
                        MSeq<G> other)

Specified by:

crossover in class Crossover<G extends NumericGene<?,G>,C extends Comparable<? super C>>