Package net.bmahe.genetics4j.gp.mutation

Class NodeReplacementMutator

java.lang.Object

net.bmahe.genetics4j.gp.mutation.NodeReplacementMutator

All Implemented Interfaces:

Mutator

public class NodeReplacementMutator
extends Object
implements Mutator

Field Summary

Fields

Modifier and Type	Field	Description
private final AbstractEAConfiguration	eaConfiguration
private final double	populationMutationProbability
private final ProgramHelper	programHelper
private final RandomGenerator	randomGenerator

Constructor Summary

Constructors

Constructor	Description
NodeReplacementMutator(ProgramHelper _programHelper, RandomGenerator _randomGenerator, AbstractEAConfiguration _eaConfiguration, double populationMutationProbability)

Method Summary

Modifier and Type	Method	Description
protected TreeNode<Operation<?>>	duplicateAndReplaceNode(Program program, TreeNode<Operation<?>> root, int cutPoint, int nodeIndex)
protected TreeNode<Operation<?>>	duplicateNode(Program program, TreeNode<Operation<?>> root, int cutPoint, int nodeIndex)
protected List<OperationFactory>	findReplacementCandidates(Program program, TreeNode<Operation<?>> root)
Genotype	mutate(Genotype original)	Applies mutation to the given genotype and returns a new mutated genotype.

Methods inherited from class java.lang.Object

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

Field Details

programHelper

private final ProgramHelper programHelper

randomGenerator

private final RandomGenerator randomGenerator

eaConfiguration

private final AbstractEAConfiguration eaConfiguration

populationMutationProbability

private final double populationMutationProbability

Constructor Details

NodeReplacementMutator

public NodeReplacementMutator(ProgramHelper _programHelper,
 RandomGenerator _randomGenerator,
 AbstractEAConfiguration _eaConfiguration,
 double populationMutationProbability)

Method Details

duplicateNode

protected TreeNode<Operation<?>> duplicateNode(Program program,
 TreeNode<Operation<?>> root,
 int cutPoint,
 int nodeIndex)

findReplacementCandidates

protected List<OperationFactory> findReplacementCandidates(Program program,
 TreeNode<Operation<?>> root)

duplicateAndReplaceNode

protected TreeNode<Operation<?>> duplicateAndReplaceNode(Program program,
 TreeNode<Operation<?>> root,
 int cutPoint,
 int nodeIndex)

mutate

public Genotype mutate(Genotype original)

Description copied from interface: Mutator

Applies mutation to the given genotype and returns a new mutated genotype.

The original genotype should not be modified; instead, a new genotype with the mutations applied should be returned. The specific mutation behavior depends on the implementation and the mutation policy being used.

Mutation may affect:

• Individual alleles within chromosomes (bit flips, value changes)
• Chromosome structure (for variable-length representations)
• Multiple chromosomes simultaneously

Specified by:

mutate in interface Mutator

Parameters:

original - the genotype to mutate, must not be null

Returns:

a new genotype with mutations applied, never null