Package org.moeaframework.core.operator.program

Class SubtreeCrossover

java.lang.Object

org.moeaframework.core.operator.TypeSafeCrossover<Program>

org.moeaframework.core.operator.program.SubtreeCrossover

All Implemented Interfaces:

Configurable, Named, Variation

public class SubtreeCrossover
extends TypeSafeCrossover<Program>

Exchanges a randomly-selected subtree from one program with a compatible, randomly-selected subtree from another program.

This operator is type-safe.

Constructor Summary

Constructors

Constructor	Description
SubtreeCrossover()	Constructs a new subtree crossover instance with a 90% chance of being applied to each solution.
SubtreeCrossover(double probability)	Constructs a new subtree crossover instance.

Method Summary

Modifier and Type	Method	Description
Solution[]	evolve(Solution[] parents)	Evolves one or more parent solutions (specified by getArity) and produces one or more child solutions.
void	evolve(Program program1, Program program2)	Applies subtree crossover to the programs.
String	getName()	Returns the name of this variation operator.

Methods inherited from class org.moeaframework.core.operator.TypeSafeCrossover

getArity, getProbability, setProbability

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.moeaframework.core.configuration.Configurable

applyConfiguration, getConfiguration

Constructor Details

SubtreeCrossover

public SubtreeCrossover()

Constructs a new subtree crossover instance with a 90% chance of being applied to each solution.

SubtreeCrossover

public SubtreeCrossover(double probability)

Constructs a new subtree crossover instance.

Parameters:

probability - the probability that subtree crossover is applied to a program

Method Details

getName

public String getName()

Description copied from interface: Variation

Returns the name of this variation operator. This name should also be used as the prefix for any parameters. As such, the name should only contain alphanumeric characters, avoid using whitespace and other symbols.

Returns:

the name of this variation operator

evolve

public Solution[] evolve(Solution[] parents)

Description copied from interface: Variation

Evolves one or more parent solutions (specified by getArity) and produces one or more child solutions. By contract, the parents must not be modified. The copy constructor should be used to create copies of the parents with these copies subsequently modified.

Specified by:

evolve in interface Variation

Overrides:

evolve in class TypeSafeCrossover<Program>

Parameters:

parents - the array of parent solutions

Returns:

an array of child solutions

evolve

public void evolve(Program program1,
 Program program2)

Applies subtree crossover to the programs.

Specified by:

evolve in class TypeSafeCrossover<Program>

Parameters:

program1 - the first program, which is the parent program

program2 - the second program, which provides the replacement subtree