classifier.gp
Class CrossoverPlain

java.lang.Object
  classifier.gp.CrossoverPlain

All Implemented Interfaces:

CrossoverOperator, Operators, java.io.Serializable

public class CrossoverPlain

extends java.lang.Object

implements CrossoverOperator

Implementation of the classical crossover operator

Version:

0.1

Author:

Sacchi Matteo, Sassi Federico

See Also:

Serialized Form

Field Summary

protected double	external
protected GProgram	female
protected double	internal
protected GProgram	male
protected int	max_depth

Constructor Summary

CrossoverPlain(int max_depth, double internal, boolean keep)
Inizialize the parameters of the crossover

Method Summary

double	getExternaleRate() Probability that a external node is chosen as a crossover point
double	getInternalRate() Probability that a internal node is chosen as a crossover point
int	getMaxDepth() Maximum allowable depth of the resulting tree
void	setExternalRate(double external) To change the probability that a external node is chosen as a crossover point
void	setInternalRate(double internal) To change the probability that a internal node is chosen as a crossover point
void	setMaxDetph(int max) To change the maximum allowable depth of a tree
GProgram[]	start(GProgram[] programs) Method to start the crossover operation
(package private) void	validateCrossover(GProgram male, GProgram female, GProgram[] offspring) To check if the result of a crossover is valid, if it's not and keep==true then the crossover operation will be repeated recursively

Methods inherited from class java.lang.Object

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

Field Detail

male

protected GProgram male

female

protected GProgram female

max_depth

protected int max_depth

internal

protected double internal

external

protected double external

Constructor Detail

CrossoverPlain

public CrossoverPlain(int max_depth,
                      double internal,
                      boolean keep)

Inizialize the parameters of the crossover

Parameters:

max_depth - Maximum allowable depth of the resulting tree

internal - Probability [0..1] that a internal node is chosen as a crossover point

keep - if it is true the crossover will be repeated until a pair of valid children in found

Method Detail

getMaxDepth

public int getMaxDepth()

Maximum allowable depth of the resulting tree

Returns:

An integer that correspond to the maximum allowable depth of a tree

getInternalRate

public double getInternalRate()

Probability that a internal node is chosen as a crossover point

Returns:

The probability as a double in the range [0..1]

getExternaleRate

public double getExternaleRate()

Probability that a external node is chosen as a crossover point

Returns:

The probability as a double in the range [0..1]

setMaxDetph

public void setMaxDetph(int max)

To change the maximum allowable depth of a tree

Parameters:

max - new integer value of the maximum depth

setInternalRate

public void setInternalRate(double internal)

To change the probability that a internal node is chosen as a crossover point

Parameters:

internal - a double value in the range of [0..1]

setExternalRate

public void setExternalRate(double external)

To change the probability that a external node is chosen as a crossover point

Parameters:

external - a double value in the range of [0..1]

start

public GProgram[] start(GProgram[] programs)

Method to start the crossover operation

Specified by:

start in interface CrossoverOperator

Parameters:

programs - Array of 2 GProgram containing the parents

Returns:

Array of 2 GProgram containing the result of the crossover

validateCrossover

void validateCrossover(GProgram male,
                       GProgram female,
                       GProgram[] offspring)

To check if the result of a crossover is valid, if it's not and keep==true then the crossover operation will be repeated recursively

Parameters:

male - a parent

female - the other parent

offspring - array of 2 GProgram that contain the offspring that have to be checked