org.opt4j.operator.crossover

Class CrossoverDoubleBLX

java.lang.Object

org.opt4j.operator.crossover.CrossoverDouble

org.opt4j.operator.crossover.CrossoverDoubleElementwise

org.opt4j.operator.crossover.CrossoverDoubleBLX

All Implemented Interfaces:

Operator<DoubleGenotype>, Crossover<DoubleGenotype>

public class CrossoverDoubleBLX
extends CrossoverDoubleElementwise

The CrossoverDoubleBLX is an implementation of the blend crossover operator proposed by Eshelman and Schaffer, 1993.

The BLX crossover is applied element-wise. For two double values y and x (assuming y > x one offspring value is created in the uniform interval [x-(y-x)*alpha;y+(y-x)*alpha].

If alpha is set to 0, the operator creates a random solution between x and y. Values greater zero allow offspring that is apart from the interval between x and y. The authors report best performance with alpha = 0.5 which is then called the BLX-0.5 operator.

Author:

glass, lukasiewycz

Constructor Summary

Constructors

Constructor and Description
CrossoverDoubleBLX(double alpha, NormalizeDouble normalize, Rand random) Constructs a CrossoverDoubleBLX with an alpha value, an NormalizeDouble operator, and a random number generator.

Method Summary

Modifier and Type	Method and Description
Pair<Double>	crossover(double x, double y) Performs a crossover with two double values.

Methods inherited from class org.opt4j.operator.crossover.CrossoverDouble

crossover

Methods inherited from class java.lang.Object

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

Constructor Detail

CrossoverDoubleBLX

@Inject
public CrossoverDoubleBLX(double alpha,
                                  NormalizeDouble normalize,
                                  Rand random)

Constructs a CrossoverDoubleBLX with an alpha value, an NormalizeDouble operator, and a random number generator.

Parameters:

alpha - the alpha value

normalize - the normalize operator

random - the random number generator

Method Detail

crossover

public Pair<Double> crossover(double x,
                              double y)

Description copied from class: CrossoverDoubleElementwise

Performs a crossover with two double values.

Specified by:

crossover in class CrossoverDoubleElementwise

Parameters:

x - the first value

y - the second value

Returns:

the resulting values