Package org.moeaframework.algorithm

Class SPEA2.StrengthFitnessEvaluator

java.lang.Object

org.moeaframework.algorithm.SPEA2.StrengthFitnessEvaluator

All Implemented Interfaces:

Configurable, FitnessEvaluator

Enclosing class:

SPEA2

public class SPEA2.StrengthFitnessEvaluator
extends Object
implements FitnessEvaluator, Configurable

Fitness evaluator for the strength measure with crowding-based niching.

Field Summary

Fields inherited from interface org.moeaframework.core.FitnessEvaluator

FITNESS_ATTRIBUTE

Constructor Summary

Constructors

Constructor	Description
StrengthFitnessEvaluator(int k)	Constructs a new fitness evaluator for computing the strength measure with crowding-based niching.

Method Summary

Modifier and Type	Method	Description
boolean	areLargerValuesPreferred()	Returns true if larger fitness values are preferred; otherwise smaller fitness values are preferred.
void	evaluate(Population population)	Evaluates the solutions in the specified population assigning the FITNESS_ATTRIBUTE attribute.
int	getK()	Returns the value k that controls which nearest neighbor is used to compute the crowding distance.
void	setK(int k)	Sets the value k that controls which nearest neighbor is used to compute the crowding distance.

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

StrengthFitnessEvaluator

public StrengthFitnessEvaluator(int k)

Constructs a new fitness evaluator for computing the strength measure with crowding-based niching.

Parameters:

k - crowding is based on the distance to the k-th nearest neighbor

Method Details

getK

public int getK()

Returns the value k that controls which nearest neighbor is used to compute the crowding distance.

Returns:

the value k

setK

public void setK(int k)

Sets the value k that controls which nearest neighbor is used to compute the crowding distance. This is set to 1 by default.

Parameters:

k - the value k

evaluate

public void evaluate(Population population)

Description copied from interface: FitnessEvaluator

Evaluates the solutions in the specified population assigning the FITNESS_ATTRIBUTE attribute.

Specified by:

evaluate in interface FitnessEvaluator

Parameters:

population - the population to be evaluated

areLargerValuesPreferred

public boolean areLargerValuesPreferred()

Description copied from interface: FitnessEvaluator

Returns true if larger fitness values are preferred; otherwise smaller fitness values are preferred.

Specified by:

areLargerValuesPreferred in interface FitnessEvaluator

Returns:

true if larger fitness values are preferred; otherwise smaller fitness values are preferred