net.sourceforge.cilib.pso.pbestupdate.BoundedNonDominatedPersonalBestUpdateStrategy Maven / Gradle / Ivy

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A library of composable components enabling simpler Computational Intelligence

There is a newer version: 0.8

/**           __  __
 *    _____ _/ /_/ /_    Computational Intelligence Library (CIlib)
 *   / ___/ / / / __ \   (c) CIRG @ UP
 *  / /__/ / / / /_/ /   http://cilib.net
 *  \___/_/_/_/_.___/
 */
package net.sourceforge.cilib.pso.pbestupdate;

import net.sourceforge.cilib.entity.EntityType;
import net.sourceforge.cilib.pso.particle.Particle;
import net.sourceforge.cilib.problem.solution.InferiorFitness;
import net.sourceforge.cilib.type.types.Types;

/**
 * 
 * Implementation of {@link GuideUpdateStrategy} where a particle's guide
 * can get updated if the new guide is not dominated by the current guide,
 * i.e. both of the guides are non-dominated. If both guides are non-
 * dominated the new guide is selected.
 * 
 *
 *
 */
public class BoundedNonDominatedPersonalBestUpdateStrategy extends NonDominatedPersonalBestUpdateStrategy {

   /**
    * {@inheritDoc}
    */
    @Override
    public PersonalBestUpdateStrategy getClone() {
        return this;
    }

    /**
     * If the current fitness is better than the best fitness, or both are
     * non-dominated, update the best fitness to the current fitness.
     *
     * If the current fitness is not updated, increase the particle's pbest stagnation counter.
     * @param particle The particle to update.
     */
    @Override
    public void updatePersonalBest(Particle particle) {
        if (!Types.isInsideBounds(particle.getPosition())) {
            particle.getProperties().put(EntityType.FITNESS, InferiorFitness.instance());
            return;
        }

        super.updatePersonalBest(particle);
    }

}