net.sourceforge.cilib.moo.archive.constrained.SetBasedConstrainedArchive.java Source code

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Here is the source code for net.sourceforge.cilib.moo.archive.constrained.SetBasedConstrainedArchive.java

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/**
 * Computational Intelligence Library (CIlib)
 * Copyright (C) 2003 - 2010
 * Computational Intelligence Research Group (CIRG@UP)
 * Department of Computer Science
 * University of Pretoria
 * South Africa
 *
 * This library is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library; if not, see <http://www.gnu.org/licenses/>.
 */
package net.sourceforge.cilib.moo.archive.constrained;

import com.google.common.collect.Lists;
import com.google.common.collect.Sets;
import java.util.Collection;
import java.util.List;
import java.util.Set;

import net.sourceforge.cilib.moo.archive.Archive;
import net.sourceforge.cilib.problem.OptimisationSolution;
import net.sourceforge.cilib.util.selection.recipes.RandomSelector;
import net.sourceforge.cilib.util.selection.recipes.Selector;

/**
 * <p>
 * A constrained set-driven {@link Archive} implementation. It makes use of
 * a {@link Selection} to determine which solution from the archive
 * will be selected next for removal if the archive grows larger than the capacity.
 * </p>
 *
 */
public class SetBasedConstrainedArchive extends ConstrainedArchive {

    private Set<OptimisationSolution> solutions;
    private Selector<OptimisationSolution> pruningSelection;

    public SetBasedConstrainedArchive() {
        this.solutions = Sets.newLinkedHashSet();
        this.pruningSelection = new RandomSelector<OptimisationSolution>();
    }

    public SetBasedConstrainedArchive(SetBasedConstrainedArchive copy) {
        super(copy);
        this.solutions = Sets.newLinkedHashSet();
        for (OptimisationSolution solution : copy.solutions) {
            this.solutions.add(solution.getClone());
        }
        this.pruningSelection = copy.pruningSelection;
    }

    public void setPruningSelection(Selector<OptimisationSolution> pruningSelection) {
        this.pruningSelection = pruningSelection;
    }

    public Selector<OptimisationSolution> getPruningSelection() {
        return this.pruningSelection;
    }

    @Override
    public boolean dominates(OptimisationSolution candidateSolution) {
        for (OptimisationSolution archiveSolution : this.solutions) {
            if (archiveSolution.compareTo(candidateSolution) > 0) {
                return true;
            }
        }
        return false;
    }

    @Override
    public boolean isDominatedBy(OptimisationSolution candidateSolution) {
        for (OptimisationSolution archiveSolution : this.solutions) {
            if (candidateSolution.compareTo(archiveSolution) > 0) {
                return true;
            }
        }
        return false;
    }

    @Override
    public Collection<OptimisationSolution> getDominant(OptimisationSolution candidateSolution) {
        List<OptimisationSolution> dominantSolutions = Lists.newLinkedList();
        for (OptimisationSolution archiveSolution : this.solutions) {
            if (archiveSolution.compareTo(candidateSolution) > 0) {
                dominantSolutions.add(archiveSolution);
            }
        }
        return dominantSolutions;
    }

    @Override
    public Collection<OptimisationSolution> getDominated(OptimisationSolution candidateSolution) {
        List<OptimisationSolution> dominatedSolutions = Lists.newLinkedList();
        for (OptimisationSolution archiveSolution : this.solutions) {
            if (candidateSolution.compareTo(archiveSolution) > 0) {
                dominatedSolutions.add(archiveSolution);
            }
        }
        return dominatedSolutions;
    }

    @Override
    protected void prune() {
        // If the archive size is greater than the capacity, select a group of solutions and remove them from the archive.
        int numSolutionsToRemove = size() - getCapacity();
        for (int i = 0; i < numSolutionsToRemove; ++i) {
            OptimisationSolution solutionToRemove = this.pruningSelection.on(this).select();
            remove(solutionToRemove);
        }
    }

    @Override
    public boolean addToStructure(OptimisationSolution optimisationSolution) {
        return this.solutions.add(optimisationSolution);
    }

    @Override
    protected Collection<OptimisationSolution> delegate() {
        return this.solutions;
    }
}