    001package org.cpsolver.coursett.criteria;
    002
    003import java.util.Collection;
    004import java.util.Set;
    005
    006import org.cpsolver.coursett.model.Lecture;
    007import org.cpsolver.coursett.model.Placement;
    008import org.cpsolver.ifs.assignment.Assignment;
    009import org.cpsolver.ifs.perturbations.PerturbationsCounter;
    010import org.cpsolver.ifs.solver.Solver;
    011import org.cpsolver.ifs.util.DataProperties;
    012
    013
    014/**
    015 * Perturbations. This criterion counts differences (perturbations) between initial and the current
    016 * solution. It is based on {@link PerturbationsCounter}.
    017 * <br>
    018 *
    019 * @author  Tomáš Müller
    020 * @version CourseTT 1.3 (University Course Timetabling)<br>
    021 *          Copyright (C) 2006 - 2014 Tomáš Müller<br>
    022 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
    023 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
    024 * <br>
    025 *          This library is free software; you can redistribute it and/or modify
    026 *          it under the terms of the GNU Lesser General Public License as
    027 *          published by the Free Software Foundation; either version 3 of the
    028 *          License, or (at your option) any later version. <br>
    029 * <br>
    030 *          This library is distributed in the hope that it will be useful, but
    031 *          WITHOUT ANY WARRANTY; without even the implied warranty of
    032 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
    033 *          Lesser General Public License for more details. <br>
    034 * <br>
    035 *          You should have received a copy of the GNU Lesser General Public
    036 *          License along with this library; if not see
    037 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
    038 */
    039
    040public class Perturbations extends TimetablingCriterion {
    041    private PerturbationsCounter<Lecture, Placement> iPerturbationsCounter = null;
    042
    043    public Perturbations() {
    044        setValueUpdateType(ValueUpdateType.NoUpdate);
    045    }
    046
    047    @Override
    048    public String getPlacementSelectionWeightName() {
    049        return "Placement.MPP_DeltaInitialAssignmentWeight";
    050    }
    051
    052    @Override
    053    public boolean init(Solver<Lecture, Placement> solver) {
    054        iPerturbationsCounter = solver.getPerturbationsCounter();
    055        return super.init(solver);
    056    }
    057
    058    @Override
    059    public double getWeightDefault(DataProperties config) {
    060        return config.getPropertyDouble("Comparator.PerturbationPenaltyWeight", 1.0);
    061    }
    062
    063    public PerturbationsCounter<Lecture, Placement> getPerturbationsCounter() {
    064        return iPerturbationsCounter;
    065    }
    066
    067    @Override
    068    public double getValue(Assignment<Lecture, Placement> assignment, Placement value, Set<Placement> conflicts) {
    069        return getPerturbationsCounter().getPerturbationPenalty(assignment, getModel(), value, conflicts);
    070    }
    071
    072    @Override
    073    public double getValue(Assignment<Lecture, Placement> assignment) {
    074        return getPerturbationsCounter().getPerturbationPenalty(assignment, getModel());
    075    }
    076
    077    @Override
    078    public double getValue(Assignment<Lecture, Placement> assignment, Collection<Lecture> variables) {
    079        return getPerturbationsCounter().getPerturbationPenalty(assignment, getModel(), variables);
    080    }
    081
    082    @Override
    083    public double[] getBounds(Assignment<Lecture, Placement> assignment) {
    084        return new double[] { 0.0, 0.0 };
    085    }
    086
    087    @Override
    088    public double[] getBounds(Assignment<Lecture, Placement> assignment, Collection<Lecture> variables) {
    089        return new double[] { 0.0, 0.0 };
    090    }
    091}