001package net.sf.cpsolver.coursett.criteria;
002
003import java.util.Collection;
004import java.util.Set;
005
006import net.sf.cpsolver.coursett.model.Lecture;
007import net.sf.cpsolver.coursett.model.Placement;
008import net.sf.cpsolver.ifs.perturbations.PerturbationsCounter;
009import net.sf.cpsolver.ifs.solver.Solver;
010import net.sf.cpsolver.ifs.util.DataProperties;
011
012/**
013 * Perturbations. This criterion counts differences (perturbations) between initial and the current
014 * solution. It is based on {@link PerturbationsCounter}.
015 * <br>
016 * 
017 * @version CourseTT 1.2 (University Course Timetabling)<br>
018 *          Copyright (C) 2006 - 2011 Tomáš Müller<br>
019 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
020 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
021 * <br>
022 *          This library is free software; you can redistribute it and/or modify
023 *          it under the terms of the GNU Lesser General Public License as
024 *          published by the Free Software Foundation; either version 3 of the
025 *          License, or (at your option) any later version. <br>
026 * <br>
027 *          This library is distributed in the hope that it will be useful, but
028 *          WITHOUT ANY WARRANTY; without even the implied warranty of
029 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
030 *          Lesser General Public License for more details. <br>
031 * <br>
032 *          You should have received a copy of the GNU Lesser General Public
033 *          License along with this library; if not see
034 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
035 */
036
037public class Perturbations extends TimetablingCriterion {
038    private PerturbationsCounter<Lecture, Placement> iPerturbationsCounter = null;
039    
040    public Perturbations() {
041        iValueUpdateType = ValueUpdateType.NoUpdate;
042    }
043    
044    @Override
045    public String getPlacementSelectionWeightName() {
046        return "Placement.MPP_DeltaInitialAssignmentWeight";
047    }
048
049    @Override
050    public boolean init(Solver<Lecture, Placement> solver) {
051        iPerturbationsCounter = solver.getPerturbationsCounter();
052        return super.init(solver);
053    }
054    
055    @Override
056    public double getWeightDefault(DataProperties config) {
057        return config.getPropertyDouble("Comparator.PerturbationPenaltyWeight", 1.0);
058    }
059    
060    public PerturbationsCounter<Lecture, Placement> getPerturbationsCounter() {
061        return iPerturbationsCounter;
062    }
063
064    @Override
065    public double getValue(Placement value, Set<Placement> conflicts) {
066        return getPerturbationsCounter().getPerturbationPenalty(getModel(), value, conflicts);
067    }
068    
069    @Override
070    public double getValue() {
071        return getPerturbationsCounter().getPerturbationPenalty(getModel());
072    }
073
074    @Override
075    public double getValue(Collection<Lecture> variables) {
076        return getPerturbationsCounter().getPerturbationPenalty(getModel(), variables);
077    }
078
079    @Override
080    public double[] getBounds() {
081        return new double[] { 0.0, 0.0 };
082    }
083    
084    @Override
085    public double[] getBounds(Collection<Lecture> variables) {
086        return new double[] { 0.0, 0.0 };
087    }
088}