001 package net.sf.cpsolver.coursett.criteria;
002
003 import java.util.Collection;
004 import java.util.Set;
005
006 import net.sf.cpsolver.coursett.model.Lecture;
007 import net.sf.cpsolver.coursett.model.Placement;
008 import net.sf.cpsolver.ifs.perturbations.PerturbationsCounter;
009 import net.sf.cpsolver.ifs.solver.Solver;
010 import 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 Tomas Muller<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
037 public 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 }