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    }