001package org.cpsolver.coursett.criteria;
002
003import java.util.Collection;
004import java.util.HashSet;
005import java.util.Set;
006
007import org.cpsolver.coursett.constraint.SpreadConstraint;
008import org.cpsolver.coursett.model.Lecture;
009import org.cpsolver.coursett.model.Placement;
010import org.cpsolver.ifs.assignment.Assignment;
011import org.cpsolver.ifs.util.DataProperties;
012
013
014
015/**
016 * Same subpart balancing penalty. This criterion tries to spread classes of each
017 * scheduling subpart in time. It also includes all other spread in time distribution
018 * constraints. This criterion is counted by {@link SpreadConstraint}. 
019 * <br>
020 * 
021 * @version CourseTT 1.3 (University Course Timetabling)<br>
022 *          Copyright (C) 2006 - 2014 Tomáš Müller<br>
023 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
024 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
025 * <br>
026 *          This library is free software; you can redistribute it and/or modify
027 *          it under the terms of the GNU Lesser General Public License as
028 *          published by the Free Software Foundation; either version 3 of the
029 *          License, or (at your option) any later version. <br>
030 * <br>
031 *          This library is distributed in the hope that it will be useful, but
032 *          WITHOUT ANY WARRANTY; without even the implied warranty of
033 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
034 *          Lesser General Public License for more details. <br>
035 * <br>
036 *          You should have received a copy of the GNU Lesser General Public
037 *          License along with this library; if not see
038 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
039 */
040public class SameSubpartBalancingPenalty extends TimetablingCriterion {
041    
042    public SameSubpartBalancingPenalty() {
043        setValueUpdateType(ValueUpdateType.NoUpdate);
044    }
045    
046    @Override
047    public double getWeightDefault(DataProperties config) {
048        return 12.0 * config.getPropertyDouble("Comparator.SpreadPenaltyWeight", 1.0);
049    }
050
051    @Override
052    public String getPlacementSelectionWeightName() {
053        return "Placement.SpreadPenaltyWeight";
054    }
055
056    @Override
057    public double getValue(Assignment<Lecture, Placement> assignment, Placement value, Set<Placement> conflicts) {
058        double ret = 0.0;
059        for (SpreadConstraint sc: value.variable().getSpreadConstraints())
060            ret += sc.getPenalty(assignment, value);
061        return ret / 12.0;
062    }
063    
064    @Override
065    public double getValue(Assignment<Lecture, Placement> assignment) {
066        return super.getValue(assignment) / 12.0;
067    }
068    
069    @Override
070    public double getValue(Assignment<Lecture, Placement> assignment, Collection<Lecture> variables) {
071        double ret = 0;
072        Set<SpreadConstraint> constraints = new HashSet<SpreadConstraint>();
073        for (Lecture lect: variables) {
074            for (SpreadConstraint sc: lect.getSpreadConstraints()) {
075                if (!constraints.add(sc)) continue;
076                ret += sc.getPenalty(assignment);
077            }
078        }
079        return ret / 12.0;
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}