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 * @author  Tomáš Müller
022 * @version CourseTT 1.3 (University Course Timetabling)<br>
023 *          Copyright (C) 2006 - 2014 Tomáš Müller<br>
024 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
025 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
026 * <br>
027 *          This library is free software; you can redistribute it and/or modify
028 *          it under the terms of the GNU Lesser General Public License as
029 *          published by the Free Software Foundation; either version 3 of the
030 *          License, or (at your option) any later version. <br>
031 * <br>
032 *          This library is distributed in the hope that it will be useful, but
033 *          WITHOUT ANY WARRANTY; without even the implied warranty of
034 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
035 *          Lesser General Public License for more details. <br>
036 * <br>
037 *          You should have received a copy of the GNU Lesser General Public
038 *          License along with this library; if not see
039 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
040 */
041public class SameSubpartBalancingPenalty extends TimetablingCriterion {
042    
043    public SameSubpartBalancingPenalty() {
044        setValueUpdateType(ValueUpdateType.NoUpdate);
045    }
046    
047    @Override
048    public double getWeightDefault(DataProperties config) {
049        return 12.0 * config.getPropertyDouble("Comparator.SpreadPenaltyWeight", 1.0);
050    }
051
052    @Override
053    public String getPlacementSelectionWeightName() {
054        return "Placement.SpreadPenaltyWeight";
055    }
056
057    @Override
058    public double getValue(Assignment<Lecture, Placement> assignment, Placement value, Set<Placement> conflicts) {
059        double ret = 0.0;
060        for (SpreadConstraint sc: value.variable().getSpreadConstraints())
061            ret += sc.getPenalty(assignment, value);
062        return ret / 12.0;
063    }
064    
065    @Override
066    public double getValue(Assignment<Lecture, Placement> assignment) {
067        return super.getValue(assignment) / 12.0;
068    }
069    
070    @Override
071    public double getValue(Assignment<Lecture, Placement> assignment, Collection<Lecture> variables) {
072        double ret = 0;
073        Set<SpreadConstraint> constraints = new HashSet<SpreadConstraint>();
074        for (Lecture lect: variables) {
075            for (SpreadConstraint sc: lect.getSpreadConstraints()) {
076                if (!constraints.add(sc)) continue;
077                ret += sc.getPenalty(assignment);
078            }
079        }
080        return ret / 12.0;
081    }
082    
083    @Override
084    public double[] getBounds(Assignment<Lecture, Placement> assignment) {
085        return new double[] { 0.0, 0.0 };
086    }
087    
088    @Override
089    public double[] getBounds(Assignment<Lecture, Placement> assignment, Collection<Lecture> variables) {
090        return new double[] { 0.0, 0.0 };
091    }
092}