001package org.cpsolver.coursett.criteria;
002
003import java.util.Collection;
004import java.util.Set;
005
006import org.cpsolver.coursett.Constants;
007import org.cpsolver.coursett.model.Lecture;
008import org.cpsolver.coursett.model.Placement;
009import org.cpsolver.ifs.assignment.Assignment;
010import org.cpsolver.ifs.util.DataProperties;
011
012
013
014/**
015 * Room preferences. This criterion counts how well the room preferences are met. This is
016 * a sum of {@link Placement#getRoomPreference()} of the assigned classes.
017 * <br>
018 * 
019 * @version CourseTT 1.3 (University Course Timetabling)<br>
020 *          Copyright (C) 2006 - 2014 Tomas Muller<br>
021 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
022 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
023 * <br>
024 *          This library is free software; you can redistribute it and/or modify
025 *          it under the terms of the GNU Lesser General Public License as
026 *          published by the Free Software Foundation; either version 3 of the
027 *          License, or (at your option) any later version. <br>
028 * <br>
029 *          This library is distributed in the hope that it will be useful, but
030 *          WITHOUT ANY WARRANTY; without even the implied warranty of
031 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
032 *          Lesser General Public License for more details. <br>
033 * <br>
034 *          You should have received a copy of the GNU Lesser General Public
035 *          License along with this library; if not see
036 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
037 */
038public class RoomPreferences extends TimetablingCriterion {
039
040    @Override
041    public double getWeightDefault(DataProperties config) {
042        return config.getPropertyDouble("Comparator.RoomPreferenceWeight", 1.0);
043    }
044
045    @Override
046    public String getPlacementSelectionWeightName() {
047        return "Placement.RoomPreferenceWeight";
048    }
049    
050    private int preference(Placement value) {
051        int pref = value.getRoomPreference();
052        if (pref < Constants.sPreferenceLevelRequired / 2)
053            return value.variable().getMinMaxRoomPreference()[0];
054        else if (pref > Constants.sPreferenceLevelProhibited / 2)
055            return value.variable().getMinMaxRoomPreference()[1];
056        else
057            return pref;
058    }
059    
060    @Override
061    public double getValue(Assignment<Lecture, Placement> assignment, Placement value, Set<Placement> conflicts) {
062        if (value.variable().isCommitted()) return 0.0;
063        double ret = value.variable().getWeight() * preference(value);
064        if (conflicts != null)
065            for (Placement conflict: conflicts)
066                ret -= conflict.variable().getWeight() * preference(conflict);
067        return ret;
068    }
069
070    @Override
071    public double[] getBounds(Assignment<Lecture, Placement> assignment, Collection<Lecture> variables) {
072        double[] bounds = new double[] { 0.0, 0.0 };
073        for (Lecture lect: variables) {
074            if (lect.isCommitted()) continue;
075            int[] p = lect.getMinMaxRoomPreference();
076            bounds[0] += lect.getWeight() * p[0];
077            bounds[1] += lect.getWeight() * p[1];
078        }
079        return bounds;
080    }
081
082}