    001package net.sf.cpsolver.coursett.criteria;
    002
    003import java.util.Collection;
    004import java.util.Set;
    005
    006import net.sf.cpsolver.coursett.Constants;
    007import net.sf.cpsolver.coursett.model.Lecture;
    008import net.sf.cpsolver.coursett.model.Placement;
    009import net.sf.cpsolver.coursett.model.TimeLocation;
    010import net.sf.cpsolver.ifs.util.DataProperties;
    011
    012/**
    013 * Time preferences. This criterion counts how well the time preferences are met. This is
    014 * a sum of {@link TimeLocation#getNormalizedPreference()} of the assigned classes.
    015 * <br>
    016 *
    017 * @version CourseTT 1.2 (University Course Timetabling)<br>
    018 *          Copyright (C) 2006 - 2011 Tomáš Müller<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 */
    036public class TimePreferences extends TimetablingCriterion {
    037
    038    @Override
    039    public double getWeightDefault(DataProperties config) {
    040        return config.getPropertyDouble("Comparator.TimePreferenceWeight", 1.0);
    041    }
    042
    043    @Override
    044    public String getPlacementSelectionWeightName() {
    045        return "Placement.TimePreferenceWeight";
    046    }
    047
    048    private double preference(Placement value) {
    049        int pref = value.getTimeLocation().getPreference();
    050        if (pref < Constants.sPreferenceLevelRequired / 2)
    051            return value.variable().getMinMaxTimePreference()[0];
    052        else if (pref > Constants.sPreferenceLevelProhibited / 2)
    053            return value.variable().getMinMaxTimePreference()[1];
    054        else
    055            return value.getTimeLocation().getNormalizedPreference();
    056    }
    057
    058    @Override
    059    public double getValue(Placement value, Set<Placement> conflicts) {
    060        if (value.variable().isCommitted()) return 0.0;
    061        double ret = value.variable().getWeight() * preference(value);
    062        if (conflicts != null)
    063            for (Placement conflict: conflicts)
    064                ret -= conflict.variable().getWeight() * preference(conflict);
    065        return ret;
    066    }
    067
    068    @Override
    069    public double[] getBounds(Collection<Lecture> variables) {
    070        double[] bounds = new double[] { 0.0, 0.0 };
    071        for (Lecture lect: variables) {
    072            if (lect.isCommitted()) continue;
    073            double[] p = lect.getMinMaxTimePreference();
    074            bounds[0] += lect.getWeight() * p[0];
    075            bounds[1] += lect.getWeight() * p[1];
    076        }
    077        return bounds;
    078    }
    079
    080}