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.Constants;
007 import net.sf.cpsolver.coursett.model.Lecture;
008 import net.sf.cpsolver.coursett.model.Placement;
009 import net.sf.cpsolver.coursett.model.TimeLocation;
010 import 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 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 public 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 = preference(value);
062 if (conflicts != null)
063 for (Placement conflict: conflicts)
064 ret -= 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] += p[0];
075 bounds[1] += p[1];
076 }
077 return bounds;
078 }
079
080 }