001 package net.sf.cpsolver.coursett.criteria;
002
003 import java.util.Collection;
004 import java.util.HashSet;
005 import java.util.Set;
006
007 import net.sf.cpsolver.coursett.constraint.GroupConstraint;
008 import net.sf.cpsolver.coursett.model.Lecture;
009 import net.sf.cpsolver.coursett.model.Placement;
010 import net.sf.cpsolver.coursett.model.TimetableModel;
011 import net.sf.cpsolver.ifs.util.DataProperties;
012
013 /**
014 * Distribution preferences. This criterion counts how well the soft distribution preferences
015 * are met. This is a sum of {@link GroupConstraint#getPreference()} of all soft distribution
016 * (group) constraints.
017 * <br>
018 *
019 * @version CourseTT 1.2 (University Course Timetabling)<br>
020 * Copyright (C) 2006 - 2011 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 */
038 public class DistributionPreferences extends TimetablingCriterion {
039
040 public DistributionPreferences() {
041 iValueUpdateType = ValueUpdateType.NoUpdate;
042 }
043
044 @Override
045 public double getWeightDefault(DataProperties config) {
046 return config.getPropertyDouble("Comparator.ContrPreferenceWeight", 1.0);
047 }
048
049 @Override
050 public String getPlacementSelectionWeightName() {
051 return "Placement.ConstrPreferenceWeight";
052 }
053
054
055 @Override
056 public double getValue(Placement value, Set<Placement> conflicts) {
057 double ret = 0.0;
058 for (GroupConstraint gc : value.variable().groupConstraints())
059 ret += gc.getCurrentPreference(value);
060 return ret;
061 }
062
063 @Override
064 public double getValue(Collection<Lecture> variables) {
065 double ret = 0;
066 Set<GroupConstraint> constraints = new HashSet<GroupConstraint>();
067 for (Lecture lect: variables) {
068 for (GroupConstraint gc: lect.groupConstraints()) {
069 if (!constraints.add(gc)) continue;
070 ret += Math.min(0, gc.getCurrentPreference());
071 }
072 }
073 return ret;
074 }
075
076 @Override
077 protected double[] computeBounds() {
078 double[] bounds = new double[] { 0.0, 0.0 };
079 for (GroupConstraint gc: ((TimetableModel)getModel()).getGroupConstraints()) {
080 if (!gc.isHard())
081 bounds[0] -= Math.abs(gc.getPreference());
082 }
083 return bounds;
084 }
085
086 @Override
087 public double[] getBounds(Collection<Lecture> variables) {
088 double[] bounds = new double[] { 0.0, 0.0 };
089 Set<GroupConstraint> constraints = new HashSet<GroupConstraint>();
090 for (Lecture lect: variables) {
091 for (GroupConstraint gc: lect.groupConstraints()) {
092 if (!gc.isHard() && constraints.add(gc))
093 bounds[0] -= Math.abs(gc.getPreference());
094 }
095 }
096 return bounds;
097 }
098 }