001package net.sf.cpsolver.coursett.criteria; 002 003import java.util.Collection; 004import java.util.HashSet; 005import java.util.Set; 006 007import net.sf.cpsolver.coursett.constraint.GroupConstraint; 008import net.sf.cpsolver.coursett.model.Lecture; 009import net.sf.cpsolver.coursett.model.Placement; 010import net.sf.cpsolver.coursett.model.TimetableModel; 011import 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 Tomáš Müller<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 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 += 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 bounds[1] += Math.abs(gc.getPreference()) * (gc.variables().size() * (gc.variables().size() - 1)) / 2; 083 } 084 } 085 return bounds; 086 } 087 088 @Override 089 public double[] getBounds(Collection<Lecture> variables) { 090 double[] bounds = new double[] { 0.0, 0.0 }; 091 Set<GroupConstraint> constraints = new HashSet<GroupConstraint>(); 092 for (Lecture lect: variables) { 093 for (GroupConstraint gc: lect.groupConstraints()) { 094 if (!gc.isHard() && constraints.add(gc)) { 095 bounds[0] -= Math.abs(gc.getPreference()); 096 bounds[1] += Math.abs(gc.getPreference()) * (gc.variables().size() * (gc.variables().size() - 1)) / 2; 097 } 098 } 099 } 100 return bounds; 101 } 102}