001package org.cpsolver.coursett.criteria; 002 003import java.util.Collection; 004import java.util.HashSet; 005import java.util.Set; 006 007import org.cpsolver.coursett.constraint.GroupConstraint; 008import org.cpsolver.coursett.model.Lecture; 009import org.cpsolver.coursett.model.Placement; 010import org.cpsolver.coursett.model.TimetableModel; 011import org.cpsolver.ifs.assignment.Assignment; 012import org.cpsolver.ifs.util.DataProperties; 013 014 015/** 016 * Distribution preferences. This criterion counts how well the soft distribution preferences 017 * are met. This is a sum of {@link GroupConstraint#getPreference()} of all soft distribution 018 * (group) constraints. 019 * <br> 020 * 021 * @version CourseTT 1.3 (University Course Timetabling)<br> 022 * Copyright (C) 2006 - 2014 Tomáš Müller<br> 023 * <a href="mailto:muller@unitime.org">muller@unitime.org</a><br> 024 * <a href="http://muller.unitime.org">http://muller.unitime.org</a><br> 025 * <br> 026 * This library is free software; you can redistribute it and/or modify 027 * it under the terms of the GNU Lesser General Public License as 028 * published by the Free Software Foundation; either version 3 of the 029 * License, or (at your option) any later version. <br> 030 * <br> 031 * This library is distributed in the hope that it will be useful, but 032 * WITHOUT ANY WARRANTY; without even the implied warranty of 033 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 034 * Lesser General Public License for more details. <br> 035 * <br> 036 * You should have received a copy of the GNU Lesser General Public 037 * License along with this library; if not see 038 * <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>. 039 */ 040public class DistributionPreferences extends TimetablingCriterion { 041 042 public DistributionPreferences() { 043 setValueUpdateType(ValueUpdateType.NoUpdate); 044 } 045 046 @Override 047 public double getWeightDefault(DataProperties config) { 048 return config.getPropertyDouble("Comparator.ContrPreferenceWeight", 1.0); 049 } 050 051 @Override 052 public String getPlacementSelectionWeightName() { 053 return "Placement.ConstrPreferenceWeight"; 054 } 055 056 057 @Override 058 public double getValue(Assignment<Lecture, Placement> assignment, Placement value, Set<Placement> conflicts) { 059 double ret = 0.0; 060 for (GroupConstraint gc : value.variable().groupConstraints()) 061 ret += gc.getCurrentPreference(assignment, value); 062 return ret; 063 } 064 065 @Override 066 public double getValue(Assignment<Lecture, Placement> assignment, Collection<Lecture> variables) { 067 double ret = 0; 068 Set<GroupConstraint> constraints = new HashSet<GroupConstraint>(); 069 for (Lecture lect: variables) { 070 for (GroupConstraint gc: lect.groupConstraints()) { 071 if (!constraints.add(gc)) continue; 072 ret += gc.getContext(assignment).getPreference(); 073 } 074 } 075 return ret; 076 } 077 078 @Override 079 protected double[] computeBounds(Assignment<Lecture, Placement> assignment) { 080 double[] bounds = new double[] { 0.0, 0.0 }; 081 for (GroupConstraint gc: ((TimetableModel)getModel()).getGroupConstraints()) { 082 if (!gc.isHard()) { 083 bounds[1] += Math.abs(gc.getPreference()) * (1 + (gc.variables().size() * (gc.variables().size() - 1)) / 2); 084 } 085 } 086 return bounds; 087 } 088 089 @Override 090 public double[] getBounds(Assignment<Lecture, Placement> assignment, Collection<Lecture> variables) { 091 double[] bounds = new double[] { 0.0, 0.0 }; 092 Set<GroupConstraint> constraints = new HashSet<GroupConstraint>(); 093 for (Lecture lect: variables) { 094 for (GroupConstraint gc: lect.groupConstraints()) { 095 if (!gc.isHard() && constraints.add(gc)) { 096 bounds[1] += Math.abs(gc.getPreference()) * (1 + (gc.variables().size() * (gc.variables().size() - 1)) / 2); 097 } 098 } 099 } 100 return bounds; 101 } 102}