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}