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.DepartmentSpreadConstraint; 008import net.sf.cpsolver.coursett.model.Lecture; 009import net.sf.cpsolver.coursett.model.Placement; 010import net.sf.cpsolver.ifs.util.DataProperties; 011 012/** 013 * Department balancing penalty. This criterion tries to balance classes of each 014 * department evenly. This means that for instance each department gets a fair 015 * amount of unpopular times like early morning or late afternoon. This criterion 016 * is counted by {@link DepartmentSpreadConstraint}. 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 DepartmentBalancingPenalty extends SameSubpartBalancingPenalty { 039 040 @Override 041 public double getWeightDefault(DataProperties config) { 042 return 12.0 * config.getPropertyDouble("Comparator.DeptSpreadPenaltyWeight", 1.0); 043 } 044 045 @Override 046 public String getPlacementSelectionWeightName() { 047 return "Placement.DeptSpreadPenaltyWeight"; 048 } 049 050 @Override 051 public double getValue(Placement value, Set<Placement> conflicts) { 052 return (value.variable().getDeptSpreadConstraint() == null ? 0.0 : value.variable().getDeptSpreadConstraint().getPenalty(value)) / 12.0; 053 } 054 055 @Override 056 public double getValue(Collection<Lecture> variables) { 057 double ret = 0; 058 Set<DepartmentSpreadConstraint> constraints = new HashSet<DepartmentSpreadConstraint>(); 059 for (Lecture lect: variables) 060 if (lect.getDeptSpreadConstraint() != null && constraints.add(lect.getDeptSpreadConstraint())) 061 ret += lect.getDeptSpreadConstraint().getPenalty(); 062 return ret / 12.0; 063 } 064}