001package org.cpsolver.coursett.heuristics;
002
003import org.cpsolver.coursett.model.Lecture;
004import org.cpsolver.coursett.model.Placement;
005import org.cpsolver.ifs.criteria.Criterion;
006import org.cpsolver.ifs.model.Model;
007import org.cpsolver.ifs.solution.GeneralSolutionComparator;
008import org.cpsolver.ifs.solution.Solution;
009import org.cpsolver.ifs.util.DataProperties;
010
011/**
012 * Timetable (solution) comparator. <br>
013 * <br>
014 * The quality of a solution is expressed as a weighted sum combining soft time
015 * and classroom preferences, satisfied soft group constrains and the total
016 * number of student conflicts. This allows us to express the importance of
017 * different types of soft constraints. <br>
018 * <br>
019 * The solution comparator prefers a more complete solution (with a smaller
020 * number of unassigned variables) and a solution with a smaller number of
021 * perturbations among solutions with the same number of unassigned variables.
022 * If both solutions have the same number of unassigned variables and
023 * perturbations, the solution of better quality is selected. <br>
024 * <br>
025 * Parameters:
026 * <table border='1' summary='Related Solver Parameters'>
027 * <tr>
028 * <th>Parameter</th>
029 * <th>Type</th>
030 * <th>Comment</th>
031 * </tr>
032 * <tr>
033 * <td>Comparator.HardStudentConflictWeight</td>
034 * <td>{@link Double}</td>
035 * <td>Weight of hard student conflict (conflict between single-section classes)
036 * </td>
037 * </tr>
038 * <tr>
039 * <td>Comparator.StudentConflictWeight</td>
040 * <td>{@link Double}</td>
041 * <td>Weight of student conflict</td>
042 * </tr>
043 * <tr>
044 * <td>Comparator.TimePreferenceWeight</td>
045 * <td>{@link Double}</td>
046 * <td>Time preferences weight</td>
047 * </tr>
048 * <tr>
049 * <td>Comparator.ContrPreferenceWeight</td>
050 * <td>{@link Double}</td>
051 * <td>Group constraint preferences weight</td>
052 * </tr>
053 * <tr>
054 * <td>Comparator.RoomPreferenceWeight</td>
055 * <td>{@link Double}</td>
056 * <td>Room preferences weight</td>
057 * </tr>
058 * <tr>
059 * <td>Comparator.UselessSlotWeight</td>
060 * <td>{@link Double}</td>
061 * <td>Useless slots weight</td>
062 * </tr>
063 * <tr>
064 * <td>Comparator.TooBigRoomWeight</td>
065 * <td>{@link Double}</td>
066 * <td>Too big room weight</td>
067 * </tr>
068 * <tr>
069 * <td>Comparator.DistanceInstructorPreferenceWeight</td>
070 * <td>{@link Double}</td>
071 * <td>Distance (of the rooms of the back-to-back classes) based instructor
072 * preferences weight</td>
073 * </tr>
074 * <tr>
075 * <td>Comparator.PerturbationPenaltyWeight</td>
076 * <td>{@link Double}</td>
077 * <td>Perturbation penalty (see {@link UniversalPerturbationsCounter})</td>
078 * </tr>
079 * <tr>
080 * <td>Comparator.DeptSpreadPenaltyWeight</td>
081 * <td>{@link Double}</td>
082 * <td>Department balancing penalty (see
083 * {@link org.cpsolver.coursett.constraint.DepartmentSpreadConstraint})</td>
084 * </tr>
085 * </table>
086 * 
087 * 
088 * @version CourseTT 1.3 (University Course Timetabling)<br>
089 *          Copyright (C) 2006 - 2014 Tomáš Müller<br>
090 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
091 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
092 * <br>
093 *          This library is free software; you can redistribute it and/or modify
094 *          it under the terms of the GNU Lesser General Public License as
095 *          published by the Free Software Foundation; either version 3 of the
096 *          License, or (at your option) any later version. <br>
097 * <br>
098 *          This library is distributed in the hope that it will be useful, but
099 *          WITHOUT ANY WARRANTY; without even the implied warranty of
100 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
101 *          Lesser General Public License for more details. <br>
102 * <br>
103 *          You should have received a copy of the GNU Lesser General Public
104 *          License along with this library; if not see
105 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
106 */
107@Deprecated
108public class TimetableComparator extends GeneralSolutionComparator<Lecture, Placement> {
109
110    public TimetableComparator(DataProperties properties) {
111        super(properties);
112    }
113    
114    /** 
115     * Use {@link Model#getTotalValue()} instead.
116     * @param currentSolution current solution
117     * @return current value
118     */
119    @Deprecated
120    public double currentValue(Solution<Lecture, Placement> currentSolution) {
121        double ret = 0.0;
122        for (Criterion<Lecture, Placement> criterion: currentSolution.getModel().getCriteria())
123            ret += criterion.getWeightedValue();
124        return ret;
125    }
126    
127    /** 
128     * Use {@link Solution#getBestValue()} instead.
129     * @param currentSolution current solution
130     * @return best value
131     */
132    @Deprecated
133    public double getBest(Solution<Lecture, Placement> currentSolution) {
134        double ret = 0.0;
135        for (Criterion<Lecture, Placement> criterion: currentSolution.getModel().getCriteria())
136            ret += criterion.getWeightedBest();
137        return ret;
138    }
139}