001package net.sf.cpsolver.exam.criteria;
002
003import java.util.Set;
004
005import net.sf.cpsolver.exam.criteria.additional.DistributionViolation;
006import net.sf.cpsolver.exam.model.Exam;
007import net.sf.cpsolver.exam.model.ExamDistributionConstraint;
008import net.sf.cpsolver.exam.model.ExamModel;
009import net.sf.cpsolver.exam.model.ExamPlacement;
010import net.sf.cpsolver.ifs.solver.Solver;
011import net.sf.cpsolver.ifs.util.DataProperties;
012
013/**
014 * Distribution penalty. I.e., sum weights of violated distribution
015 * constraints.
016 * <br><br>
017 * A weight of violated distribution soft constraints (see
018 * {@link ExamDistributionConstraint}) can be set by problem property
019 * Exams.RoomDistributionWeight, or in the input xml file, property
020 * roomDistributionWeight.
021 * 
022 * <br>
023 * 
024 * @version ExamTT 1.2 (Examination Timetabling)<br>
025 *          Copyright (C) 2008 - 2012 Tomáš Müller<br>
026 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
027 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
028 * <br>
029 *          This library is free software; you can redistribute it and/or modify
030 *          it under the terms of the GNU Lesser General Public License as
031 *          published by the Free Software Foundation; either version 3 of the
032 *          License, or (at your option) any later version. <br>
033 * <br>
034 *          This library is distributed in the hope that it will be useful, but
035 *          WITHOUT ANY WARRANTY; without even the implied warranty of
036 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
037 *          Lesser General Public License for more details. <br>
038 * <br>
039 *          You should have received a copy of the GNU Lesser General Public
040 *          License along with this library; if not see
041 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
042 */
043public class DistributionPenalty extends ExamCriterion {
044    protected Integer iSoftDistributions = null;
045    
046    public DistributionPenalty() {
047        iValueUpdateType = ValueUpdateType.NoUpdate; 
048    }
049    
050    
051    @Override
052    public boolean init(Solver<Exam, ExamPlacement> solver) {
053        if (super.init(solver)) {
054            iSoftDistributions = solver.getProperties().getPropertyInteger("Exam.SoftDistributions", null);
055            if (iSoftDistributions != null) {
056                DistributionViolation dv = new DistributionViolation();
057                getModel().addCriterion(dv);
058                return dv.init(solver);
059            }
060        }
061        return true;
062    }
063    
064    @Override
065    public String getWeightName() {
066        return "Exams.DistributionWeight";
067    }
068    
069    @Override
070    public String getXmlWeightName() {
071        return "distributionWeight";
072    }
073    
074    @Override
075    public double getWeightDefault(DataProperties config) {
076        return 1.0;
077    }
078
079    @Override
080    public double getValue(ExamPlacement value, Set<ExamPlacement> conflicts) {
081        int penalty = 0;
082        for (ExamDistributionConstraint dc : value.variable().getDistributionConstraints()) {
083            if (dc.isHard() || (iSoftDistributions != null && iSoftDistributions == dc.getWeight()))
084                continue;
085            boolean sat = dc.isSatisfied(value);
086            if (sat != dc.isSatisfied())
087                penalty += (sat ? -dc.getWeight() : dc.getWeight());
088        }
089        return penalty;
090    }
091    
092    @Override
093    public boolean isRoomCriterion() { return true; }
094    
095    /**
096     * Room related distribution penalty, i.e., sum weights of violated
097     * distribution constraints
098     */
099    @Override
100    public double getRoomValue(ExamPlacement value) {
101        int penalty = 0;
102        for (ExamDistributionConstraint dc : value.variable().getDistributionConstraints()) {
103            if (dc.isHard() || (iSoftDistributions != null && iSoftDistributions == dc.getWeight()) || !dc.isRoomRelated())
104                continue;
105            boolean sat = dc.isSatisfied(value);
106            if (sat != dc.isSatisfied())
107                penalty += (sat ? -dc.getWeight() : dc.getWeight());
108        }
109        return penalty;
110    }
111
112    
113    @Override
114    public boolean isPeriodCriterion() { return true; }
115    
116    @Override
117    public void inc(double value) {
118        if (iSoftDistributions != null && iSoftDistributions == value) {
119            getModel().getCriterion(DistributionViolation.class).inc(1.0);
120        } else if (iSoftDistributions != null && iSoftDistributions == -value) {
121            getModel().getCriterion(DistributionViolation.class).inc(-1.0);
122        } else {
123            super.inc(value);
124        }
125    }
126    
127    /**
128     * Period related distribution penalty, i.e., sum weights of violated
129     * distribution constraints
130     */
131    @Override
132    public double getPeriodValue(ExamPlacement value) {
133        int penalty = 0;
134        for (ExamDistributionConstraint dc : value.variable().getDistributionConstraints()) {
135            if (dc.isHard() || (iSoftDistributions != null && iSoftDistributions == dc.getWeight()) || !dc.isPeriodRelated())
136                continue;
137            boolean sat = dc.isSatisfied(value);
138            if (sat != dc.isSatisfied())
139                penalty += (sat ? -dc.getWeight() : dc.getWeight());
140        }
141        return penalty;
142    }
143    
144    @Override
145    protected double[] computeBounds() {
146        double[] bounds = new double[] { 0.0, 0.0 };
147        for (ExamDistributionConstraint dc : ((ExamModel)getModel()).getDistributionConstraints()) {
148            if (dc.isHard() || (iSoftDistributions != null && iSoftDistributions == dc.getWeight()))
149                continue;
150            bounds[1] += dc.getWeight();
151        }
152        return bounds;
153    }
154
155    @Override
156    public String toString() {
157        return (getValue() <= 0.0 ? "" : "DP:" + sDoubleFormat.format(getValue()));
158    }
159}