001    package net.sf.cpsolver.exam.criteria;
002    
003    import java.util.Collection;
004    import java.util.Set;
005    
006    import net.sf.cpsolver.exam.criteria.additional.PeriodViolation;
007    import net.sf.cpsolver.exam.model.Exam;
008    import net.sf.cpsolver.exam.model.ExamPeriodPlacement;
009    import net.sf.cpsolver.exam.model.ExamPlacement;
010    import net.sf.cpsolver.ifs.solver.Solver;
011    import net.sf.cpsolver.ifs.util.DataProperties;
012    
013    /**
014     * Cost for using a period. See {@link ExamPeriodPlacement#getPenalty()} for more details.
015     * <br><br>
016     * A weight for period penalty can be set by problem property
017     * Exams.PeriodWeight, or in the input xml file, property periodWeight.
018     * 
019     * <br>
020     * 
021     * @version ExamTT 1.2 (Examination Timetabling)<br>
022     *          Copyright (C) 2008 - 2012 Tomas Muller<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     */
040    public class PeriodPenalty extends ExamCriterion {
041        protected Integer iSoftPeriods = null;
042        
043        @Override
044        public boolean init(Solver<Exam, ExamPlacement> solver) {
045            if (super.init(solver)) {
046                iSoftPeriods = solver.getProperties().getPropertyInteger("Exam.SoftPeriods", null);
047                if (iSoftPeriods != null) {
048                    PeriodViolation pv = new PeriodViolation();
049                    getModel().addCriterion(pv);
050                    return pv.init(solver);
051                }
052            }
053            return true;
054        }
055        
056        @Override
057        public String getWeightName() {
058            return "Exams.PeriodWeight";
059        }
060        
061        @Override
062        public String getXmlWeightName() {
063            return "periodWeight";
064        }
065        
066        @Override
067        public double getWeightDefault(DataProperties config) {
068            return 1.0;
069        }
070        
071        @Override
072        public double getValue(ExamPlacement value, Set<ExamPlacement> conflicts) {
073            return (iSoftPeriods == null || (value.getPeriodPlacement().getExamPenalty() != iSoftPeriods &&  value.getPeriodPlacement().getPeriod().getPenalty() != iSoftPeriods) ? value.getPeriodPlacement().getPenalty() : 0.0);
074        }
075    
076        @Override
077        public double[] getBounds(Collection<Exam> variables) {
078            double[] bounds = new double[] { 0.0, 0.0 };
079            for (Exam exam : variables) {
080                if (!exam.getPeriodPlacements().isEmpty()) {
081                    int minPenalty = Integer.MAX_VALUE, maxPenalty = Integer.MIN_VALUE;
082                    for (ExamPeriodPlacement periodPlacement : exam.getPeriodPlacements()) {
083                        if (iSoftPeriods != null && (periodPlacement.getExamPenalty() == iSoftPeriods || periodPlacement.getPeriod().getPenalty() == iSoftPeriods)) continue;
084                        minPenalty = Math.min(minPenalty, periodPlacement.getPenalty());
085                        maxPenalty = Math.max(maxPenalty, periodPlacement.getPenalty());
086                    }
087                    bounds[0] += minPenalty;
088                    bounds[1] += maxPenalty;
089                }
090            }
091            return bounds;
092        }
093        
094        @Override
095        public String toString() {
096            return "PP:" + sDoubleFormat.format(getValue());
097        }
098    }