001    package net.sf.cpsolver.coursett.criteria;
002    
003    import java.util.Collection;
004    import java.util.Set;
005    
006    import net.sf.cpsolver.coursett.Constants;
007    import net.sf.cpsolver.coursett.model.Lecture;
008    import net.sf.cpsolver.coursett.model.Placement;
009    import net.sf.cpsolver.coursett.model.TimeLocation;
010    import 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 Tomas Muller<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     */
036    public 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 = preference(value);
062            if (conflicts != null)
063                for (Placement conflict: conflicts)
064                    ret -= 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] += p[0];
075                bounds[1] += p[1];
076            }
077            return bounds;
078        }
079    
080    }