001 package net.sf.cpsolver.exam.criteria;
002
003 import java.util.Collection;
004 import java.util.Map;
005 import java.util.Set;
006
007 import net.sf.cpsolver.exam.model.Exam;
008 import net.sf.cpsolver.exam.model.ExamModel;
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 * Front load penalty. I.e., large exam is discouraged to be placed on or after a
015 * certain period.
016 * <br><br>
017 * <b>largeSize</b>: An exam is considered large, if its size is greater or equal to
018 * this number. Value -1 means all exams are small. It can be set by problem
019 * property Exams.LargeSize, or in the input xml file, property largeSize.
020 * <br><br>
021 * <b>largePeriod</b>: Period index (number of periods multiplied by this number) for front load
022 * criteria for large exams. Can be set by problem property
023 * Exams.LargePeriod, or in the input xml file, property largePeriod.
024 * <br><br>
025 * Weight of the front load criterion, i.e., a weight for assigning a large exam
026 * after large period can be set by problem property Exams.LargeWeight, or
027 * in the input xml file, property largeWeight.
028 *
029 * <br>
030 *
031 * @version ExamTT 1.2 (Examination Timetabling)<br>
032 * Copyright (C) 2008 - 2012 Tomas Muller<br>
033 * <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
034 * <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
035 * <br>
036 * This library is free software; you can redistribute it and/or modify
037 * it under the terms of the GNU Lesser General Public License as
038 * published by the Free Software Foundation; either version 3 of the
039 * License, or (at your option) any later version. <br>
040 * <br>
041 * This library is distributed in the hope that it will be useful, but
042 * WITHOUT ANY WARRANTY; without even the implied warranty of
043 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
044 * Lesser General Public License for more details. <br>
045 * <br>
046 * You should have received a copy of the GNU Lesser General Public
047 * License along with this library; if not see
048 * <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
049 */
050 public class LargeExamsPenalty extends ExamCriterion {
051 private int iLargeSize = -1;
052 private double iLargePeriod = 0.67;
053
054 @Override
055 public String getWeightName() {
056 return "Exams.LargeWeight";
057 }
058
059 @Override
060 public String getXmlWeightName() {
061 return "largeWeight";
062 }
063
064 @Override
065 public void getXmlParameters(Map<String, String> params) {
066 params.put(getXmlWeightName(), String.valueOf(getWeight()));
067 params.put("largeSize", String.valueOf(getLargeSize()));
068 params.put("largePeriod", String.valueOf(getLargePeriod()));
069 }
070
071 @Override
072 public void setXmlParameters(Map<String, String> params) {
073 try {
074 setWeight(Double.valueOf(params.get(getXmlWeightName())));
075 } catch (NumberFormatException e) {} catch (NullPointerException e) {}
076 try {
077 setLargeSize(Integer.valueOf(params.get("largeSize")));
078 } catch (NumberFormatException e) {} catch (NullPointerException e) {}
079 try {
080 setLargePeriod(Double.valueOf(params.get("largePeriod")));
081 } catch (NumberFormatException e) {} catch (NullPointerException e) {}
082 }
083
084 @Override
085 public double getWeightDefault(DataProperties config) {
086 return 1.0;
087 }
088
089 @Override
090 public boolean init(Solver<Exam, ExamPlacement> solver) {
091 boolean ret = super.init(solver);
092 iLargeSize = solver.getProperties().getPropertyInt("Exams.LargeSize", iLargeSize);
093 iLargePeriod = solver.getProperties().getPropertyDouble("Exams.LargePeriod", iLargePeriod);
094 return ret;
095 }
096
097 /**
098 * An exam is considered large, if its size is greater or equal to this
099 * large size. Value -1 means all exams are small. Can be set by problem
100 * property Exams.LargeSize, or in the input xml file, property largeSize)
101 **/
102 public int getLargeSize() {
103 return iLargeSize;
104 }
105
106 /**
107 * An exam is considered large, if its size is greater or equal to this
108 * large size. Value -1 means all exams are small. Can be set by problem
109 * property Exams.LargeSize, or in the input xml file, property largeSize)
110 **/
111 public void setLargeSize(int largeSize) {
112 iLargeSize = largeSize;
113 }
114
115 /**
116 * Period index (number of periods multiplied by this number) for front load
117 * criteria for large exams. Can be set by problem property
118 * Exams.LargePeriod, or in the input xml file, property largePeriod)
119 **/
120 public double getLargePeriod() {
121 return iLargePeriod;
122 }
123
124 /**
125 * Period index (number of periods multiplied by this number) for front load
126 * criteria for large exams. Can be set by problem property
127 * Exams.LargePeriod, or in the input xml file, property largePeriod)
128 **/
129 public void setLargePeriod(double largePeriod) {
130 iLargePeriod = largePeriod;
131 }
132
133
134 public int getLargePeriodIndex() {
135 return (int) Math.round(((ExamModel)getModel()).getPeriods().size() * iLargePeriod);
136 }
137
138 @Override
139 public double getValue(ExamPlacement value, Set<ExamPlacement> conflicts) {
140 Exam exam = value.variable();
141 if (getLargeSize() < 0 || exam.getSize() < getLargeSize()) return 0;
142 return (value.getPeriod().getIndex() < getLargePeriodIndex() ? 0 : 1);
143 }
144
145 @Override
146 public double[] getBounds(Collection<Exam> variables) {
147 double[] bounds = new double[] { 0.0, 0.0 };
148 for (Exam exam : variables) {
149 if (getLargeSize() >= 0 && exam.getSize() >= getLargeSize())
150 bounds[1] += 1.0;
151 }
152 return bounds;
153 }
154
155 @Override
156 public String toString() {
157 return (getValue() <= 0.0 ? "" : "LP:" + sDoubleFormat.format(getValue()));
158 }
159 }