001package org.cpsolver.exam.criteria; 002 003import java.util.Collection; 004import java.util.Map; 005import java.util.Set; 006 007import org.cpsolver.exam.model.Exam; 008import org.cpsolver.exam.model.ExamModel; 009import org.cpsolver.exam.model.ExamPlacement; 010import org.cpsolver.ifs.assignment.Assignment; 011import org.cpsolver.ifs.solver.Solver; 012import org.cpsolver.ifs.util.DataProperties; 013 014 015/** 016 * Front load penalty. I.e., large exam is discouraged to be placed on or after a 017 * certain period. 018 * <br><br> 019 * <b>largeSize</b>: An exam is considered large, if its size is greater or equal to 020 * this number. Value -1 means all exams are small. It can be set by problem 021 * property Exams.LargeSize, or in the input xml file, property largeSize. 022 * <br><br> 023 * <b>largePeriod</b>: Period index (number of periods multiplied by this number) for front load 024 * criteria for large exams. Can be set by problem property 025 * Exams.LargePeriod, or in the input xml file, property largePeriod. 026 * <br><br> 027 * Weight of the front load criterion, i.e., a weight for assigning a large exam 028 * after large period can be set by problem property Exams.LargeWeight, or 029 * in the input xml file, property largeWeight. 030 * 031 * <br> 032 * 033 * @version ExamTT 1.3 (Examination Timetabling)<br> 034 * Copyright (C) 2008 - 2014 Tomas Muller<br> 035 * <a href="mailto:muller@unitime.org">muller@unitime.org</a><br> 036 * <a href="http://muller.unitime.org">http://muller.unitime.org</a><br> 037 * <br> 038 * This library is free software; you can redistribute it and/or modify 039 * it under the terms of the GNU Lesser General Public License as 040 * published by the Free Software Foundation; either version 3 of the 041 * License, or (at your option) any later version. <br> 042 * <br> 043 * This library is distributed in the hope that it will be useful, but 044 * WITHOUT ANY WARRANTY; without even the implied warranty of 045 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 046 * Lesser General Public License for more details. <br> 047 * <br> 048 * You should have received a copy of the GNU Lesser General Public 049 * License along with this library; if not see 050 * <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>. 051 */ 052public class LargeExamsPenalty extends ExamCriterion { 053 private int iLargeSize = -1; 054 private double iLargePeriod = 0.67; 055 056 @Override 057 public String getWeightName() { 058 return "Exams.LargeWeight"; 059 } 060 061 @Override 062 public String getXmlWeightName() { 063 return "largeWeight"; 064 } 065 066 @Override 067 public void getXmlParameters(Map<String, String> params) { 068 params.put(getXmlWeightName(), String.valueOf(getWeight())); 069 params.put("largeSize", String.valueOf(getLargeSize())); 070 params.put("largePeriod", String.valueOf(getLargePeriod())); 071 } 072 073 @Override 074 public void setXmlParameters(Map<String, String> params) { 075 try { 076 setWeight(Double.valueOf(params.get(getXmlWeightName()))); 077 } catch (NumberFormatException e) {} catch (NullPointerException e) {} 078 try { 079 setLargeSize(Integer.valueOf(params.get("largeSize"))); 080 } catch (NumberFormatException e) {} catch (NullPointerException e) {} 081 try { 082 setLargePeriod(Double.valueOf(params.get("largePeriod"))); 083 } catch (NumberFormatException e) {} catch (NullPointerException e) {} 084 } 085 086 @Override 087 public double getWeightDefault(DataProperties config) { 088 return 1.0; 089 } 090 091 @Override 092 public boolean init(Solver<Exam, ExamPlacement> solver) { 093 boolean ret = super.init(solver); 094 iLargeSize = solver.getProperties().getPropertyInt("Exams.LargeSize", iLargeSize); 095 iLargePeriod = solver.getProperties().getPropertyDouble("Exams.LargePeriod", iLargePeriod); 096 return ret; 097 } 098 099 /** 100 * An exam is considered large, if its size is greater or equal to this 101 * large size. Value -1 means all exams are small. Can be set by problem 102 * property Exams.LargeSize, or in the input xml file, property largeSize) 103 * @return large size 104 **/ 105 public int getLargeSize() { 106 return iLargeSize; 107 } 108 109 /** 110 * An exam is considered large, if its size is greater or equal to this 111 * large size. Value -1 means all exams are small. Can be set by problem 112 * property Exams.LargeSize, or in the input xml file, property largeSize) 113 * @param largeSize large size 114 **/ 115 public void setLargeSize(int largeSize) { 116 iLargeSize = largeSize; 117 } 118 119 /** 120 * Period index (number of periods multiplied by this number) for front load 121 * criteria for large exams. Can be set by problem property 122 * Exams.LargePeriod, or in the input xml file, property largePeriod) 123 * @return large period 124 **/ 125 public double getLargePeriod() { 126 return iLargePeriod; 127 } 128 129 /** 130 * Period index (number of periods multiplied by this number) for front load 131 * criteria for large exams. Can be set by problem property 132 * Exams.LargePeriod, or in the input xml file, property largePeriod) 133 * @param largePeriod large period 134 **/ 135 public void setLargePeriod(double largePeriod) { 136 iLargePeriod = largePeriod; 137 } 138 139 140 public int getLargePeriodIndex() { 141 return (int) Math.round(((ExamModel)getModel()).getPeriods().size() * iLargePeriod); 142 } 143 144 @Override 145 public double getValue(Assignment<Exam, ExamPlacement> assignment, ExamPlacement value, Set<ExamPlacement> conflicts) { 146 Exam exam = value.variable(); 147 if (getLargeSize() < 0 || exam.getSize() < getLargeSize()) return 0; 148 return (value.getPeriod().getIndex() < getLargePeriodIndex() ? 0 : 1); 149 } 150 151 @Override 152 public double[] getBounds(Assignment<Exam, ExamPlacement> assignment, Collection<Exam> variables) { 153 double[] bounds = new double[] { 0.0, 0.0 }; 154 for (Exam exam : variables) { 155 if (getLargeSize() >= 0 && exam.getSize() >= getLargeSize()) 156 bounds[1] += 1.0; 157 } 158 return bounds; 159 } 160 161 @Override 162 public String toString(Assignment<Exam, ExamPlacement> assignment) { 163 return (getValue(assignment) <= 0.0 ? "" : "LP:" + sDoubleFormat.format(getValue(assignment))); 164 } 165}