001package net.sf.cpsolver.exam.criteria; 002 003import java.util.Collection; 004import java.util.Map; 005import java.util.Set; 006 007import net.sf.cpsolver.exam.model.Exam; 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 * 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 Tomáš Müller<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 */ 050public 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}