001package net.sf.cpsolver.exam.criteria; 002 003import java.util.Map; 004import java.util.Set; 005 006import net.sf.cpsolver.exam.model.Exam; 007import net.sf.cpsolver.exam.model.ExamPlacement; 008import net.sf.cpsolver.ifs.solver.Solver; 009import net.sf.cpsolver.ifs.util.DataProperties; 010 011/** 012 * Perturbation penalty. I.e., penalty for using a different examination period than 013 * initial. Only applicable when {@link PerturbationPenalty#isMPP()} is true (minimal 014 * perturbation problem). 015 * <br><br> 016 * A weight of perturbations (i.e., a penalty for an 017 * assignment of an exam to a place different from the initial one) can be 018 * set by problem property Exams.PerturbationWeight, or in the input xml 019 * file, property perturbationWeight). 020 * 021 * <br> 022 * 023 * @version ExamTT 1.2 (Examination Timetabling)<br> 024 * Copyright (C) 2008 - 2012 Tomáš Müller<br> 025 * <a href="mailto:muller@unitime.org">muller@unitime.org</a><br> 026 * <a href="http://muller.unitime.org">http://muller.unitime.org</a><br> 027 * <br> 028 * This library is free software; you can redistribute it and/or modify 029 * it under the terms of the GNU Lesser General Public License as 030 * published by the Free Software Foundation; either version 3 of the 031 * License, or (at your option) any later version. <br> 032 * <br> 033 * This library is distributed in the hope that it will be useful, but 034 * WITHOUT ANY WARRANTY; without even the implied warranty of 035 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 036 * Lesser General Public License for more details. <br> 037 * <br> 038 * You should have received a copy of the GNU Lesser General Public 039 * License along with this library; if not see 040 * <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>. 041 */ 042public class PerturbationPenalty extends ExamCriterion { 043 private boolean iMPP = false; 044 045 @Override 046 public boolean init(Solver<Exam, ExamPlacement> solver) { 047 boolean ret = super.init(solver); 048 iMPP = solver.getProperties().getPropertyBoolean("General.MPP", iMPP); 049 return ret; 050 } 051 052 @Override 053 public String getWeightName() { 054 return "Exams.PerturbationWeight"; 055 } 056 057 @Override 058 public String getXmlWeightName() { 059 return "perturbationWeight"; 060 } 061 062 @Override 063 public double getWeightDefault(DataProperties config) { 064 return 0.01; 065 } 066 067 public boolean isMPP() { 068 return iMPP; 069 } 070 071 @Override 072 public void getXmlParameters(Map<String, String> params) { 073 params.put(getXmlWeightName(), String.valueOf(getWeight())); 074 params.put("mpp", isMPP() ? "true" : "false"); 075 } 076 077 @Override 078 public void setXmlParameters(Map<String, String> params) { 079 try { 080 setWeight(Double.valueOf(params.get(getXmlWeightName()))); 081 } catch (NumberFormatException e) {} catch (NullPointerException e) {} 082 try { 083 iMPP = "true".equals(params.get("mpp")); 084 } catch (NumberFormatException e) {} catch (NullPointerException e) {} 085 } 086 087 @Override 088 public double getValue(ExamPlacement value, Set<ExamPlacement> conflicts) { 089 if (!isMPP()) return 0; 090 Exam exam = value.variable(); 091 ExamPlacement initial = exam.getInitialAssignment(); 092 if (initial == null) return 0; 093 return Math.abs(initial.getPeriod().getIndex() - value.getPeriod().getIndex()) * (1 + exam.getSize()); 094 } 095 096 @Override 097 public String toString() { 098 return (isMPP() ? "IP:" + sDoubleFormat.format(getValue()) : ""); 099 } 100}