001package org.cpsolver.exam.criteria; 002 003import java.util.Map; 004import java.util.Set; 005 006import org.cpsolver.exam.model.Exam; 007import org.cpsolver.exam.model.ExamPlacement; 008import org.cpsolver.ifs.assignment.Assignment; 009import org.cpsolver.ifs.solver.Solver; 010import org.cpsolver.ifs.util.DataProperties; 011 012 013/** 014 * Perturbation penalty. I.e., penalty for using a different examination period than 015 * initial. Only applicable when {@link PerturbationPenalty#isMPP()} is true (minimal 016 * perturbation problem). 017 * <br><br> 018 * A weight of perturbations (i.e., a penalty for an 019 * assignment of an exam to a place different from the initial one) can be 020 * set by problem property Exams.PerturbationWeight, or in the input xml 021 * file, property perturbationWeight). 022 * 023 * <br> 024 * 025 * @version ExamTT 1.3 (Examination Timetabling)<br> 026 * Copyright (C) 2008 - 2014 Tomas Muller<br> 027 * <a href="mailto:muller@unitime.org">muller@unitime.org</a><br> 028 * <a href="http://muller.unitime.org">http://muller.unitime.org</a><br> 029 * <br> 030 * This library is free software; you can redistribute it and/or modify 031 * it under the terms of the GNU Lesser General Public License as 032 * published by the Free Software Foundation; either version 3 of the 033 * License, or (at your option) any later version. <br> 034 * <br> 035 * This library is distributed in the hope that it will be useful, but 036 * WITHOUT ANY WARRANTY; without even the implied warranty of 037 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 038 * Lesser General Public License for more details. <br> 039 * <br> 040 * You should have received a copy of the GNU Lesser General Public 041 * License along with this library; if not see 042 * <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>. 043 */ 044public class PerturbationPenalty extends ExamCriterion { 045 private boolean iMPP = false; 046 047 @Override 048 public boolean init(Solver<Exam, ExamPlacement> solver) { 049 boolean ret = super.init(solver); 050 iMPP = solver.getProperties().getPropertyBoolean("General.MPP", iMPP); 051 return ret; 052 } 053 054 @Override 055 public String getWeightName() { 056 return "Exams.PerturbationWeight"; 057 } 058 059 @Override 060 public String getXmlWeightName() { 061 return "perturbationWeight"; 062 } 063 064 @Override 065 public double getWeightDefault(DataProperties config) { 066 return 0.01; 067 } 068 069 public boolean isMPP() { 070 return iMPP; 071 } 072 073 @Override 074 public void getXmlParameters(Map<String, String> params) { 075 params.put(getXmlWeightName(), String.valueOf(getWeight())); 076 params.put("mpp", isMPP() ? "true" : "false"); 077 } 078 079 @Override 080 public void setXmlParameters(Map<String, String> params) { 081 try { 082 setWeight(Double.valueOf(params.get(getXmlWeightName()))); 083 } catch (NumberFormatException e) {} catch (NullPointerException e) {} 084 try { 085 iMPP = "true".equals(params.get("mpp")); 086 } catch (NumberFormatException e) {} catch (NullPointerException e) {} 087 } 088 089 @Override 090 public double getValue(Assignment<Exam, ExamPlacement> assignment, ExamPlacement value, Set<ExamPlacement> conflicts) { 091 if (!isMPP()) return 0; 092 Exam exam = value.variable(); 093 ExamPlacement initial = exam.getInitialAssignment(); 094 if (initial == null) return 0; 095 return Math.abs(initial.getPeriod().getIndex() - value.getPeriod().getIndex()) * (1 + exam.getSize()); 096 } 097 098 @Override 099 public String toString(Assignment<Exam, ExamPlacement> assignment) { 100 return (isMPP() ? "IP:" + sDoubleFormat.format(getValue(assignment)) : ""); 101 } 102}