001package org.cpsolver.instructor.criteria; 002 003import java.util.Collection; 004import java.util.Set; 005 006import org.cpsolver.ifs.assignment.Assignment; 007import org.cpsolver.ifs.util.DataProperties; 008import org.cpsolver.instructor.model.Instructor; 009import org.cpsolver.instructor.model.TeachingAssignment; 010import org.cpsolver.instructor.model.TeachingRequest; 011 012/** 013 * Same Course Preferences. This criterion counts how well are the same course preferences that are set on a {@link TeachingRequest} met 014 * (counting {@link TeachingRequest#getSameCoursePenalty(TeachingRequest)}). 015 * 016 * @version IFS 1.3 (Instructor Sectioning)<br> 017 * Copyright (C) 2016 Tomáš Müller<br> 018 * <a href="mailto:muller@unitime.org">muller@unitime.org</a><br> 019 * <a href="http://muller.unitime.org">http://muller.unitime.org</a><br> 020 * <br> 021 * This library is free software; you can redistribute it and/or modify 022 * it under the terms of the GNU Lesser General Public License as 023 * published by the Free Software Foundation; either version 3 of the 024 * License, or (at your option) any later version. <br> 025 * <br> 026 * This library is distributed in the hope that it will be useful, but 027 * WITHOUT ANY WARRANTY; without even the implied warranty of 028 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 029 * Lesser General Public License for more details. <br> 030 * <br> 031 * You should have received a copy of the GNU Lesser General Public 032 * License along with this library; if not see 033 * <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>. 034 */ 035public class SameCourse extends InstructorSchedulingCriterion { 036 037 public SameCourse() { 038 setValueUpdateType(ValueUpdateType.NoUpdate); 039 } 040 041 @Override 042 public double getWeightDefault(DataProperties config) { 043 return 1000000.0; 044 } 045 046 @Override 047 public double getValue(Assignment<TeachingRequest.Variable, TeachingAssignment> assignment, TeachingAssignment value, Set<TeachingAssignment> conflicts) { 048 Instructor.Context context = value.getInstructor().getContext(assignment); 049 double penalty = 0.0; 050 int pairs = 0; 051 for (TeachingAssignment ta : context.getAssignments()) { 052 if (ta.variable().equals(value.variable())) 053 continue; 054 penalty += value.variable().getRequest().getSameCoursePenalty(ta.variable().getRequest()); 055 pairs ++; 056 } 057 return (pairs == 0 ? 0.0 : penalty / pairs); 058 } 059 060 @Override 061 public double[] getBounds(Assignment<TeachingRequest.Variable, TeachingAssignment> assignment, Collection<TeachingRequest.Variable> variables) { 062 double[] bounds = new double[] { 0.0, 0.0 }; 063 for (TeachingRequest.Variable req: variables) { 064 if (!req.getRequest().isSameCourseProhibited() && !req.getRequest().isSameCourseRequired()) 065 if (req.getRequest().getSameCoursePreference() < 0) { 066 bounds[0] += req.getRequest().getSameCoursePreference(); 067 } else { 068 bounds[1] += req.getRequest().getSameCoursePreference(); 069 } 070 } 071 return bounds; 072 } 073 074 @Override 075 public double getValue(Assignment<TeachingRequest.Variable, TeachingAssignment> assignment, Collection<TeachingRequest.Variable> variables) { 076 return 0.5 * super.getValue(assignment, variables); 077 } 078 079 @Override 080 public String getAbbreviation() { 081 return "SameCourse"; 082 } 083}