org.cpsolver.coursett.criteria.additional

Class StudentMinimizeScheduleHoles

java.lang.Object

org.cpsolver.ifs.criteria.AbstractCriterion<Lecture,Placement>

org.cpsolver.coursett.criteria.TimetablingCriterion

org.cpsolver.coursett.criteria.StudentConflict

org.cpsolver.coursett.criteria.additional.StudentMinimizeScheduleHoles

All Implemented Interfaces:

CanHoldContext, HasAssignmentContext<Lecture,Placement,AbstractCriterion.ValueContext>, Criterion<Lecture,Placement>, ExtendedInfoProvider<Lecture,Placement>, InfoProvider<Lecture,Placement>, ModelListener<Lecture,Placement>

public class StudentMinimizeScheduleHoles
extends StudentConflict

Naive, yet effective approach for minimizing holes in student schedule. This criterion is based on StudentConflict and it penalizes all cases where a student has two classes taught on the same day that are not back-to-back. The penalisation is based on the time distance between the two classes, computed in hours. These penalties are weighted by Comparator.MinimizeStudentScheduleHolesWeight, which defaults to 1/20 of the Comparator.StudentConflictWeight.

Version:

CourseTT 1.3 (University Course Timetabling)
Copyright (C) 2006 - 2014 Tomáš Müller
muller@unitime.org
http://muller.unitime.org

This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with this library; if not see http://www.gnu.org/licenses/.

Author:

Tomáš Müller

Nested Class Summary

Nested classes/interfaces inherited from class org.cpsolver.ifs.criteria.AbstractCriterion

AbstractCriterion.ValueContext, AbstractCriterion.ValueUpdateType

Field Summary

Fields inherited from class org.cpsolver.coursett.criteria.StudentConflict

iIncludeConflicts

Fields inherited from class org.cpsolver.ifs.criteria.AbstractCriterion

iBest, iDebug, iWeight, sDoubleFormat, sPercentFormat

Fields inherited from interface org.cpsolver.ifs.assignment.context.CanHoldContext

sMaxSize

Constructor Summary

Constructors

Constructor and Description
StudentMinimizeScheduleHoles()

Method Summary

Modifier and Type	Method and Description
static double	btbDistance(Placement p1, Placement p2) Time distance between two placements in hours.
void	getInfo(Assignment<Lecture,Placement> assignment, Map<String,String> info) Adds some information into the table with information about the solution
void	getInfo(Assignment<Lecture,Placement> assignment, Map<String,String> info, Collection<Lecture> variables) Adds some information into the table with information about the solution, only consider variables from the given set
String	getPlacementSelectionWeightName()
double	getWeightDefault(DataProperties config) Defines default weight (when AbstractCriterion.getWeightName() parameter is not present in the criterion).
void	incJenrl(Assignment<Lecture,Placement> assignment, JenrlConstraint jenrl, double studentWeight, Double conflictPriority, Student student)
boolean	inConflict(Placement p1, Placement p2)
boolean	isApplicable(Lecture l1, Lecture l2)
protected double	jointEnrollment(JenrlConstraint jenrl)
protected double	jointEnrollment(JenrlConstraint jenrl, Placement p1, Placement p2)

Methods inherited from class org.cpsolver.coursett.criteria.StudentConflict

applicable, bestRestored, committed, configure, distance, getBounds, getBounds, getMetrics, getValue, getValue, hard, ignore, isApplicable, overlaps, slots, uncommitted, workday

Methods inherited from class org.cpsolver.coursett.criteria.TimetablingCriterion

getPlacementSelectionAdjustmentsName, getPlacementSelectionWeight, getPlacementSelectionWeightDefault

Methods inherited from class org.cpsolver.ifs.criteria.AbstractCriterion

afterAssigned, afterUnassigned, beforeAssigned, beforeUnassigned, bestSaved, clearCache, computeBounds, constraintAdded, constraintRemoved, createAssignmentContext, getAbbreviation, getAssignmentContextReference, getBest, getBounds, getBounds, getContext, getContext, getExtendedInfo, getModel, getName, getPerc, getPercentage, getPercRev, getValue, getValue, getValue, getValueUpdateType, getWeight, getWeightedBest, getWeightedValue, getWeightedValue, getWeightedValue, getWeightedValue, getWeightedValue, getWeightedValue, getWeightName, inc, inc, init, setAssignmentContextReference, setModel, setValueUpdateType, toString, variableAdded, variableRemoved

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

StudentMinimizeScheduleHoles

public StudentMinimizeScheduleHoles()

Method Detail

btbDistance

public static double btbDistance(Placement p1,
                                 Placement p2)

Time distance between two placements in hours. The classes must be on the same days and weeks, but not overlapping in time. If the two classes are taught on multiple days during the week, the distance is also multiplied by the number of shared days of week.

Parameters:

p1 - first placement

p2 - second placement

Returns:

distance between the two classes in hours

inConflict

public boolean inConflict(Placement p1,
                          Placement p2)

Overrides:

inConflict in class StudentConflict

jointEnrollment

protected double jointEnrollment(JenrlConstraint jenrl,
                                 Placement p1,
                                 Placement p2)

Overrides:

jointEnrollment in class StudentConflict

jointEnrollment

protected double jointEnrollment(JenrlConstraint jenrl)

Overrides:

jointEnrollment in class StudentConflict

isApplicable

public boolean isApplicable(Lecture l1,
                            Lecture l2)

Overrides:

isApplicable in class StudentConflict

incJenrl

public void incJenrl(Assignment<Lecture,Placement> assignment,
                     JenrlConstraint jenrl,
                     double studentWeight,
                     Double conflictPriority,
                     Student student)

Overrides:

incJenrl in class StudentConflict

getWeightDefault

public double getWeightDefault(DataProperties config)

Description copied from class: AbstractCriterion

Defines default weight (when AbstractCriterion.getWeightName() parameter is not present in the criterion).

Overrides:

getWeightDefault in class AbstractCriterion<Lecture,Placement>

Parameters:

config - solver configuration

Returns:

default criterion weight value

getPlacementSelectionWeightName

public String getPlacementSelectionWeightName()

Overrides:

getPlacementSelectionWeightName in class StudentConflict

getInfo

public void getInfo(Assignment<Lecture,Placement> assignment,
                    Map<String,String> info)

Description copied from interface: InfoProvider

Adds some information into the table with information about the solution

Specified by:

getInfo in interface InfoProvider<Lecture,Placement>

Overrides:

getInfo in class AbstractCriterion<Lecture,Placement>

Parameters:

assignment - current assignment

info - info table

getInfo

public void getInfo(Assignment<Lecture,Placement> assignment,
                    Map<String,String> info,
                    Collection<Lecture> variables)

Description copied from interface: InfoProvider

Adds some information into the table with information about the solution, only consider variables from the given set

Specified by:

getInfo in interface InfoProvider<Lecture,Placement>

Overrides:

getInfo in class AbstractCriterion<Lecture,Placement>

Parameters:

assignment - current assignment

info - info table

variables - sub-problem