net.sf.cpsolver.studentsct.extension
Class DistanceConflict

java.lang.Object
  net.sf.cpsolver.ifs.extension.Extension
      net.sf.cpsolver.studentsct.extension.DistanceConflict

All Implemented Interfaces:

ModelListener

public class DistanceConflict
extends Extension
implements ModelListener

This extension computes student distant conflicts. Two sections that are attended by the same student are considered in a distance conflict if they are back-to-back taught in locations that are two far away. The allowed distance is provided by method getAllowedDistance(TimeLocation).

Version:

StudentSct 1.1 (Student Sectioning)
Copyright (C) 2007 Tomáš Müller
muller@unitime.org
Lazenska 391, 76314 Zlin, Czech Republic

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 2.1 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, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

See Also:

TimeLocation,



Nested Class Summary

class

DistanceConflict.Conflict A representation of a distance conflict

Field Summary

static boolean

sDebug Debug flag

Constructor Summary

DistanceConflict(Solver solver, DataProperties properties)
Constructor.

Method Summary

void	afterAssigned(long iteration, Value value) Called after a value is assigned to a variable.
void	afterUnassigned(long iteration, Value value) Called after a value is unassigned from a variable.
HashSet	allConflicts(Enrollment enrollment) The set of all conflicts (DistanceConflict.Conflict objects) of the given enrollment and other enrollments that are assignmed to the same student.
void	assigned(long iteration, Value value) Called when a value is assigned to a variable.
double	avg(double w1, double w2) Quadratic average of two weights.
void	beforeAssigned(long iteration, Value value) Called before a value is assigned to a variable.
HashSet	computeAllConflicts() Compute a set of all distance conflicts (DistanceConflict.Conflict objects).
HashSet	conflicts(Enrollment e1) Return a set of distance conflicts (DistanceConflict.Conflict objects) of a (course) enrollment.
HashSet	conflicts(Enrollment e1, Enrollment e2) Return a set of distance conflicts (DistanceConflict.Conflict objects) between given (course) enrollments.
double	countTotalNrConflicts() Compute the actual number of all distance conflicts.
double	getAllowedDistance(TimeLocation time) Allowed distance for the course that follows the given time assignment.
double	getTotalNrConflicts() Actual number of all distance conflicts
boolean	inConflict(Section s1, Section s2) Return true if the given two sections are in distance conflict.
boolean	init(Solver solver) Initialize extension
double	nrAllConflicts(Enrollment enrollment) Total sum of all conflict of the given enrollment and other enrollments that are assignmed to the same student.
double	nrConflicts(Enrollment e1) Return number of distance conflict of a (course) enrollment.
double	nrConflicts(Enrollment e1, Enrollment e2) Return number of distance conflicts that are between two enrollments.
String	toString()
void	unassigned(long iteration, Value value) Called when a value is unassigned from a variable.

Methods inherited from class net.sf.cpsolver.ifs.extension.Extension

beforeUnassigned, constraintAdded, constraintRemoved, getModel, getProperties, getSolver, isRegistered, register, unregister, useValueExtra, useVariableExtra, variableAdded, variableRemoved

Methods inherited from class java.lang.Object

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

Methods inherited from interface net.sf.cpsolver.ifs.model.ModelListener

beforeUnassigned, constraintAdded, constraintRemoved, variableAdded, variableRemoved

Field Detail

sDebug

public static boolean sDebug

Debug flag

Constructor Detail

DistanceConflict

public DistanceConflict(Solver solver,
                        DataProperties properties)

Constructor. Beside of other thigs, this constructor also uses StudentSectioningModel.setDistanceConflict(DistanceConflict) to set the this instance to the model.

Parameters:

solver - constraint solver

properties - configuration

Method Detail

init

public boolean init(Solver solver)

Initialize extension

Specified by:

init in interface ModelListener

Overrides:

init in class Extension

Parameters:

solver - IFS solver

toString

public String toString()

Overrides:

toString in class Object

inConflict

public boolean inConflict(Section s1,
                          Section s2)

Return true if the given two sections are in distance conflict. This means that the sections are back-to-back and that they are placed in locations that are two far.

Parameters:

s1 - a section

s2 - a section

Returns:

true, if the given sections are in a distance conflict

nrConflicts

public double nrConflicts(Enrollment e1)

Return number of distance conflict of a (course) enrollment. It is the number of pairs of assignments of the enrollment that are in a distance conflict, weighted by the request's weight (see Request.getWeight()).

Parameters:

e1 - an enrollment

Returns:

number of distance conflicts

nrConflicts

public double nrConflicts(Enrollment e1,
                          Enrollment e2)

Return number of distance conflicts that are between two enrollments. It is the number of pairs of assignments of these enrollments that are in a distance conflict, weighted by the average (see avg(double, double)) of the requests' weight (see Request.getWeight()).

Parameters:

e1 - an enrollment

e2 - an enrollment

Returns:

number of distance conflict between given enrollments

conflicts

public HashSet conflicts(Enrollment e1)

Return a set of distance conflicts (DistanceConflict.Conflict objects) of a (course) enrollment.

Parameters:

e1 - an enrollment

Returns:

list of distance conflicts that are between assignment of the given enrollment

conflicts

public HashSet conflicts(Enrollment e1,
                         Enrollment e2)

Return a set of distance conflicts (DistanceConflict.Conflict objects) between given (course) enrollments.

Parameters:

e1 - an enrollment

e2 - an enrollment

Returns:

list of distance conflicts that are between assignment of the given enrollments

getAllowedDistance

public double getAllowedDistance(TimeLocation time)

Allowed distance for the course that follows the given time assignment.

Parameters:

time - a time assignment of the first of two sections that are back-to-back

Returns:

the maximal allowed distance

nrAllConflicts

public double nrAllConflicts(Enrollment enrollment)

Total sum of all conflict of the given enrollment and other enrollments that are assignmed to the same student.

allConflicts

public HashSet allConflicts(Enrollment enrollment)

The set of all conflicts (DistanceConflict.Conflict objects) of the given enrollment and other enrollments that are assignmed to the same student.

assigned

public void assigned(long iteration,
                     Value value)

Called when a value is assigned to a variable. Internal number of distance conflicts is updated, see getTotalNrConflicts().

unassigned

public void unassigned(long iteration,
                       Value value)

Called when a value is unassigned from a variable. Internal number of distance conflicts is updated, see getTotalNrConflicts().

getTotalNrConflicts

public double getTotalNrConflicts()

Actual number of all distance conflicts

countTotalNrConflicts

public double countTotalNrConflicts()

Compute the actual number of all distance conflicts. Should be equal to getTotalNrConflicts().

computeAllConflicts

public HashSet computeAllConflicts()

Compute a set of all distance conflicts (DistanceConflict.Conflict objects).

avg

public double avg(double w1,
                  double w2)

Quadratic average of two weights.

beforeAssigned

public void beforeAssigned(long iteration,
                           Value value)

Called before a value is assigned to a variable.

Specified by:

beforeAssigned in interface ModelListener

Overrides:

beforeAssigned in class Extension

Parameters:

iteration - current iteration

value - value to be assigned

afterAssigned

public void afterAssigned(long iteration,
                          Value value)

Called after a value is assigned to a variable.

Specified by:

afterAssigned in interface ModelListener

Overrides:

afterAssigned in class Extension

Parameters:

iteration - current iteration

value - value to be assigned

afterUnassigned

public void afterUnassigned(long iteration,
                            Value value)

Called after a value is unassigned from a variable.

Specified by:

afterUnassigned in interface ModelListener

Overrides:

afterUnassigned in class Extension

Parameters:

iteration - current iteration

value - value to be unassigned