org.cpsolver.studentsct.extension

Class DistanceConflict

java.lang.Object

org.cpsolver.ifs.extension.Extension<V,T>

org.cpsolver.ifs.assignment.context.ExtensionWithContext<Request,Enrollment,DistanceConflict.DistanceConflictContext>

org.cpsolver.studentsct.extension.DistanceConflict

All Implemented Interfaces:

CanHoldContext, CanInheritContext<Request,Enrollment,DistanceConflict.DistanceConflictContext>, HasAssignmentContext<Request,Enrollment,DistanceConflict.DistanceConflictContext>, ModelListener<Request,Enrollment>

public class DistanceConflict
extends ExtensionWithContext<Request,Enrollment,DistanceConflict.DistanceConflictContext>
implements ModelListener<Request,Enrollment>, CanInheritContext<Request,Enrollment,DistanceConflict.DistanceConflictContext>

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. This means that the (walking) distance in minutes between the two classes are longer than the break time of the earlier class. See DistanceMetric for more details.

Version:

StudentSct 1.3 (Student Sectioning)
Copyright (C) 2007 - 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

See Also:

TimeLocation,



Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	DistanceConflict.Conflict A representation of a distance conflict
class	DistanceConflict.DistanceConflictContext

Field Summary

Fields

Modifier and Type	Field and Description
static boolean	sDebug Debug flag

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

sMaxSize

Constructor Summary

Constructors

Constructor and Description
DistanceConflict(DistanceMetric metrics, DataProperties properties) Alternative constructor (for online student sectioning)
DistanceConflict(Solver<Request,Enrollment> solver, DataProperties properties) Constructor.

Method Summary

Modifier and Type	Method and Description
void	afterAssigned(Assignment<Request,Enrollment> assignment, long iteration, Enrollment value) Called after a value is assigned to a variable.
void	afterUnassigned(Assignment<Request,Enrollment> assignment, long iteration, Enrollment value) Called after a value is unassigned from a variable.
Set<DistanceConflict.Conflict>	allConflicts(Assignment<Request,Enrollment> assignment, 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	beforeAssigned(Assignment<Request,Enrollment> assignment, long iteration, Enrollment value) Called before a value is assigned to a variable.
void	checkAllConflicts(Assignment<Request,Enrollment> assignment) Checks the counter counting all conflicts
Set<DistanceConflict.Conflict>	computeAllConflicts(Assignment<Request,Enrollment> assignment) Compute a set of all distance conflicts (DistanceConflict.Conflict objects).
Set<DistanceConflict.Conflict>	conflicts(Enrollment e1) Return a set of distance conflicts (DistanceConflict.Conflict objects) of a (course) enrollment.
Set<DistanceConflict.Conflict>	conflicts(Enrollment e1, Enrollment e2) Return a set of distance conflicts (DistanceConflict.Conflict objects) between given (course) enrollments.
int	countTotalNrConflicts(Assignment<Request,Enrollment> assignment) Compute the actual number of all distance conflicts.
DistanceConflict.DistanceConflictContext	createAssignmentContext(Assignment<Request,Enrollment> assignment) Create a new assignment context for the given assignment.
Set<DistanceConflict.Conflict>	getAllConflicts(Assignment<Request,Enrollment> assignment) Return a set of all distance conflicts (DistanceConflict.Conflict objects).
protected int	getDistanceInMinutes(Placement p1, Placement p2)
protected int	getDistanceInMinutes(RoomLocation r1, RoomLocation r2)
DistanceMetric	getDistanceMetric()
int	getTotalNrConflicts(Assignment<Request,Enrollment> assignment) Actual number of all distance conflicts
int	getTotalNrShortConflicts(Assignment<Request,Enrollment> assignment) Actual number of all distance conflicts of students that need short distances
boolean	inConflict(Student student, Section s1, Section s2) Return true if the given two sections are in distance conflict.
DistanceConflict.DistanceConflictContext	inheritAssignmentContext(Assignment<Request,Enrollment> assignment, DistanceConflict.DistanceConflictContext parentContext) Create a new assignment context for the given assignment.
int	nrConflicts(Enrollment e1) Return number of distance conflict of a (course) enrollment.
int	nrConflicts(Enrollment e1, Enrollment e2) Return number of distance conflicts that are between two enrollments.
String	toString()

Methods inherited from class org.cpsolver.ifs.assignment.context.ExtensionWithContext

getAssignmentContextReference, getContext, getContext, init, setAssignmentContextReference, unregister

Methods inherited from class org.cpsolver.ifs.extension.Extension

beforeUnassigned, constraintAdded, constraintRemoved, getModel, getProperties, getSolver, isRegistered, register, variableAdded, variableRemoved

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.cpsolver.ifs.model.ModelListener

beforeUnassigned, constraintAdded, constraintRemoved, init, variableAdded, variableRemoved

Field Detail

sDebug

public static boolean sDebug

Debug flag

Constructor Detail

DistanceConflict

public DistanceConflict(Solver<Request,Enrollment> 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

DistanceConflict

public DistanceConflict(DistanceMetric metrics,
                        DataProperties properties)

Alternative constructor (for online student sectioning)

Parameters:

metrics - distance metrics

properties - configuration

Method Detail

toString

public String toString()

Overrides:

toString in class Object

getDistanceMetric

public DistanceMetric getDistanceMetric()

getDistanceInMinutes

protected int getDistanceInMinutes(RoomLocation r1,
                                   RoomLocation r2)

getDistanceInMinutes

protected int getDistanceInMinutes(Placement p1,
                                   Placement p2)

inConflict

public boolean inConflict(Student student,
                          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:

student - a student

s1 - a section

s2 - a section

Returns:

true, if the given sections are in a distance conflict

nrConflicts

public int 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.

Parameters:

e1 - an enrollment

Returns:

number of distance conflicts

nrConflicts

public int 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.

Parameters:

e1 - an enrollment

e2 - an enrollment

Returns:

number of distance conflict between given enrollments

conflicts

public Set<DistanceConflict.Conflict> 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 Set<DistanceConflict.Conflict> 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

allConflicts

public Set<DistanceConflict.Conflict> allConflicts(Assignment<Request,Enrollment> assignment,
                                                   Enrollment enrollment)

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

Parameters:

assignment - current assignment

enrollment - given enrollment

Returns:

set of all conflicts

checkAllConflicts

public void checkAllConflicts(Assignment<Request,Enrollment> assignment)

Checks the counter counting all conflicts

Parameters:

assignment - current assignment

getTotalNrConflicts

public int getTotalNrConflicts(Assignment<Request,Enrollment> assignment)

Actual number of all distance conflicts

Parameters:

assignment - current assignment

Returns:

cached number of all distance conflicts

getTotalNrShortConflicts

public int getTotalNrShortConflicts(Assignment<Request,Enrollment> assignment)

Actual number of all distance conflicts of students that need short distances

Parameters:

assignment - current assignment

Returns:

cached number of all distance conflicts

countTotalNrConflicts

public int countTotalNrConflicts(Assignment<Request,Enrollment> assignment)

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

Parameters:

assignment - current assignment

Returns:

computed number of all distance conflicts

computeAllConflicts

public Set<DistanceConflict.Conflict> computeAllConflicts(Assignment<Request,Enrollment> assignment)

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

Parameters:

assignment - current assignment

Returns:

computed set of all distance conflicts

getAllConflicts

public Set<DistanceConflict.Conflict> getAllConflicts(Assignment<Request,Enrollment> assignment)

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

Parameters:

assignment - current assignment

Returns:

cached set of all distance conflicts

beforeAssigned

public void beforeAssigned(Assignment<Request,Enrollment> assignment,
                           long iteration,
                           Enrollment value)

Called before a value is assigned to a variable.

Specified by:

beforeAssigned in interface ModelListener<Request,Enrollment>

Overrides:

beforeAssigned in class Extension<Request,Enrollment>

Parameters:

assignment - current assignment

iteration - current iteration

value - value to be assigned

afterAssigned

public void afterAssigned(Assignment<Request,Enrollment> assignment,
                          long iteration,
                          Enrollment value)

Called after a value is assigned to a variable.

Specified by:

afterAssigned in interface ModelListener<Request,Enrollment>

Overrides:

afterAssigned in class Extension<Request,Enrollment>

Parameters:

assignment - current assignment

iteration - current iteration

value - value to be assigned

afterUnassigned

public void afterUnassigned(Assignment<Request,Enrollment> assignment,
                            long iteration,
                            Enrollment value)

Called after a value is unassigned from a variable.

Specified by:

afterUnassigned in interface ModelListener<Request,Enrollment>

Overrides:

afterUnassigned in class Extension<Request,Enrollment>

Parameters:

assignment - current assignment

iteration - current iteration

value - value to be unassigned

createAssignmentContext

public DistanceConflict.DistanceConflictContext createAssignmentContext(Assignment<Request,Enrollment> assignment)

Description copied from interface: HasAssignmentContext

Create a new assignment context for the given assignment. If there are already some variables assigned in the value, the method should make sure that the context is appropriately initialized.

Specified by:

createAssignmentContext in interface HasAssignmentContext<Request,Enrollment,DistanceConflict.DistanceConflictContext>

Parameters:

assignment - an assignment for which there needs to be an assignment context

Returns:

a new instance of the assignment context, filled according to the given assignment

inheritAssignmentContext

public DistanceConflict.DistanceConflictContext inheritAssignmentContext(Assignment<Request,Enrollment> assignment,
                                                                         DistanceConflict.DistanceConflictContext parentContext)

Description copied from interface: CanInheritContext

Create a new assignment context for the given assignment. This method can be used to clone the parent context if desired.

Specified by:

inheritAssignmentContext in interface CanInheritContext<Request,Enrollment,DistanceConflict.DistanceConflictContext>

Parameters:

assignment - an assignment for which there needs to be an assignment context

parentContext - context of the parent assignment

Returns:

a new instance of the assignment context, filled according to the given assignment