org.cpsolver.coursett.model

Class OnFlySectioning

java.lang.Object

org.cpsolver.coursett.model.OnFlySectioning

All Implemented Interfaces:

ModelListener<Lecture,Placement>

public class OnFlySectioning
extends Object
implements ModelListener<Lecture,Placement>

On fly student sectioning.

In this mode, students are resectioned after each iteration, but only between classes that are affected by the iteration. This slows down the solver, but it can dramatically improve results in the case when there is more stress put on student conflicts (e.g., Woebegon College example).

Parameters:

Related Solver Parameters

Parameter	Type	Comment
OnFlySectioning.Enabled	Boolean	Enable on fly sectioning (if enabled, students will be resectioned after each iteration)
OnFlySectioning.Recursive	Boolean	Recursively resection lectures affected by a student swap
OnFlySectioning.ConfigAsWell	Boolean	Resection students between configurations as well

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

Constructor Summary

Constructors

Constructor and Description
OnFlySectioning(TimetableModel model) Constructor

Method Summary

Modifier and Type	Method and Description
void	afterAssigned(Assignment<Lecture,Placement> assignment, long iteration, Placement value) FinalSectioning.resection(Assignment, Lecture, boolean, boolean) is called when given iteration number is greater than zero.
void	afterUnassigned(Assignment<Lecture,Placement> assignment, long iteration, Placement value) Called after a value is unassigned from its variable ( Value.variable()).
void	beforeAssigned(Assignment<Lecture,Placement> assignment, long iteration, Placement value) Called before a value is assigned to its variable ( Value.variable()).
void	beforeUnassigned(Assignment<Lecture,Placement> assignment, long iteration, Placement value) Called before a value is unassigned from its variable ( Value.variable()).
void	constraintAdded(Constraint<Lecture,Placement> constraint) Constraint is added to the model
void	constraintRemoved(Constraint<Lecture,Placement> constraint) Constraint is removed from the model
boolean	init(Solver<Lecture,Placement> solver) Initialization
void	variableAdded(Lecture variable) Variable is added to the model
void	variableRemoved(Lecture variable) Variable is removed from the model

Methods inherited from class java.lang.Object

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

Constructor Detail

OnFlySectioning

public OnFlySectioning(TimetableModel model)

Constructor

Parameters:

model - timetabling model

Method Detail

variableAdded

public void variableAdded(Lecture variable)

Description copied from interface: ModelListener

Variable is added to the model

Specified by:

variableAdded in interface ModelListener<Lecture,Placement>

Parameters:

variable - added variable

variableRemoved

public void variableRemoved(Lecture variable)

Description copied from interface: ModelListener

Variable is removed from the model

Specified by:

variableRemoved in interface ModelListener<Lecture,Placement>

Parameters:

variable - removed variable

constraintAdded

public void constraintAdded(Constraint<Lecture,Placement> constraint)

Description copied from interface: ModelListener

Constraint is added to the model

Specified by:

constraintAdded in interface ModelListener<Lecture,Placement>

Parameters:

constraint - added constraint

constraintRemoved

public void constraintRemoved(Constraint<Lecture,Placement> constraint)

Description copied from interface: ModelListener

Constraint is removed from the model

Specified by:

constraintRemoved in interface ModelListener<Lecture,Placement>

Parameters:

constraint - removed constraint

beforeAssigned

public void beforeAssigned(Assignment<Lecture,Placement> assignment,
                           long iteration,
                           Placement value)

Description copied from interface: ModelListener

Called before a value is assigned to its variable ( Value.variable()).

Specified by:

beforeAssigned in interface ModelListener<Lecture,Placement>

Parameters:

assignment - current assignment

iteration - current iteration

value - value to be assigned

beforeUnassigned

public void beforeUnassigned(Assignment<Lecture,Placement> assignment,
                             long iteration,
                             Placement value)

Description copied from interface: ModelListener

Called before a value is unassigned from its variable ( Value.variable()).

Specified by:

beforeUnassigned in interface ModelListener<Lecture,Placement>

Parameters:

assignment - current assignment

iteration - current iteration

value - value to be unassigned

afterAssigned

public void afterAssigned(Assignment<Lecture,Placement> assignment,
                          long iteration,
                          Placement value)

FinalSectioning.resection(Assignment, Lecture, boolean, boolean) is called when given iteration number is greater than zero.

Specified by:

afterAssigned in interface ModelListener<Lecture,Placement>

Parameters:

assignment - current assignment

iteration - current iteration

value - value to be assigned

afterUnassigned

public void afterUnassigned(Assignment<Lecture,Placement> assignment,
                            long iteration,
                            Placement value)

Description copied from interface: ModelListener

Called after a value is unassigned from its variable ( Value.variable()).

Specified by:

afterUnassigned in interface ModelListener<Lecture,Placement>

Parameters:

assignment - current assignment

iteration - current iteration

value - value to be unassigned

init

public boolean init(Solver<Lecture,Placement> solver)

Initialization

Specified by:

init in interface ModelListener<Lecture,Placement>

Parameters:

solver - IFS solver

Returns:

true if successfully initialized