org.cpsolver.ifs.constant

Class ConstantModel<V extends Variable<V,T>,T extends Value<V,T>>

java.lang.Object

org.cpsolver.ifs.model.Model<V,T>

org.cpsolver.ifs.constant.ConstantModel<V,T>

Type Parameters:

V - Variable

T - Value

Direct Known Subclasses:

TimetableModel

public class ConstantModel<V extends Variable<V,T>,T extends Value<V,T>>
extends Model<V,T>

Extension of the model with constant variables. Such variables are excluded from the solver process, however, they can be included in constraints. Such model can allow us to build a solution on top of another solution (e.g., committed classes in the course timetabling). Constant variable has to implement interface ConstantVariable, returning ConstantVariable.isConstant() true.

Version:

IFS 1.3 (Iterative Forward Search)
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

Field Summary

Fields inherited from class org.cpsolver.ifs.model.Model

sDoubleFormat, sPercentageFormat, sTimeFormat

Constructor Summary

Constructors

Constructor and Description
ConstantModel()

Method Summary

Modifier and Type	Method and Description
void	addVariable(V variable) Adds a variable to the model
void	afterAssigned(Assignment<V,T> assignment, long iteration, T value) Called after a value is assigned to its variable.
void	afterUnassigned(Assignment<V,T> assignment, long iteration, T value) Called after a value is unassigned from its variable.
void	beforeAssigned(Assignment<V,T> assignment, long iteration, T value) Called before a value is assigned to its variable.
void	beforeUnassigned(Assignment<V,T> assignment, long iteration, T value) Called before a value is unassigned from its variable.
List<V>	constantVariables() List of constant variables
boolean	hasConstantVariables() True, if the model contains at least one constant variable.
boolean	isConstant(V variable) True, if the given variable is constant.
void	removeVariable(V variable) Removes a variable from the model

Methods inherited from class org.cpsolver.ifs.model.Model

addConstraint, addCriterion, addGlobalConstraint, addModelListener, afterAssigned, afterUnassigned, assignedVariables, assignedVariables, beforeAssigned, beforeUnassigned, bestUnassignedVariables, bestUnassignedVariables, clearAssignmentContexts, clearBest, conflictConstraints, conflictValues, conflictValues, constraints, countConstraints, countGlobalConstraints, countVariables, createAssignmentContexts, createInheritedAssignment, createReference, getBestPerturbations, getBestUnassignedVariables, getBestValue, getCriteria, getCriterion, getDefaultAssignment, getEmptyAssignment, getExtendedInfo, getExtendedInfo, getInfo, getInfo, getInfo, getInfo, getInfoProviders, getModelListeners, getPerc, getPercRev, getTotalValue, getTotalValue, getTotalValue, getTotalValue, globalConstraints, inConflict, inConflict, init, invalidateVariablesWithInitialValueCache, modelListenerOfType, nrAssignedVariables, nrAssignedVariables, nrUnassignedVariables, nrUnassignedVariables, perturbVariables, perturbVariables, perturbVariables, perturbVariables, perturbVariables, removeConstraint, removeCriterion, removeCriterion, removeGlobalConstraint, removeModelListener, removeReference, restoreBest, restoreBest, restoreBest, saveBest, saveBest, setBestValue, setDefaultAssignment, toString, toString, unassignedHardConstraints, unassignedVariables, unassignedVariables, variables, variablesWithInitialValue, weaken

Methods inherited from class java.lang.Object

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

Constructor Detail

ConstantModel

public ConstantModel()

Method Detail

constantVariables

public List<V> constantVariables()

List of constant variables

Returns:

all constants

hasConstantVariables

public boolean hasConstantVariables()

True, if the model contains at least one constant variable.

Returns:

true, if there is at least one constant in this model

isConstant

public boolean isConstant(V variable)

True, if the given variable is constant.

Parameters:

variable - given variable

Returns:

true if constant

addVariable

public void addVariable(V variable)

Adds a variable to the model

Overrides:

addVariable in class Model<V extends Variable<V,T>,T extends Value<V,T>>

Parameters:

variable - a variable

removeVariable

public void removeVariable(V variable)

Removes a variable from the model

Overrides:

removeVariable in class Model<V extends Variable<V,T>,T extends Value<V,T>>

Parameters:

variable - a variable

beforeAssigned

public void beforeAssigned(Assignment<V,T> assignment,
                           long iteration,
                           T value)

Called before a value is assigned to its variable. Constant variables are excluded from (re)assignment.

Overrides:

beforeAssigned in class Model<V extends Variable<V,T>,T extends Value<V,T>>

Parameters:

assignment - current assignment

iteration - current iteration

value - a value to be assigned

beforeUnassigned

public void beforeUnassigned(Assignment<V,T> assignment,
                             long iteration,
                             T value)

Called before a value is unassigned from its variable. Constant variables are excluded from (re)assignment.

Overrides:

beforeUnassigned in class Model<V extends Variable<V,T>,T extends Value<V,T>>

Parameters:

assignment - current assignment

iteration - current iteration

value - a value to be unassigned

afterAssigned

public void afterAssigned(Assignment<V,T> assignment,
                          long iteration,
                          T value)

Called after a value is assigned to its variable. Constant variables are excluded from (re)assignment.

Overrides:

afterAssigned in class Model<V extends Variable<V,T>,T extends Value<V,T>>

Parameters:

assignment - current assignment

iteration - current iteration

value - a value that was assigned

afterUnassigned

public void afterUnassigned(Assignment<V,T> assignment,
                            long iteration,
                            T value)

Called after a value is unassigned from its variable. Constant variables are excluded from (re)assignment.

Overrides:

afterUnassigned in class Model<V extends Variable<V,T>,T extends Value<V,T>>

Parameters:

assignment - current assignment

iteration - current iteration

value - a value that was unassigned