ifs.model
Class Model

java.lang.Object
  ifs.model.Model

Direct Known Subclasses:

CSPModel, JobShopModel, RPPModel, StructuredCSPModel, TimetableModel, TimetableModel

public class Model
extends Object

Generic model (definition of a problem).

It consists of variables and constraints. It has also capability of memorizing the current and the best ever found assignment.

Example usage:

MyModel model = new MyModel();
Variable a = new MyVariable("A");
model.addVariable(a);
Variable b = new MyVariable("B");
model.addVariable(b);
Variable c = new MyVariable("C");
model.addVariable(c);
Constraint constr = MyConstraint("all-different");
model.addConstraint(constr);
constr.addVariable(a);
constr.addVariable(b);
constr.addVariable(c);
solver.setInitialSolution(model);

Version:

1.0

Author:

Tomáš Müller

See Also:

Variable, Constraint, Solution, Solver

Constructor Summary

Model()
Constructor

Method Summary

void	addConstraint(Constraint constraint) Adds a constraint to the model
void	addModelListener(ModelListener listener) Adds a model listener
void	addVariable(Variable variable) Adds a variable to the model
void	afterAssigned(long iteration, Value value) Called after a value is assigned to its variable
void	afterUnassigned(long iteration, Value value) Called after a value is unassigned from its variable
Vector	assignedVariables() The list of assigned variables in the model
void	beforeAssigned(long iteration, Value value) Called before a value is assigned to its variable
void	beforeUnassigned(long iteration, Value value) Called before a value is unassigned from its variable
Vector	bestUnassignedVariables() The list of unassigned variables in the best ever found solution
Hashtable	conflictConstraints(Value value) The list of constraints which are in a conflict with the given value if it is assigned to its variable.
Set	conflictValues(Value value) Returns the set of confliction variables with this value, if it is assigned to its variable
Vector	constraints() The list of constraints in the model
int	countConstraints() The number of constraints in the model
int	countVariables() The number of variables in the model
int	getBestPerturbations() Returns the number of perturbation variables in the best ever found solution
int	getBestUnassignedVariables() Returns the number of unassigned variables in the best ever found solution
Hashtable	getInfo() Returns information about the current solution.
Vector	getModelListeners() The list of model listeners
int	getTotalValue() Value of the current solution.
boolean	init(Solver solver) Model initialization
ModelListener	modelListenerOfType(Class type) The list of model listeners that are of the given class
Vector	perturbVariables() The list of perturbation variables in the model, i.e., the variables which has an initial value but which are not assigned with this value.
void	removeConstraint(Constraint constraint) Removes a constraint from the model
void	removeModelListener(ModelListener listener) Removes a model listener
void	removeVariable(Variable variable) Removes a variable from the model
void	restoreBest() Restore the best ever found assignment into the current assignment
void	saveBest() Save the current assignment as the best ever found assignment
String	toString()
Vector	unassignedHardConstraints() The list of hard constraints which contain at least one variable that is not assigned.
Vector	unassignedVariables() The list of unassigned variables in the model
Vector	variables() The list of variables in the model
Vector	variablesWithoutInitialValue() The list of variales without initial value

Methods inherited from class java.lang.Object

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

Constructor Detail

Model

public Model()

Constructor

Method Detail

variables

public Vector variables()

The list of variables in the model

countVariables

public int countVariables()

The number of variables in the model

addVariable

public void addVariable(Variable variable)

Adds a variable to the model

removeVariable

public void removeVariable(Variable variable)

Removes a variable from the model

constraints

public Vector constraints()

The list of constraints in the model

countConstraints

public int countConstraints()

The number of constraints in the model

addConstraint

public void addConstraint(Constraint constraint)

Adds a constraint to the model

removeConstraint

public void removeConstraint(Constraint constraint)

Removes a constraint from the model

unassignedVariables

public Vector unassignedVariables()

The list of unassigned variables in the model

assignedVariables

public Vector assignedVariables()

The list of assigned variables in the model

perturbVariables

public Vector perturbVariables()

The list of perturbation variables in the model, i.e., the variables which has an initial value but which are not assigned with this value.

conflictValues

public Set conflictValues(Value value)

Returns the set of confliction variables with this value, if it is assigned to its variable

variablesWithoutInitialValue

public Vector variablesWithoutInitialValue()

The list of variales without initial value

beforeAssigned

public void beforeAssigned(long iteration,
                           Value value)

Called before a value is assigned to its variable

beforeUnassigned

public void beforeUnassigned(long iteration,
                             Value value)

Called before a value is unassigned from its variable

afterAssigned

public void afterAssigned(long iteration,
                          Value value)

Called after a value is assigned to its variable

afterUnassigned

public void afterUnassigned(long iteration,
                            Value value)

Called after a value is unassigned from its variable

toString

public String toString()

Overrides:

toString in class Object

getInfo

public Hashtable getInfo()

Returns information about the current solution. Information from all model listeners and constraints is also included.

getBestUnassignedVariables

public int getBestUnassignedVariables()

Returns the number of unassigned variables in the best ever found solution

getBestPerturbations

public int getBestPerturbations()

Returns the number of perturbation variables in the best ever found solution

saveBest

public void saveBest()

Save the current assignment as the best ever found assignment

restoreBest

public void restoreBest()

Restore the best ever found assignment into the current assignment

bestUnassignedVariables

public Vector bestUnassignedVariables()

The list of unassigned variables in the best ever found solution

getTotalValue

public int getTotalValue()

Value of the current solution. It is the sum of all assigned values, i.e., Value.toInt().

addModelListener

public void addModelListener(ModelListener listener)

Adds a model listener

removeModelListener

public void removeModelListener(ModelListener listener)

Removes a model listener

init

public boolean init(Solver solver)

Model initialization

getModelListeners

public Vector getModelListeners()

The list of model listeners

modelListenerOfType

public ModelListener modelListenerOfType(Class type)

The list of model listeners that are of the given class

conflictConstraints

public Hashtable conflictConstraints(Value value)

The list of constraints which are in a conflict with the given value if it is assigned to its variable. This means the constraints, which adds a value into the set of conflicting values in Constraint.computeConflicts(Value, Set).

unassignedHardConstraints

public Vector unassignedHardConstraints()

The list of hard constraints which contain at least one variable that is not assigned.