org.jacop.constraints

Class Sum

java.lang.Object

org.jacop.constraints.DecomposedConstraint

org.jacop.constraints.Constraint

org.jacop.constraints.Sum

public class Sum
extends Constraint

Sum constraint implements the summation over several Variable's . It provides the sum from all Variable's on the list.

Version:

4.2

Author:

Radoslaw Szymanek and Krzysztof Kuchcinski

Field Summary

Fields

Modifier and Type	Field and Description
IntVar[]	list It specifies the variables to be summed.
IntVar	sum It specifies variable sum to store the overall sum of the variables being summed up.
static String[]	xmlAttributes It specifies the arguments required to be saved by an XML format as well as the constructor being called to recreate an object from an XML format.

Fields inherited from class org.jacop.constraints.Constraint

atomicExecution, consistencyPruningEvents, earlyTerminationOK, id, increaseWeight, numberArgs, numberId, trace

Fields inherited from class org.jacop.constraints.DecomposedConstraint

queueIndex

Constructor Summary

Constructors

Constructor and Description
Sum(ArrayList<? extends IntVar> list, IntVar sum) It creates a sum constraints which sums all variables and makes it equal to variable sum.
Sum(IntVar[] list, IntVar sum) It constructs sum constraint which sums all variables and makes it equal to variable sum.

Method Summary

Modifier and Type	Method and Description
ArrayList<Var>	arguments() It returns the variables in a scope of the constraint.
void	consistency(Store store) It is a (most probably incomplete) consistency function which removes the values from variables domains.
int	getConsistencyPruningEvent(Var var) It retrieves the pruning event which causes reevaluation of the constraint.
Constraint	getGuideConstraint() It specifies a constraint which if imposed by search will enhance propagation of this constraint.
int	getGuideValue() This function provides a value which if assigned to a variable returned by getGuideVariable() will enhance propagation of this constraint.
Var	getGuideVariable() This function provides a variable which assigned a value returned by will enhance propagation of this constraint.
void	impose(Store store) It imposes the constraint in a given store.
void	increaseWeight() It increases the weight of the variables in the constraint scope.
void	removeConstraint() It removes the constraint by removing this constraint from all variables.
boolean	satisfied() It checks if the constraint is satisfied.
void	supplyGuideFeedback(boolean feedback) This function allows to provide a guide feedback.
String	toString() It produces a string representation of a constraint state.

Methods inherited from class org.jacop.constraints.Constraint

cleanAfterFailure, decompose, id, impose, imposeDecomposition, numberArgs, queueVariable, removeLevel, removeLevelLate, requiresMonotonicity, setConsistencyPruningEvent

Methods inherited from class org.jacop.constraints.DecomposedConstraint

auxiliaryVariables, derivative, imposeDecomposition

Methods inherited from class java.lang.Object

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

Field Detail

list

public IntVar[] list

It specifies the variables to be summed.

sum

public IntVar sum

It specifies variable sum to store the overall sum of the variables being summed up.

xmlAttributes

public static String[] xmlAttributes

It specifies the arguments required to be saved by an XML format as well as the constructor being called to recreate an object from an XML format.

Constructor Detail

Sum

public Sum(IntVar[] list,
           IntVar sum)

It constructs sum constraint which sums all variables and makes it equal to variable sum.

Parameters:

list -

sum -

Sum

public Sum(ArrayList<? extends IntVar> list,
           IntVar sum)

It creates a sum constraints which sums all variables and makes it equal to variable sum.

Parameters:

list - variables being summed up.

sum - the sum variable.

Method Detail

arguments

public ArrayList<Var> arguments()

Description copied from class: Constraint

It returns the variables in a scope of the constraint.

Specified by:

arguments in class Constraint

Returns:

variables in a scope of the constraint.

consistency

public void consistency(Store store)

Description copied from class: Constraint

It is a (most probably incomplete) consistency function which removes the values from variables domains. Only values which do not have any support in a solution space are removed.

Specified by:

consistency in class Constraint

Parameters:

store - constraint store within which the constraint consistency is being checked.

getConsistencyPruningEvent

public int getConsistencyPruningEvent(Var var)

Description copied from class: Constraint

It retrieves the pruning event which causes reevaluation of the constraint.

Specified by:

getConsistencyPruningEvent in class Constraint

Parameters:

var - variable for which pruning event is retrieved

Returns:

it returns the int code of the pruning event (GROUND, BOUND, ANY, NONE)

impose

public void impose(Store store)

Description copied from class: Constraint

It imposes the constraint in a given store.

Specified by:

impose in class Constraint

Parameters:

store - the constraint store to which the constraint is imposed to.

removeConstraint

public void removeConstraint()

Description copied from class: Constraint

It removes the constraint by removing this constraint from all variables.

Specified by:

removeConstraint in class Constraint

satisfied

public boolean satisfied()

Description copied from class: Constraint

It checks if the constraint is satisfied. If this function is incorrectly implemented a constraint may not be satisfied in a solution.

Specified by:

satisfied in class Constraint

Returns:

true if the constraint is for certain satisfied, false otherwise.

toString

public String toString()

Description copied from class: Constraint

It produces a string representation of a constraint state.

Specified by:

toString in class Constraint

getGuideConstraint

public Constraint getGuideConstraint()

Description copied from class: Constraint

It specifies a constraint which if imposed by search will enhance propagation of this constraint.

Overrides:

getGuideConstraint in class Constraint

Returns:

Constraint enhancing propagation of this constraint.

getGuideValue

public int getGuideValue()

Description copied from class: Constraint

This function provides a value which if assigned to a variable returned by getGuideVariable() will enhance propagation of this constraint.

Overrides:

getGuideValue in class Constraint

Returns:

Value which is a base of enhancing constraint.

getGuideVariable

public Var getGuideVariable()

Description copied from class: Constraint

This function provides a variable which assigned a value returned by will enhance propagation of this constraint.

Overrides:

getGuideVariable in class Constraint

Returns:

Variable which is a base of enhancing constraint.

supplyGuideFeedback

public void supplyGuideFeedback(boolean feedback)

Description copied from class: Constraint

This function allows to provide a guide feedback. If constraint does not propose sufficiently good enhancing constraints it will be informed so it has a chance to reexamine its efforts.

Overrides:

supplyGuideFeedback in class Constraint

Parameters:

feedback - true if the guide was useful, false otherwise.

increaseWeight

public void increaseWeight()

Description copied from class: Constraint

It increases the weight of the variables in the constraint scope.

Specified by:

increaseWeight in class Constraint