org.sat4j.pb

Class OptToPBSATAdapter

java.lang.Object

org.sat4j.tools.SolverDecorator<IPBSolver>

org.sat4j.pb.PBSolverDecorator

org.sat4j.pb.OptToPBSATAdapter

All Implemented Interfaces:

Serializable, IPBSolver, IProblem, ISolver, RandomAccessModel

public class OptToPBSATAdapter
extends PBSolverDecorator

Utility class to use optimization solvers instead of simple SAT solvers in code meant for SAT solvers.

Author:

daniel

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
OptToPBSATAdapter(IOptimizationProblem problem)

Method Summary

Methods

Modifier and Type	Method and Description
Number	getCurrentObjectiveValue() Return the value of the objective function in the last model found.
boolean	isOptimal()
boolean	isSatisfiable() Check the satisfiability of the set of constraints contained inside the solver.
boolean	isSatisfiable(boolean global) Check the satisfiability of the set of constraints contained inside the solver.
boolean	isSatisfiable(IVecInt myAssumps) Check the satisfiability of the set of constraints contained inside the solver.
boolean	isSatisfiable(IVecInt myAssumps, boolean global) Check the satisfiability of the set of constraints contained inside the solver.
int[]	model() Provide a model (if any) for a satisfiable formula.
boolean	model(int var) Provide the truth value of a specific variable in the model.
int[]	model(PrintWriter out) Compute a minimal model according to the objective function of the IPBProblem decorated.
void	setTimeoutForFindingBetterSolution(int seconds) Allow to set a specific timeout when the solver is in optimization mode.
String	toString(String prefix) Display a textual representation of the solver configuration.

Methods inherited from class org.sat4j.pb.PBSolverDecorator

addAtLeast, addAtLeast, addAtMost, addAtMost, addExactly, addExactly, addPseudoBoolean, getObjectiveFunction, setObjectiveFunction

Methods inherited from class org.sat4j.tools.SolverDecorator

addAllClauses, addAtLeast, addAtMost, addBlockingClause, addClause, addExactly, clearDecorated, clearLearntClauses, decorated, expireTimeout, findModel, findModel, getLogPrefix, getSearchListener, getSolvingEngine, getStat, getTimeout, getTimeoutMs, isDBSimplificationAllowed, isSolverKeptHot, isVerbose, modelWithInternalVariables, nConstraints, newVar, newVar, nextFreeVarId, nVars, primeImplicant, primeImplicant, printInfos, printInfos, printStat, printStat, printStat, realNumberOfVariables, registerLiteral, removeConstr, removeSubsumedConstr, reset, setDBSimplificationAllowed, setExpectedNumberOfClauses, setKeepSolverHot, setLogPrefix, setSearchListener, setTimeout, setTimeoutMs, setTimeoutOnConflicts, setVerbose, toString, unsatExplanation

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.sat4j.specs.ISolver

addAllClauses, addAtLeast, addAtMost, addBlockingClause, addClause, addExactly, clearLearntClauses, expireTimeout, getLogPrefix, getSearchListener, getSolvingEngine, getStat, getTimeout, getTimeoutMs, isDBSimplificationAllowed, isSolverKeptHot, isVerbose, modelWithInternalVariables, newVar, nextFreeVarId, printStat, printStat, printStat, realNumberOfVariables, registerLiteral, removeConstr, removeSubsumedConstr, reset, setDBSimplificationAllowed, setExpectedNumberOfClauses, setKeepSolverHot, setLogPrefix, setSearchListener, setTimeout, setTimeoutMs, setTimeoutOnConflicts, setVerbose, unsatExplanation

Methods inherited from interface org.sat4j.specs.IProblem

findModel, findModel, nConstraints, newVar, nVars, primeImplicant, primeImplicant, printInfos, printInfos

Constructor Detail

OptToPBSATAdapter

public OptToPBSATAdapter(IOptimizationProblem problem)

Method Detail

isSatisfiable

public boolean isSatisfiable()
                      throws TimeoutException

Description copied from interface: IProblem

Check the satisfiability of the set of constraints contained inside the solver.

Specified by:

isSatisfiable in interface IProblem

Overrides:

isSatisfiable in class SolverDecorator<IPBSolver>

Returns:

true if the set of constraints is satisfiable, else false.

Throws:

TimeoutException

isSatisfiable

public boolean isSatisfiable(boolean global)
                      throws TimeoutException

Description copied from interface: IProblem

Check the satisfiability of the set of constraints contained inside the solver.

Specified by:

isSatisfiable in interface IProblem

Overrides:

isSatisfiable in class SolverDecorator<IPBSolver>

Parameters:

global - whether that call is part of a global process (i.e. optimization) or not. if (global), the timeout will not be reset between each call.

Returns:

true if the set of constraints is satisfiable, else false.

Throws:

TimeoutException

isSatisfiable

public boolean isSatisfiable(IVecInt myAssumps,
                    boolean global)
                      throws TimeoutException

Description copied from interface: IProblem

Check the satisfiability of the set of constraints contained inside the solver.

Specified by:

isSatisfiable in interface IProblem

Overrides:

isSatisfiable in class SolverDecorator<IPBSolver>

Parameters:

myAssumps - a set of literals (represented by usual non null integers in Dimacs format).

global - whether that call is part of a global process (i.e. optimization) or not. if (global), the timeout will not be reset between each call.

Returns:

true if the set of constraints is satisfiable when literals are satisfied, else false.

Throws:

TimeoutException

isSatisfiable

public boolean isSatisfiable(IVecInt myAssumps)
                      throws TimeoutException

Description copied from interface: IProblem

Check the satisfiability of the set of constraints contained inside the solver.

Specified by:

isSatisfiable in interface IProblem

Overrides:

isSatisfiable in class SolverDecorator<IPBSolver>

Parameters:

myAssumps - a set of literals (represented by usual non null integers in Dimacs format).

Returns:

true if the set of constraints is satisfiable when literals are satisfied, else false.

Throws:

TimeoutException

model

public int[] model()

Description copied from interface: IProblem

Provide a model (if any) for a satisfiable formula. That method should be called AFTER isSatisfiable() or isSatisfiable(IVecInt) if the formula is satisfiable. Else an exception UnsupportedOperationException is launched.

Specified by:

model in interface IProblem

Overrides:

model in class SolverDecorator<IPBSolver>

Returns:

a model of the formula as an array of literals to satisfy.

See Also:

IProblem.isSatisfiable(), IProblem.isSatisfiable(IVecInt)

model

public int[] model(PrintWriter out)

Compute a minimal model according to the objective function of the IPBProblem decorated.

Parameters:

out - a writer to display information in verbose mode

Since:

2.3.2

model

public boolean model(int var)

Description copied from interface: RandomAccessModel

Provide the truth value of a specific variable in the model. That method should be called AFTER isSatisfiable() if the formula is satisfiable. Else an exception UnsupportedOperationException is launched.

Specified by:

model in interface RandomAccessModel

Overrides:

model in class SolverDecorator<IPBSolver>

Parameters:

var - the variable id in Dimacs format

Returns:

the truth value of that variable in the model

See Also:

#model()

toString

public String toString(String prefix)

Description copied from interface: ISolver

Display a textual representation of the solver configuration.

Specified by:

toString in interface ISolver

Overrides:

toString in class SolverDecorator<IPBSolver>

Parameters:

prefix - the prefix to use on each line.

Returns:

a textual description of the solver internals.

isOptimal

public boolean isOptimal()

getCurrentObjectiveValue

public Number getCurrentObjectiveValue()

Return the value of the objective function in the last model found.

Returns:

Since:

2.3.2

setTimeoutForFindingBetterSolution

public void setTimeoutForFindingBetterSolution(int seconds)

Allow to set a specific timeout when the solver is in optimization mode. The solver internal timeout will be set to that value once it has found a solution. That way, the original timeout of the solver may be reduced if the solver finds quickly a solution, or increased if the solver finds regularly new solutions (thus giving more time to the solver each time).

See Also:

IOptimizationProblem.setTimeoutForFindingBetterSolution(int)