Package org.tweetyproject.math.opt.solver

Class Solver

java.lang.Object

org.tweetyproject.math.opt.solver.Solver

Direct Known Subclasses:

ApacheCommonsCMAESOptimizer, ApacheCommonsNonLinearConjugateGradientOptimizer, ApacheCommonsSimplex, BfgsSolver, CombinatoricsSolver, GlpkSolver, GradientDescent, GurobiOptimizer, HessianGradientDescent, IteratedLocalSearchOnConstrProb, LagrangeSolver, LpSolve, OctaveSqpSolver, SimpleGeneticOptimizationSolver, SimulatedAnnealingOnConstrProb, StochasticLocalSearchOnConstrProb, TabuSearchOnConstrProb

public abstract class Solver
extends Object

This abstract class models an abstract solver for constraint satisfaction or optimization problems.

Author:

Matthias Thimm

Constructor Summary

Constructors

Constructor	Description
Solver()

Method Summary

Modifier and Type	Method	Description
static Solver	getDefaultGeneralSolver()	Returns the default solver for non-linear (general) optimization problems.
static Solver	getDefaultIntegerLinearSolver()	Returns the default solver for integer linear optimization problems.
static Solver	getDefaultLinearSolver()	Returns the default solver for linear optimization problems. If a default solver for linear problems has been configured this solver is returned by this method.
static boolean	hasDefaultGeneralSolver()	Returns "true" if a default solver for general optimization problems is configured.
static boolean	hasDefaultIntegerLinearSolver()	Returns "true" if a default solver for integer linear optimization problems is configured.
static boolean	hasDefaultLinearSolver()	Returns "true" if a default solver for linear optimization problems is configured.
static boolean	isInstalled()	Checks whether the solver of this class is actually installed, i.e.
static void	setDefaultGeneralSolver(Solver solver)	Sets the default solver for non-linear (general) optimization problems.
static void	setDefaultIntegerLinearSolver(Solver solver)	Sets the default solver for integer linear optimization problems.
static void	setDefaultLinearSolver(Solver solver)	Sets the default solver for linear optimization problems.
abstract Map<Variable,Term>	solve(GeneralConstraintSatisfactionProblem problem)	Computes a solution to the given constraint satisfaction or optimization problem, i.e.

Methods inherited from class java.lang.Object

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

Constructor Details

Solver

public Solver()

Method Details

setDefaultGeneralSolver

public static void setDefaultGeneralSolver(Solver solver)

Sets the default solver for non-linear (general) optimization problems.

Parameters:

solver - some solver

setDefaultLinearSolver

public static void setDefaultLinearSolver(Solver solver)

Sets the default solver for linear optimization problems.

Parameters:

solver - some solver

setDefaultIntegerLinearSolver

public static void setDefaultIntegerLinearSolver(Solver solver)

Sets the default solver for integer linear optimization problems.

Parameters:

solver - some solver

hasDefaultGeneralSolver

public static boolean hasDefaultGeneralSolver()

Returns "true" if a default solver for general optimization problems is configured.

Returns:

"true" if a default solver for general optimization problems is configured.

hasDefaultLinearSolver

public static boolean hasDefaultLinearSolver()

Returns "true" if a default solver for linear optimization problems is configured.

Returns:

"true" if a default solver for linear optimization problems is configured.

hasDefaultIntegerLinearSolver

public static boolean hasDefaultIntegerLinearSolver()

Returns "true" if a default solver for integer linear optimization problems is configured.

Returns:

"true" if a default solver for integer linear optimization problems is configured.

getDefaultGeneralSolver

public static Solver getDefaultGeneralSolver()

Returns the default solver for non-linear (general) optimization problems. If a default solver for general problems has been configured this solver is returned by this method. If no default solver for general problems is configured, a message is printed to stderr pointing out that no default solver is configured and the application is terminated.

Returns:

the default solver for non-linear (general) optimization problems.

getDefaultIntegerLinearSolver

public static Solver getDefaultIntegerLinearSolver()

Returns the default solver for integer linear optimization problems. If a default solver for general problems has been configured this solver is returned by this method. If no default solver for general problems is configured, a message is printed to stderr pointing out that no default solver is configured and the application is terminated.

Returns:

the default solver for non-linear (general) optimization problems.

getDefaultLinearSolver

public static Solver getDefaultLinearSolver()

Returns the default solver for linear optimization problems.

If a default solver for linear problems has been configured this solver is returned by this method. If no default solver for linear problems is configured, the default solver for general optimization problems is returned. If this one is not defined as well, the ApacheCommonsSimplex solver (org.tweetyproject.math.opt.solver.ApacheCommonsSimplex) is returned (with a default setting of 50000 number of iterations that returns both positive and non-positive results) as a fallback and message is printed to stderr pointing out that no default solver is configured.

Returns:

the default solver for linear optimization problems.

solve

public abstract Map<Variable,Term> solve(GeneralConstraintSatisfactionProblem problem)
                                  throws GeneralMathException

Computes a solution to the given constraint satisfaction or optimization problem, i.e. a mapping from variables of the problem to terms.

Parameters:

problem - the actual problem

Returns:

a mapping from variables of the problem to terms.

Throws:

GeneralMathException - if something went wrong.

isInstalled

public static boolean isInstalled()
                           throws UnsupportedOperationException

Checks whether the solver of this class is actually installed, i.e. whether external binaries needed for running the solver are available and dependencies are satisfied.

Returns:

"true" if the solver of this class is installed and can therefore be instantiated and used.

Throws:

UnsupportedOperationException - if the operation is not supported