net.sf.tweety.math.opt.solver

Class GradientDescent

java.lang.Object

net.sf.tweety.math.opt.Solver

net.sf.tweety.math.opt.solver.GradientDescent

public class GradientDescent
extends Solver

This class implements the gradient descent method to find an optimum.

Author:

Matthias Thimm

Field Summary

Fields

Modifier and Type	Field and Description
private org.slf4j.Logger	log Logger.
private static double	MAX_STEP_LENGTH The max step length for the gradient descent.
private static double	MIN_STEP_LENGTH The min step length for the gradient descent.
double	precision The precision of the approximation.
private java.util.Map<Variable,Term>	startingPoint The starting point for the solver.

Constructor Summary

Constructors

Constructor and Description
GradientDescent(java.util.Map<Variable,Term> startingPoint) Creates a new gradient descent solver

Method Summary

Modifier and Type	Method and Description
static boolean	isInstalled()
java.util.Map<Variable,Term>	solve(ConstraintSatisfactionProblem problem) Computes a solution to the given constraint satisfaction or optimization problem, i.e.

Methods inherited from class net.sf.tweety.math.opt.Solver

getDefaultGeneralSolver, getDefaultIntegerLinearSolver, getDefaultLinearSolver, hasDefaultGeneralSolver, hasDefaultIntegerLinearSolver, hasDefaultLinearSolver, setDefaultGeneralSolver, setDefaultIntegerLinearSolver, setDefaultLinearSolver

Methods inherited from class java.lang.Object

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

Field Detail

log

private org.slf4j.Logger log

Logger.

precision

public double precision

The precision of the approximation. The actual used precision depends on the number of variables.

MAX_STEP_LENGTH

private static final double MAX_STEP_LENGTH

The max step length for the gradient descent.

See Also:

Constant Field Values

MIN_STEP_LENGTH

private static final double MIN_STEP_LENGTH

The min step length for the gradient descent.

See Also:

Constant Field Values

startingPoint

private java.util.Map<Variable,Term> startingPoint

The starting point for the solver.

Constructor Detail

GradientDescent

public GradientDescent(java.util.Map<Variable,Term> startingPoint)

Creates a new gradient descent solver

Method Detail

solve

public java.util.Map<Variable,Term> solve(ConstraintSatisfactionProblem problem)
                                   throws GeneralMathException

Description copied from class: Solver

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

Specified by:

solve in class Solver

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 java.lang.UnsupportedOperationException

Throws:

java.lang.UnsupportedOperationException