org.apache.commons.math3.analysis.solvers

Class BaseAbstractUnivariateSolver<FUNC extends UnivariateFunction>

java.lang.Object

org.apache.commons.math3.analysis.solvers.BaseAbstractUnivariateSolver<FUNC>

Type Parameters:

FUNC - Type of function to solve.

All Implemented Interfaces:

BaseUnivariateSolver<FUNC>

Direct Known Subclasses:

AbstractDifferentiableUnivariateSolver, AbstractPolynomialSolver, AbstractUnivariateDifferentiableSolver, AbstractUnivariateSolver

public abstract class BaseAbstractUnivariateSolver<FUNC extends UnivariateFunction>
extends Object
implements BaseUnivariateSolver<FUNC>

Provide a default implementation for several functions useful to generic solvers. The default values for relative and function tolerances are 1e-14 and 1e-15, respectively. It is however highly recommended to not rely on the default, but rather carefully consider values that match user's expectations, as well as the specifics of each implementation.

Since:

2.0

Method Summary

Modifier and Type	Method and Description
double	getAbsoluteAccuracy() Get the absolute accuracy of the solver.
int	getEvaluations() Get the number of evaluations of the objective function.
double	getFunctionValueAccuracy() Get the function value accuracy of the solver.
double	getMax()
int	getMaxEvaluations() Get the maximum number of function evaluations.
double	getMin()
double	getRelativeAccuracy() Get the relative accuracy of the solver.
double	getStartValue()
double	solve(int maxEval, FUNC f, double startValue) Solve for a zero in the vicinity of startValue.
double	solve(int maxEval, FUNC f, double min, double max) Solve for a zero root in the given interval.
double	solve(int maxEval, FUNC f, double min, double max, double startValue) Solve for a zero in the given interval, start at startValue.

Methods inherited from class java.lang.Object

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

Method Detail

getMaxEvaluations

public int getMaxEvaluations()

Get the maximum number of function evaluations.

Specified by:

getMaxEvaluations in interface BaseUnivariateSolver<FUNC extends UnivariateFunction>

Returns:

the maximum number of function evaluations.

getEvaluations

public int getEvaluations()

Get the number of evaluations of the objective function. The number of evaluations corresponds to the last call to the optimize method. It is 0 if the method has not been called yet.

Specified by:

getEvaluations in interface BaseUnivariateSolver<FUNC extends UnivariateFunction>

Returns:

the number of evaluations of the objective function.

getMin

public double getMin()

Returns:

the lower end of the search interval.

getMax

public double getMax()

Returns:

the higher end of the search interval.

getStartValue

public double getStartValue()

Returns:

the initial guess.

getAbsoluteAccuracy

public double getAbsoluteAccuracy()

Get the absolute accuracy of the solver. Solutions returned by the solver should be accurate to this tolerance, i.e., if ε is the absolute accuracy of the solver and v is a value returned by one of the solve methods, then a root of the function should exist somewhere in the interval (v - ε, v + ε).

Specified by:

getAbsoluteAccuracy in interface BaseUnivariateSolver<FUNC extends UnivariateFunction>

Returns:

the absolute accuracy.

getRelativeAccuracy

public double getRelativeAccuracy()

Get the relative accuracy of the solver. The contract for relative accuracy is the same as BaseUnivariateSolver.getAbsoluteAccuracy(), but using relative, rather than absolute error. If ρ is the relative accuracy configured for a solver and v is a value returned, then a root of the function should exist somewhere in the interval (v - ρ v, v + ρ v).

Specified by:

getRelativeAccuracy in interface BaseUnivariateSolver<FUNC extends UnivariateFunction>

Returns:

the relative accuracy.

getFunctionValueAccuracy

public double getFunctionValueAccuracy()

Get the function value accuracy of the solver. If v is a value returned by the solver for a function f, then by contract, |f(v)| should be less than or equal to the function value accuracy configured for the solver.

Specified by:

getFunctionValueAccuracy in interface BaseUnivariateSolver<FUNC extends UnivariateFunction>

Returns:

the function value accuracy.

solve

public double solve(int maxEval,
                    FUNC f,
                    double min,
                    double max,
                    double startValue)
             throws TooManyEvaluationsException,
                    NoBracketingException

Solve for a zero in the given interval, start at startValue. A solver may require that the interval brackets a single zero root. Solvers that do require bracketing should be able to handle the case where one of the endpoints is itself a root.

Specified by:

solve in interface BaseUnivariateSolver<FUNC extends UnivariateFunction>

Parameters:

maxEval - Maximum number of evaluations.

f - Function to solve.

min - Lower bound for the interval.

max - Upper bound for the interval.

startValue - Start value to use.

Returns:

a value where the function is zero.

Throws:

TooManyEvaluationsException - if the allowed number of evaluations is exceeded.

NoBracketingException

solve

public double solve(int maxEval,
                    FUNC f,
                    double min,
                    double max)

Solve for a zero root in the given interval. A solver may require that the interval brackets a single zero root. Solvers that do require bracketing should be able to handle the case where one of the endpoints is itself a root.

Specified by:

solve in interface BaseUnivariateSolver<FUNC extends UnivariateFunction>

Parameters:

maxEval - Maximum number of evaluations.

f - Function to solve.

min - Lower bound for the interval.

max - Upper bound for the interval.

Returns:

a value where the function is zero.

solve

public double solve(int maxEval,
                    FUNC f,
                    double startValue)
             throws TooManyEvaluationsException,
                    NoBracketingException

Solve for a zero in the vicinity of startValue.

Specified by:

solve in interface BaseUnivariateSolver<FUNC extends UnivariateFunction>

Parameters:

maxEval - Maximum number of evaluations.

f - Function to solve.

startValue - Start value to use.

Returns:

a value where the function is zero.

Throws:

TooManyEvaluationsException - if the allowed number of evaluations is exceeded.

NoBracketingException