Package com.irurueta.numerical.roots

Class FalsePositionSingleRootEstimator

java.lang.Object

com.irurueta.numerical.roots.RootEstimator

com.irurueta.numerical.roots.SingleRootEstimator

com.irurueta.numerical.roots.BracketedSingleRootEstimator

com.irurueta.numerical.roots.FalsePositionSingleRootEstimator

public class FalsePositionSingleRootEstimator
extends BracketedSingleRootEstimator

Computes a root for a single dimension function inside a given bracket of values, in other words, root will only be searched within provided minimum and maximum evaluation points. This class is based on the false position algorithm. This implementation is based on Numerical Recipes 3rd ed. Section 9.2 page 451.

Field Summary

Fields

Modifier and Type	Field	Description
static final double	DEFAULT_TOLERANCE	Constant defining default tolerance to find a root.
static final int	MAXIT	Maximum allowed number of iterations.
static final double	MIN_TOLERANCE	Minimum allowed tolerance that can be set.
private double	tolerance	Tolerance to find a root.

Fields inherited from class com.irurueta.numerical.roots.BracketedSingleRootEstimator

BRACKET_EPS, bracketAvailable, DEFAULT_MAX_EVAL_POINT, DEFAULT_MIN_EVAL_POINT, FACTOR, maxEvalPoint, minEvalPoint, NTRY

Fields inherited from class com.irurueta.numerical.roots.SingleRootEstimator

listener, root, rootAvailable

Fields inherited from class com.irurueta.numerical.roots.RootEstimator

locked

Constructor Summary

Constructors

Constructor	Description
FalsePositionSingleRootEstimator()	Empty constructor.
FalsePositionSingleRootEstimator(SingleDimensionFunctionEvaluatorListener listener, double minEvalPoint, double maxEvalPoint, double tolerance)	Constructor.

Method Summary

Modifier and Type	Method	Description
void	estimate()	Estimates a single root of the provided single dimension function contained within a given bracket of values.
double	getTolerance()	Returns tolerance to find a root.
private void	internalSetTolerance(double tolerance)	Internal method to set tolerance to find a root.
boolean	isReady()	Returns boolean indicating whether this instance is ready to compute a root.
void	setTolerance(double tolerance)	Sets tolerance to find a root.

Methods inherited from class com.irurueta.numerical.roots.BracketedSingleRootEstimator

computeBracket, computeBracket, computeBracket, getMaxEvaluationPoint, getMinEvaluationPoint, isBracketAvailable, setBracket, sign, swap

Methods inherited from class com.irurueta.numerical.roots.SingleRootEstimator

getListener, getRoot, isListenerAvailable, isRootAvailable, setListener

Methods inherited from class com.irurueta.numerical.roots.RootEstimator

isLocked

Methods inherited from class java.lang.Object

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

Field Details

MAXIT

public static final int MAXIT

Maximum allowed number of iterations.

See Also:

• Constant Field Values

DEFAULT_TOLERANCE

public static final double DEFAULT_TOLERANCE

Constant defining default tolerance to find a root.

See Also:

• Constant Field Values

MIN_TOLERANCE

public static final double MIN_TOLERANCE

Minimum allowed tolerance that can be set.

See Also:

• Constant Field Values

tolerance

private double tolerance

Tolerance to find a root. Whenever the variation of the estimated root is smaller than the provided tolerance, then the algorithm is assumed to be converged.

Constructor Details

FalsePositionSingleRootEstimator

public FalsePositionSingleRootEstimator()

Empty constructor.

FalsePositionSingleRootEstimator

public FalsePositionSingleRootEstimator(SingleDimensionFunctionEvaluatorListener listener,
 double minEvalPoint,
 double maxEvalPoint,
 double tolerance)
                                 throws InvalidBracketRangeException

Constructor.

Parameters:

listener - Listener to evaluate a single dimension function f(x) to find its roots.

minEvalPoint - Smallest value inside the bracket of values where the root will be searched.

maxEvalPoint - Largest value inside the bracket of values where the root will be searched.

tolerance - Tolerance to find a root. During the estimation of a root, if the variation of the estimated root is smaller than the provided tolerance, then the algorithm is assumed to be converged, and the root is ensured to have an accuracy that equals tolerance.

Throws:

InvalidBracketRangeException - Raised if minEvalPoint < maxEvalPoint.

IllegalArgumentException - Raised if provided tolerance is negative.

Method Details

getTolerance

public double getTolerance()

Returns tolerance to find a root. Whenever the variation of the estimated root is smaller than returned tolerance, then the algorithm is assumed to be converged, and the estimated root is ensured to have an accuracy that equals the returned tolerance.

Returns:

Tolerance to find a root.

setTolerance

public void setTolerance(double tolerance)
                  throws LockedException

Sets tolerance to find a root. Whenever the variation of the estimated root is smaller than provided tolerance, then the algorithm is assumed to be converged, and the estimated root is ensured to have an accuracy that equals provided tolerance.

Parameters:

tolerance - Tolerance to find a root.

Throws:

LockedException - Raised if this instance is locked while doing some computations.

IllegalArgumentException - Raised if provided tolerance is negative.

estimate

public void estimate()
              throws LockedException,
NotReadyException,
RootEstimationException

Estimates a single root of the provided single dimension function contained within a given bracket of values.

Overrides:

estimate in class RootEstimator

Throws:

LockedException - Exception raised if this instance is already locked.

NotReadyException - Exception raised if not enough parameters have been provided in order to start the estimation.

RootEstimationException - Raised if the root estimation failed for some other reason (usually inability to evaluate the function, numerical instability or convergence problems, or no roots are found).

isReady

public boolean isReady()

Returns boolean indicating whether this instance is ready to compute a root. This instance is ready as soon as a listener is provided and a bracket is provided or computed.

Overrides:

isReady in class SingleRootEstimator

Returns:

True if instance is ready, false otherwise

internalSetTolerance

private void internalSetTolerance(double tolerance)

Internal method to set tolerance to find a root. This method does not check whether this instance is locked. Whenever the variation of the estimated root is smaller than provided tolerance, then the algorithm is assumed to be converged, and the estimated root is ensured to have an accuracy that equals provided tolerance.

Parameters:

tolerance - Tolerance to find a root.

Throws:

IllegalArgumentException - Raised if provided tolerance is negative.