org.josef.science.math

Class RegulaFalsi

java.lang.Object

org.josef.science.math.AbstractRootFinder

org.josef.science.math.RegulaFalsi

All Implemented Interfaces:

RootFinderStrategy

@Status(stage=PRODUCTION,
        unitTests=ABSENT)
 @Review(by="Kees Schotanus",
        at="2009-09-28")
 @ThreadSafety(level=IMMUTABLE)
public final class RegulaFalsi
extends AbstractRootFinder
implements RootFinderStrategy

Finds the roots of a function within a defined interval, using the Regula Falsi (False Position) method.
To find the root of a function f , f should at least be continuous.
More information on this topic can be found in the WikiPedia by clicking here.

Version:

1.0 $Revision: 6298 $

Author:

Kees Schotanus

Field Summary

Fields

Modifier and Type	Field and Description
static int	MAX_ITERATIONS Maximum number of iterations to perform before bailing out.

Constructor Summary

Constructors

Constructor and Description
RegulaFalsi(double accuracy) Creates this RegulaFalsi root finder using the supplied accuracy.
RegulaFalsi(int iterations) Creates this RegulaFalsi root finder using the supplied number of iterations.

Method Summary

Modifier and Type	Method and Description
double	findRoot(SingleParameterFunction function, double left, double right) Finds a root of the supplied function within the supplied interval [left, right] using the Regula Falsi method.

Methods inherited from class org.josef.science.math.AbstractRootFinder

getAccuracy, getInterval, getIterations, setAccuracy, setInterval, setIterations

Methods inherited from class java.lang.Object

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

Field Detail

MAX_ITERATIONS

public static final int MAX_ITERATIONS

Maximum number of iterations to perform before bailing out.

See Also:

Constant Field Values

Constructor Detail

RegulaFalsi

public RegulaFalsi(int iterations)

Creates this RegulaFalsi root finder using the supplied number of iterations.

Parameters:

iterations - The maximum number of iterations to find a root.

Throws:

IllegalArgumentException - When the supplied iterations <= 0.

RegulaFalsi

public RegulaFalsi(double accuracy)

Creates this RegulaFalsi root finder using the supplied accuracy.

Parameters:

accuracy - The accuracy of the found root.

Throws:

IllegalArgumentException - When the supplied accuracy <= 0.

Method Detail

findRoot

public double findRoot(SingleParameterFunction function,
                       double left,
                       double right)

Finds a root of the supplied function within the supplied interval [left, right] using the Regula Falsi method.

Specified by:

findRoot in interface RootFinderStrategy

Parameters:

function - The function for which a root should be found.

left - x value of the left side of the interval.
The y value, that is the value of function(left) should have a sign that is opposite to that of function(right).

right - x value of the right side of the interval.
The y value, that is the value of function(right) should have a sign that is opposite to that of function(left).

Returns:

A root of the supplied function within the supplied interval [left, right].

Throws:

IllegalArgumentException - When left equals right or when both function(left) and function(right) are of equal sign or when either function(left) or function(right) is "Not a Number".

NullPointerException - when the supplied function is null.