jsat.math.rootfinding

Class Zeroin

java.lang.Object

jsat.math.rootfinding.Zeroin

All Implemented Interfaces:

java.io.Serializable, RootFinder

public class Zeroin
extends java.lang.Object
implements RootFinder

This class provides an implementation of the popular ZeroIn root finder.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
Zeroin()

Method Summary

Modifier and Type	Method and Description
int	guessesNeeded() Different root finding methods require different numbers of initial guesses.
static double	root(double eps, double a, double b, Function1D f) Performs root finding on the function f.
static double	root(double a, double b, Function1D f) Performs root finding on the function f.
double	root(double eps, int maxIterations, double[] initialGuesses, Function1D f) Attempts to numerical compute the root of a given function, such that f(args) = 0.
static double	root(double eps, int maxIterations, double a, double b, Function1D f) Performs root finding on the function f.

Methods inherited from class java.lang.Object

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

Constructor Detail

Zeroin

public Zeroin()

Method Detail

root

public static double root(double a,
                          double b,
                          Function1D f)

Performs root finding on the function f.

Parameters:

a - the left bound on the root (i.e., f(a) < 0)

b - the right bound on the root (i.e., f(b) > 0)

f - the function to find the root of

Returns:

the value of variable pos that produces a zero value output

root

public static double root(double eps,
                          double a,
                          double b,
                          Function1D f)

Performs root finding on the function f.

Parameters:

eps - the desired accuracy of the result

a - the left bound on the root (i.e., f(a) < 0)

b - the right bound on the root (i.e., f(b) > 0)

f - the function to find the root of

Returns:

the value of variable pos that produces a zero value output

root

public static double root(double eps,
                          int maxIterations,
                          double a,
                          double b,
                          Function1D f)

Performs root finding on the function f.

Parameters:

eps - the desired accuracy of the result

maxIterations - the maximum number of iterations to perform

a - the left bound on the root (i.e., f(a) < 0)

b - the right bound on the root (i.e., f(b) > 0)

f - the function to find the root of

Returns:

the value of variable pos that produces a zero value output

root

public double root(double eps,
                   int maxIterations,
                   double[] initialGuesses,
                   Function1D f)

Description copied from interface: RootFinder

Attempts to numerical compute the root of a given function, such that f(args) = 0. Only one variable may be altered at a time

Specified by:

root in interface RootFinder

Parameters:

eps - the accuracy desired for the solution

maxIterations - the maximum number of steps allowed before forcing a return of the current solution.

initialGuesses - an array containing the initial guess values

f - the function to find the root of

Returns:

the value of the variable at the index pos that makes the function return 0

guessesNeeded

public int guessesNeeded()

Description copied from interface: RootFinder

Different root finding methods require different numbers of initial guesses. Some root finding methods require 2 guesses, each with values of opposite sign so that they bracket the root. Others just need any 2 initial guesses sufficiently close to the root. This method simply returns the number of guesses that are needed.

Specified by:

guessesNeeded in interface RootFinder

Returns:

the number of initial guesses this root finding method needs