jsat.math.rootfinding

Interface RootFinder

All Superinterfaces:

java.io.Serializable

All Known Implementing Classes:

Bisection, RiddersMethod, Secant, Zeroin

public interface RootFinder
extends java.io.Serializable

This interface defines a general contract for the numerical computation of a root of a given function. A root of a function f is a point x for which f(x) = 0. A function may have any number of roots (including no roots).

Method Summary

Modifier and Type	Method and Description
int	guessesNeeded() Different root finding methods require different numbers of initial guesses.
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.

Method Detail

root

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. Only one variable may be altered at a time

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

pos - the index of the argument that will be allowed to alter in order to find the root. Starts from 0

args - the values to be passed to the function as arguments

Returns:

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

guessesNeeded

int guessesNeeded()

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.

Returns:

the number of initial guesses this root finding method needs