math.numerics
Class FindRoot

java.lang.Object
  |
  +--math.numerics.FindRoot

public class FindRoot

extends java.lang.Object

The class FindRoot is used to solve a system of equations for a root nearby a user-supplied initial guess. This uses simple newton's method. Future releases will couple newton's method with line searches and allow for n-dimensional systems.

Since:

JDK1.1

Author:

Eric Wright

, for the Mathematical Visualization project for the Department of Applied Mathematics, University of Colorado at Boulder

Constructor Summary

FindRoot(FunctionList f, VariableSet v, double[] ig)

FindRoot(FunctionList f, VariableSet v, double[] ig, int maxIts, double eps)

FindRoot(Function f, Variable var, double init)

Method Summary

int	getDimension() Get the value of dimension.
double[]	getInitGuesses() Get the value of initGuesses.
double[][]	newton() This method performins the Newton iteration.
void	setDimension(int v) Set the value of dimension.
void	setFunctions(FunctionList f)
void	setInitGuesses(double[] v) Set the value of initGuesses.

Methods inherited from class java.lang.Object

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

Constructor Detail

FindRoot

public FindRoot(FunctionList f,
                VariableSet v,
                double[] ig,
                int maxIts,
                double eps)

FindRoot

public FindRoot(FunctionList f,
                VariableSet v,
                double[] ig)

FindRoot

public FindRoot(Function f,
                Variable var,
                double init)

Method Detail

newton

public double[][] newton()
                  throws VariableUndefinedException,
                         UnacceptableVariableException,
                         SingularJacobianException,
                         ExcessiveIterationsException

This method performins the Newton iteration.

Returns:

double[][] array containing the coordinates of the root found by newton's method.

Throws:

VariableUndefinedException - for undefined variables

UnacceptableVariableException - for variables using illegal characers

SingularJacobianException - is thrown whenever jacobian determinant of system vanishes.

ExcessiveIterationException - is thrown whenever a specified number of iterations occur before newton converges to a root within the prescribed level of tolerance.

ExcessiveIterationsException

setFunctions

public void setFunctions(FunctionList f)

getDimension

public int getDimension()

Get the value of dimension.

Returns:

Value of dimension.

setDimension

public void setDimension(int v)

Set the value of dimension.

Parameters:

v - Value to assign to dimension.

getInitGuesses

public double[] getInitGuesses()

Get the value of initGuesses.

Returns:

Value of initGuesses.

setInitGuesses

public void setInitGuesses(double[] v)

Set the value of initGuesses.

Parameters:

v - Value to assign to initGuesses.