net.sourceforge.webcompmath.functions
Class ZeroFinder

java.lang.Object
  net.sourceforge.webcompmath.functions.ZeroFinder

public class ZeroFinder
extends java.lang.Object

Description for ZeroFinder
ZeroFinder computes one zero of the continuous function func,
provided that the two starting values x1 and x2 satisfy:
func( x1 ) * func( x2 ) <= 0 .

Applications :

Determine one root of the continuous function func, if an
inclusion interval [x1, x2] is known for the root.

"Return values" :
= -1 No inclusion: func( x2 ) * func( x1 ) >0
= 0 Root has been found with ABS( f2 ) < funcERR
= 1 Break-off with ABS(xnew-xold ) < ABSERR + xnew * RELERR,
check functional value
= 2 Iteration limit reached
= 3 Improper input parameters
= 4 NaN encountered
getSolution() gives the solution if isSolved() returns true.
Constants used : ABSERR, RELERR, MACH_EPS, EPSROOT, ITERMAX

Author:

pkhg

Field Summary

protected double	ABSERROR Default value of absolute error bound
protected double	funcERR -1: no inclusion given 0: with abs( f( x )) <= Double.Min_Value 1: ABS( xnew-xold ) < ABSERROR + xnew * RELERROR 2: iterationlimit ITERMAX reached 3: improper function 4: NaN encountered at: x3;
protected Function	function The function, for which zeros are to be found ( should be continous!)
protected double	fX1in Interval ( left ) point
protected double	fX2in Interval ( right ) point
protected int	iter Iterations used
protected int	ITERMAX Default value of maximun number of iterations
protected double	RELERROR Default value of relative error bound
protected java.lang.String	resultOfIteration Description of kind of soulution
protected double	solution Place of a zero ( within precision )
protected boolean	solved Solution with given precision found or not
protected static double	ZERO Description of the Field

Constructor Summary

ZeroFinder()
Default constructor for the ZeroFinder object

ZeroFinder(Function inFunction)
The object with standard precision parameters

Method Summary

double	getAbsError() Gets the AbsError attribute of the ZeroFinder object
double	getFX1in() Gets the FX1in attribute of the ZeroFinder object
double	getFX2in() Gets the FX2in attribute of the ZeroFinder object
int	getIter() Gets the Iter attribute of the ZeroFinder object
int	getIterMax() Gets the IterMax attribute of the ZeroFinder object
double	getRelError() Gets the RelError attribute of the ZeroFinder object
java.lang.String	getResultOfIteration() Gets the ResultOfIteration attribute of the ZeroFinder object
double	getSolution() Gets the Solution attribute of the ZeroFinder object
boolean	isSolved() Gets the Solved attribute of the ZeroFinder object
static void	main(java.lang.String[] arg) To test ZeroFinder
void	setAbsError(double newAbsError) Sets the AbsError attribute of the ZeroFinder object
void	setFunction(Function newFunction) Sets the Function attribute of the ZeroFinder object
void	setIterMax(int maxiter) Sets the IterMax attribute of the ZeroFinder object
void	setRelError(double newRelError) Sets the RelError attribute of the ZeroFinder object
void	Solve(double x1in, double x2in) The 'Regula Falsi' extended ZeroFinder zero-finder:

Methods inherited from class java.lang.Object

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

Field Detail

function

protected Function function

The function, for which zeros are to be found ( should be continous!)

solved

protected boolean solved

Solution with given precision found or not

solution

protected double solution

Place of a zero ( within precision )

fX1in

protected double fX1in

Interval ( left ) point

fX2in

protected double fX2in

Interval ( right ) point

ITERMAX

protected int ITERMAX

Default value of maximun number of iterations

ABSERROR

protected double ABSERROR

Default value of absolute error bound

RELERROR

protected double RELERROR

Default value of relative error bound

resultOfIteration

protected java.lang.String resultOfIteration

Description of kind of soulution

funcERR

protected double funcERR

     
    -1: no inclusion given
    0: with abs( f( x )) <= Double.Min_Value
    1: ABS( xnew-xold ) < ABSERROR + xnew * RELERROR
    2: iterationlimit   ITERMAX   reached
    3: improper function
    4: NaN encountered at:  x3;
  
 

iter

protected int iter

Iterations used

ZERO

protected static double ZERO

Description of the Field

Constructor Detail

ZeroFinder

public ZeroFinder()

Default constructor for the ZeroFinder object

ZeroFinder

public ZeroFinder(Function inFunction)

The object with standard precision parameters

ITERMAX = 20;

ABSERROR = 1.0E-6D;

RELERROR = 1.0E-6D;

funcERR = Double.MIN_VALUE;

Parameters:

inFunction - a Function Object e.g. from TaylorInput

Method Detail

setRelError

public void setRelError(double newRelError)

Sets the RelError attribute of the ZeroFinder object

Parameters:

newRelError - The new RelError value

setAbsError

public void setAbsError(double newAbsError)

Sets the AbsError attribute of the ZeroFinder object

Parameters:

newAbsError - The new AbsError value

setIterMax

public void setIterMax(int maxiter)

Sets the IterMax attribute of the ZeroFinder object

Parameters:

maxiter - The new IterMax value

setFunction

public void setFunction(Function newFunction)

Sets the Function attribute of the ZeroFinder object

Parameters:

newFunction - The new Function value

getSolution

public double getSolution()

Gets the Solution attribute of the ZeroFinder object

Returns:

The Solution value

isSolved

public boolean isSolved()

Gets the Solved attribute of the ZeroFinder object

Returns:

The Solved value

getRelError

public double getRelError()

Gets the RelError attribute of the ZeroFinder object

Returns:

The RelError value

getFX1in

public double getFX1in()

Gets the FX1in attribute of the ZeroFinder object

Returns:

The FX1in value

getFX2in

public double getFX2in()

Gets the FX2in attribute of the ZeroFinder object

Returns:

The FX2in value

getAbsError

public double getAbsError()

Gets the AbsError attribute of the ZeroFinder object

Returns:

The AbsError value

getIter

public int getIter()

Gets the Iter attribute of the ZeroFinder object

Returns:

The Iter value

getIterMax

public int getIterMax()

Gets the IterMax attribute of the ZeroFinder object

Returns:

The IterMax value

getResultOfIteration

public java.lang.String getResultOfIteration()

Gets the ResultOfIteration attribute of the ZeroFinder object

Returns:

The ResultOfIteration value

Solve

public void Solve(double x1in,
                  double x2in)

The 'Regula Falsi' extended ZeroFinder zero-finder:

Parameters:

x1in - left point of interval

x2in - right point of interval

main

public static void main(java.lang.String[] arg)

To test ZeroFinder

Parameters:

arg - ( not used )