datan

Class MinCombined

java.lang.Object

datan.MinCombined

public final class MinCombined
extends java.lang.Object

A class determining the minimum of a function along a straight line in n-dimensional space according to combination the method of the golden section and of quadratic interpolation

Author:

Siegmund Brandt.

Constructor Summary

Constructors

Constructor and Description
MinCombined(double xa, double xb, DatanVector x0, DatanVector xdir, int nstep, double epsilon, DatanUserFunction muf)

Method Summary

Methods

Modifier and Type	Method and Description
int	getSteps()
double	getX()
double	getY()
boolean	hasConverged()

Methods inherited from class java.lang.Object

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

Constructor Detail

MinCombined

public MinCombined(double xa,
           double xb,
           DatanVector x0,
           DatanVector xdir,
           int nstep,
           double epsilon,
           DatanUserFunction muf)

Parameters:

x0 - point in n-space

xdir - direction in n-space. Straight line is given by x = x0 + a * xdir, where a is a running scalar variable.

xa - value corresponding to a point defining one end the interval comprising the minimum.

xb - value corresponding to a point defining the other end the interval comprising the minimum.

nstep - maximal step number; if a value <= 0 is used, then 1000 is taken instead.

epsilon - accuracy; if a value <= 0. is used, then 1,E-8 is taken instead.

muf - user function which must be an extension of the abstract class DatanUserFunction.

Method Detail

getX

public double getX()

Returns:

the postion of the minimum.

getY

public double getY()

Returns:

the function value at the minimum.

getSteps

public int getSteps()

Returns:

the number of iteration steps needed, -1 if iteration failed.

hasConverged

public boolean hasConverged()

Returns:

true if iteration successful, false otherwise.