jvx.numeric

Class PnConjugateGradient

java.lang.Object

jvx.numeric.PnConjugateGradient

All Implemented Interfaces:

java.io.Serializable

public class PnConjugateGradient
extends java.lang.Object
implements java.io.Serializable

Minimize functionals using conjugate gradient method.

See Also:

Serialized Form

Author:

Numerical Recipes, changed to Java and adapted by Konrad Polthier

Version:

30.04.06, 1.10 revised (kp) Max number of iterations is now a configurable non-static variable.
00.00.98, 1.00 created (kp)

Constructor Summary

Constructors

Constructor and Description
PnConjugateGradient()

Method Summary

Modifier and Type	Method and Description
double	dfrprmn(PdVector p, double fTol, PnFunction func) Perform several energy minimization steps using a conjugate gradient method.
int	getMaxNumIterations() Get maximal number of allowed iterations in dfrprmn.
int	getNumIterations() Get number of used iterations in last call of dfrprmn.
boolean	isStopped() Get maximal number of allowed iterations in dfrprmn.
void	setMaxNumIterations(int num) Set maximal number of allowed iterations in dfrprmn.
void	setStopped(boolean bStopped) Set maximal number of allowed iterations in dfrprmn.

Methods inherited from class java.lang.Object

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

Constructor Detail

PnConjugateGradient

public PnConjugateGradient()

Method Detail

getMaxNumIterations

public int getMaxNumIterations()

Get maximal number of allowed iterations in dfrprmn. If max number of iteration is reached then dfrprmn stops and returns.

Since:

JavaView 3.96.009

Version:

30.04.06, 1.00 created (kp)

setMaxNumIterations

public void setMaxNumIterations(int num)

Set maximal number of allowed iterations in dfrprmn. If max number of iteration is reached then dfrprmn stops and returns.

Since:

JavaView 3.96.009

Version:

30.04.06, 1.00 created (kp)

getNumIterations

public int getNumIterations()

Get number of used iterations in last call of dfrprmn. Return -1 if no iteration performed yet.

Version:

30.04.06, 1.10 revised (kp) Return value changed to -1 if not run yet.

isStopped

public boolean isStopped()

Get maximal number of allowed iterations in dfrprmn. If max number of iteration is reached then dfrprmn stops and returns.

Since:

JavaView 3.96.009

Version:

30.04.06, 1.00 created (kp)

setStopped

public void setStopped(boolean bStopped)

Set maximal number of allowed iterations in dfrprmn. If max number of iteration is reached then dfrprmn stops and returns.

Since:

JavaView 3.96.009

Version:

30.04.06, 1.00 created (kp)

dfrprmn

public double dfrprmn(PdVector p,
                      double fTol,
                      PnFunction func)

Perform several energy minimization steps using a conjugate gradient method. The set of variables and the energy are given as parameters.

Maximal number of steps is bounded by getMaxNumIterations which can be adjusted before calling this methods.

If more iterations than getMaxNumIterations are needed until the stop criteria is reached then the method stops and returns with a warning. In this case the resulting vector does not represent a minima but the current state of the minimization process, and therefore can be used as initial value for another call of this method.

Parameters:

p - vector with variable data, will be changed.

fTol - relative difference of energy used as stop criteria

func - function to be minimized

Returns:

function value at minimum

See Also:

setMaxNumIterations(int)