de.jstacs.algorithms.optimization.termination
Class SmallDifferenceOfFunctionEvaluationsCondition

java.lang.Object
  de.jstacs.algorithms.optimization.termination.SmallDifferenceOfFunctionEvaluationsCondition

All Implemented Interfaces:

TerminationCondition

public class SmallDifferenceOfFunctionEvaluationsCondition
extends Object
implements TerminationCondition

This class implements a TerminationCondition that stops an optimization if the difference of the current and the last function evaluations will be small, i.e., .

Author:

Jens Keilwagen

Constructor Summary

SmallDifferenceOfFunctionEvaluationsCondition(double epsilon)
This constructor creates an instance that stops the optimization if the difference of the current and the last function evaluations is smaller than epsilon.

Method Summary

boolean

doNextIteration(int iteration, double f_last, double f_current, double[] gradient, double[] direction, double alpha, Time t) This method allows to decide whether to do another iteration in an optimization or not.

Methods inherited from class java.lang.Object

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

Constructor Detail

SmallDifferenceOfFunctionEvaluationsCondition

public SmallDifferenceOfFunctionEvaluationsCondition(double epsilon)

This constructor creates an instance that stops the optimization if the difference of the current and the last function evaluations is smaller than epsilon.

Parameters:

epsilon - the threshold for stopping, has to be non.negative

Method Detail

doNextIteration

public boolean doNextIteration(int iteration,
                               double f_last,
                               double f_current,
                               double[] gradient,
                               double[] direction,
                               double alpha,
                               Time t)

Description copied from interface: TerminationCondition

This method allows to decide whether to do another iteration in an optimization or not.

Specified by:

doNextIteration in interface TerminationCondition

Parameters:

iteration - the number of performed iterations

f_last - last value of the function

f_current - current value of the function

gradient - the gradient of the function

direction - the last direction of the optimization

alpha - the last step size

t - a time object measuring the time that has been elapsed in the optimization

Returns:

true if another iteration should be done