org.objectweb.fractal.jmx.julia.stat
Class ExponentialSmoothingStatController

java.lang.Object
  org.objectweb.fractal.jmx.julia.stat.BasicStatController
      org.objectweb.fractal.jmx.julia.stat.ExponentialSmoothingStatController

All Implemented Interfaces:

Initializable, StatController

public class ExponentialSmoothingStatController

extends BasicStatController

Extends BasicStatController with an exponential smoothing method for the rate computation. The rate values returned by this implementation are computed as follows:

            ST = (alpha * xT) + ((1 - alpha) * ST-1)
 

where:

• S_T: is the current smoothed rate value. It represents a weighted average of all past rate values returned by BasicStatController.
• alpha: is the smoothing constant. Its value must be in the interval [0-1] and can be fixed by initialize.
  If alpha equals 1, the rate values returned by this implementation are similar to the values returned by BasicStatController.
• x_T: is the current actual rate value returned by BasicStatController.
• S_T-1: is the previous smoothed rate value.

Version:

0.1

Field Summary

protected double

_alpha Smoothing constant (default value is 0.5).

Fields inherited from class org.objectweb.fractal.jmx.julia.stat.BasicStatController

_period

Constructor Summary

ExponentialSmoothingStatController()

Method Summary

double	getRateOfMethodCall() Gets the rate of method calls.
double	getRateOfMethodSuccess() Gets the rate of method calls that have "succeded".
void	initialize(Tree args) Initializes this object with the given arguments.
void	reset() Resets (to zero) the values returned by this controller.

Methods inherited from class org.objectweb.fractal.jmx.julia.stat.BasicStatController

getNumberOfMethodCall, getNumberOfMethodSuccess, statPostMethod, statPreMethod

Methods inherited from class java.lang.Object

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

Field Detail

_alpha

protected double _alpha

Smoothing constant (default value is 0.5).

Its value must be in the interval [0-1] and can be fixed by initialize.

Constructor Detail

ExponentialSmoothingStatController

public ExponentialSmoothingStatController()

Method Detail

initialize

public void initialize(Tree args)

Initializes this object with the given arguments. The first subtree (if any) must represent the value of period. The second subtree (if any) must represent the value of the smoothing constant.

Specified by:

initialize in interface Initializable

Overrides:

initialize in class BasicStatController

Parameters:

args - the arguments to be used to initialize this object.

Throws:

NumberFormatException - if the first subtree is not a valid string representation of a long value, or if the second subtree is not a valid string representation of a double value.

IllegalStateException - if the firts subtree does not represent a positive value or if the second subtree does not represent a value in the interval [0-1].

getRateOfMethodCall

public double getRateOfMethodCall()

Description copied from interface: StatController

Gets the rate of method calls.

Specified by:

getRateOfMethodCall in interface StatController

Overrides:

getRateOfMethodCall in class BasicStatController

getRateOfMethodSuccess

public double getRateOfMethodSuccess()

Description copied from interface: StatController

Gets the rate of method calls that have "succeded".

Specified by:

getRateOfMethodSuccess in interface StatController

Overrides:

getRateOfMethodSuccess in class BasicStatController

reset

public void reset()

Description copied from interface: StatController

Resets (to zero) the values returned by this controller.

Specified by:

reset in interface StatController

Overrides:

reset in class BasicStatController