FilterDoubleExponentialSmoothing provides an weighted running average filter More...

#include <Filter.h>

Inheritance diagram for alvar::FilterDoubleExponentialSmoothing:

Public Member Functions
	FilterDoubleExponentialSmoothing (double _alpha=0.5, double _gamma=1.0)

double	getGamma ()

virtual double	next (double y)
	Update the value. All inherited classes need to update value in next(). More...

double	operator= (double _value)

void	setGamma (double _gamma)

Public Member Functions inherited from alvar::FilterRunningAverage
	FilterRunningAverage (double _alpha=0.5)

double	getAlpha ()

double	operator= (double _value)

virtual void	reset ()
	Reset the filter state. More...

void	setAlpha (double _alpha)

Public Member Functions inherited from alvar::Filter
	Filter ()
	Constructor. More...

double	get () const
	Get the latest value. More...

	operator double ()
	Get the latest value. More...

Protected Attributes
double	gamma

double	slope

Protected Attributes inherited from alvar::FilterRunningAverage
double	alpha

bool	breset

Protected Attributes inherited from alvar::Filter
double	value

Detailed Description

FilterDoubleExponentialSmoothing provides an weighted running average filter

The FilterDoubleExponentialSmoothing calculates a simple running average for both the average and slope using the weight values alpha and gamma.

value = ((1.0-alpha) * (value + slope)) + (alpha * (double)y);

slope = ((1.0-gamma) * (slope)) + (gamma * (value - value_prev));

If the weight values (alpha , gamma) are larger (near 1.0) the formulas react faster for changes and if they are near 0.0 then the reaction is slower. The weight values alpha and gamma may be set in the constructor or with setAlpha() and setGamma() .

Examples:: SampleFilter.cpp.

Definition at line 187 of file Filter.h.

Constructor & Destructor Documentation

alvar::FilterDoubleExponentialSmoothing::FilterDoubleExponentialSmoothing	(	double	_alpha = `0.5`,
		double	_gamma = `1.0`
	)

inline

Definition at line 192 of file Filter.h.

Member Function Documentation

double alvar::FilterDoubleExponentialSmoothing::getGamma ( )

inline

Definition at line 196 of file Filter.h.

double alvar::FilterDoubleExponentialSmoothing::next ( double y )

virtual

Update the value. All inherited classes need to update value in next().

Reimplemented from alvar::FilterRunningAverage.

Examples:: SampleFilter.cpp.

Definition at line 99 of file Filter.cpp.

double alvar::FilterDoubleExponentialSmoothing::operator= ( double _value )

inline

Definition at line 197 of file Filter.h.

void alvar::FilterDoubleExponentialSmoothing::setGamma ( double _gamma )

inline

Definition at line 195 of file Filter.h.

Member Data Documentation

double alvar::FilterDoubleExponentialSmoothing::gamma

protected

Definition at line 189 of file Filter.h.

double alvar::FilterDoubleExponentialSmoothing::slope

protected

Definition at line 190 of file Filter.h.

The documentation for this class was generated from the following files:

Public Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation