ExponentialMovingAverage Class Reference

#include <moving_average.h>

Inheritance diagram for ExponentialMovingAverage:

Public Member Functions
	ExponentialMovingAverage (int buffer_size)
	ExponentialMovingAverage (int buffer_size, double starting_value)
void	add_entry (double n) override
double	get_value () const override
int	get_size ()

Detailed Description

ExponentialMovingAverage

An exponential moving average is a way of smoothing out noisy data. For many sensor readings, the noise is roughly symmetric around the actual value. This means that if you collect enough samples those that are too high are cancelled out by the samples that are too low leaving the real value.

A simple mobing average lags significantly with time as it has to counteract old samples. An exponential moving average keeps more up to date by weighting newer readings higher than older readings so it is more up to date while also still smoothed.

The ExponentialMovingAverage class provides an simple interface to do this smoothing from our noisy sensor values.

Constructor & Destructor Documentation

ExponentialMovingAverage() [1/2]

ExponentialMovingAverage::ExponentialMovingAverage

(

int

buffer_size

)

Create a moving average calculator with 0 as the default value

Parameters

buffer_size

The size of the buffer. The number of samples that constitute a valid reading

ExponentialMovingAverage() [2/2]

ExponentialMovingAverage::ExponentialMovingAverage	(	int	buffer_size,
		double	starting_value )

Create a moving average calculator with a specified default value

Parameters

buffer_size	The size of the buffer. The number of samples that constitute a valid reading
starting_value	The value that the average will be before any data is added

Member Function Documentation

add_entry()

void ExponentialMovingAverage::add_entry ( double n )

overridevirtual

Add a reading to the buffer Before: [ 1 1 2 2 3 3] => 2 ^ After: [ 2 1 2 2 3 3] => 2.16 ^

Parameters

n	the sample that will be added to the moving average.

Implements Filter.

get_size()

int ExponentialMovingAverage::get_size

(

)

How many samples the average is made from

Returns

the number of samples used to calculate this average

get_value()

double ExponentialMovingAverage::get_value ( ) const

overridevirtual

Returns the average based off of all the samples collected so far

Returns

the calculated average. sum(samples)/numsamples

How many samples the average is made from

Returns

the number of samples used to calculate this average

Implements Filter.

---

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

• moving_average.h
• moving_average.cpp