ros2_control::MovingAverageStatistics Class Reference

#include <statistics_types.hpp>

Public Types
using	StatisticData = libstatistics_collector::moving_average_statistics::StatisticData

Public Member Functions
double	get_average () const
double	get_max () const
double	get_min () const
double	get_standard_deviation () const
const StatisticData &	get_statistics_const_ptr () const
StatisticData	get_statistics () const
const double &	get_current_measurement_const_ptr () const
double	get_current_measurement () const
void	reset ()
void	reset_current_measurement ()
virtual void	add_measurement (const double item)
uint64_t	get_count () const

Detailed Description

A class for calculating moving average statistics. This operates in constant memory and constant time. Note: reset() must be called manually in order to start a new measurement window.

The statistics calculated are average, maximum, minimum, and standard deviation (population). All are calculated online without storing the observation data. Specifically, the average is a running sum and the variance is obtained by Welford's online algorithm (reference: https://en.wikipedia.org/wiki/Algorithms_for_calculating_variance#Welford%27s_online_algorithm) for standard deviation.

When statistics are not available, e.g. no observations have been made, NaNs are returned.

Member Function Documentation

add_measurement()

virtual void ros2_control::MovingAverageStatistics::add_measurement ( const double  item )

inlinevirtual

Observe a sample for the given window. The input item is used to calculate statistics. Note: any input values of NaN will be discarded and not added as a measurement.

Parameters

item	The item that was observed

get_average()

double ros2_control::MovingAverageStatistics::get_average ( ) const

inline

Returns the arithmetic mean of all data recorded. If no observations have been made, returns NaN.

Returns

The arithmetic mean of all data recorded, or NaN if the sample count is 0.

get_count()

uint64_t ros2_control::MovingAverageStatistics::get_count ( ) const

inline

Return the number of samples observed

Returns

the number of samples observed

get_current_measurement_const_ptr()

const double & ros2_control::MovingAverageStatistics::get_current_measurement_const_ptr ( ) const

inline

Get the current measurement value. This is the last value added to the statistics collector.

Returns

The current measurement value, or NaN if no measurements have been made.

get_max()

double ros2_control::MovingAverageStatistics::get_max ( ) const

inline

Returns the maximum value recorded. If size of list is zero, returns NaN.

Returns

The maximum value recorded, or NaN if size of data is zero.

get_min()

double ros2_control::MovingAverageStatistics::get_min ( ) const

inline

Returns the minimum value recorded. If size of list is zero, returns NaN.

Returns

The minimum value recorded, or NaN if size of data is zero.

get_standard_deviation()

double ros2_control::MovingAverageStatistics::get_standard_deviation ( ) const

inline

Returns the standard deviation (population) of all data recorded. If size of list is zero, returns NaN.

Variance is obtained by Welford's online algorithm, see https://en.wikipedia.org/wiki/Algorithms_for_calculating_variance#Welford%27s_online_algorithm

Returns

The standard deviation (population) of all data recorded, or NaN if size of data is zero.

get_statistics_const_ptr()

const StatisticData & ros2_control::MovingAverageStatistics::get_statistics_const_ptr ( ) const

inline

Return a StatisticData object, containing average, minimum, maximum, standard deviation (population), and sample count. For the case of no observations, the average, min, max, and standard deviation are NaN.

Returns

StatisticData object, containing average, minimum, maximum, standard deviation (population), and sample count.

reset()

void ros2_control::MovingAverageStatistics::reset ( )

inline

Reset all calculated values. Equivalent to a new window for a moving average.

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

• ros2_control/hardware_interface/include/hardware_interface/types/statistics_types.hpp