Statistic Class Reference

#include <xstatistics.h>

Public Member Functions
void	add (const float)
float	average () const
void	clear ()
uint32_t	count () const
float	maximum () const
float	mean () const
float	minimum () const
float	pop_stdev () const
	Statistic ()
float	sum () const
float	unbiased_stdev () const
float	variance () const

Protected Attributes
uint32_t	_cnt
float	_max
float	_min
float	_ssqdif
float	_sum

Detailed Description

Definition at line 46 of file xstatistics.h.

Constructor & Destructor Documentation

Statistic()

Statistic::Statistic

(

)

Definition at line 3 of file xstatistics.cpp.

{
    clear();
}

Member Function Documentation

add()

void Statistic::add

(

const float

value

)

Definition at line 23 of file xstatistics.cpp.

{
    if (_cnt == 0)
    {
        _min = value;
        _max = value;
    }
    else
    {
        if (value < _min)
            _min = value;
        else if (value > _max)
            _max = value;
    }
    _sum += value;
    _cnt++;
 
#ifdef STAT_USE_STDEV
    if (_cnt > 1)
    {
        float _store = (_sum / _cnt - value);
        _ssqdif = _ssqdif + _cnt * _store * _store / (_cnt - 1);
        // ~10% faster but limits the amount of samples to 65K as _cnt*_cnt overflows
        // float _store = _sum - _cnt * value;
        // _ssqdif = _ssqdif + _store * _store / (_cnt*_cnt - _cnt);
    }
#endif
}

average()

float Statistic::average

(

)

const

Definition at line 53 of file xstatistics.cpp.

{
    if (_cnt == 0)
        return NAN; // original code returned 0
    return _sum / _cnt;
}

clear()

void Statistic::clear

(

)

Definition at line 9 of file xstatistics.cpp.

{
    _cnt = 0;
    _sum = 0;
    _min = 0;
    _max = 0;
#ifdef STAT_USE_STDEV
    _ssqdif = 0.0; // not _ssq but sum of square differences
    // which is SUM(from i = 1 to N) of
    // (f(i)-_ave_N)**2
#endif
}

count()

uint32_t Statistic::count ( ) const

inline

Definition at line 54 of file xstatistics.h.

{ return _cnt; }; // zero if empty

maximum()

float Statistic::maximum ( ) const

inline

Definition at line 57 of file xstatistics.h.

{ return _max; };  // zero if empty

mean()

float Statistic::mean

(

)

const

Definition at line 71 of file xstatistics.cpp.

{
    if (_cnt == 0)
        return NAN; // otherwise DIV0 error
    return this->sum() / _cnt;
}

minimum()

float Statistic::minimum ( ) const

inline

Definition at line 56 of file xstatistics.h.

{ return _min; };  // zero if empty

pop_stdev()

float Statistic::pop_stdev

(

)

const

Definition at line 78 of file xstatistics.cpp.

{
    if (_cnt == 0)
        return NAN; // otherwise DIV0 error
    return sqrt(_ssqdif / _cnt);
}

sum()

float Statistic::sum ( ) const

inline

Definition at line 55 of file xstatistics.h.

{ return _sum; };      // zero if empty

unbiased_stdev()

float Statistic::unbiased_stdev

(

)

const

Definition at line 85 of file xstatistics.cpp.

{
    if (_cnt < 2)
        return NAN; // otherwise DIV0 error
    return sqrt(_ssqdif / (_cnt - 1));
}

variance()

float Statistic::variance

(

)

const

Definition at line 64 of file xstatistics.cpp.

{
    if (_cnt == 0)
        return NAN; // otherwise DIV0 error
    return _ssqdif / _cnt;
}

Member Data Documentation

_cnt

uint32_t Statistic::_cnt

protected

Definition at line 68 of file xstatistics.h.

_max

float Statistic::_max

protected

Definition at line 71 of file xstatistics.h.

_min

float Statistic::_min

protected

Definition at line 70 of file xstatistics.h.

_ssqdif

float Statistic::_ssqdif

protected

Definition at line 73 of file xstatistics.h.

_sum

float Statistic::_sum

protected

Definition at line 69 of file xstatistics.h.

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

• xstatistics.h
• xstatistics.cpp