Collaboration diagram for statistics::stats_computer1< T >:

[legend]

Public Member Functions
void	new_val (T x)

double	mean () const

double	variance () const

double	std () const

Private Attributes
unsigned int	n = 0

double	Ex

double	Ex2

T	K

Friends
std::istream &	operator>> (std::istream &input, stats_computer1 &stat)

Detailed Description

template<typename T>
class statistics::stats_computer1< T >

continuous mean and variance computance using first value as an approximation for the mean. If the first number is much far form the mean, the algorithm becomes very inaccurate to compute variance and standard deviation.

Definition at line 27 of file realtime_stats.cpp.

Member Function Documentation

◆ mean()

template<typename T >

double statistics::stats_computer1< T >::mean ( ) const

inline

return sample mean computed till last sample

Definition at line 42 of file realtime_stats.cpp.

42{ return K + Ex / n; }

◆ new_val()

template<typename T >

void statistics::stats_computer1< T >::new_val ( T x )

inline

Constructor

Parameters

[in] x new data sample

Definition at line 32 of file realtime_stats.cpp.

                      {
        if (n == 0)
            K = x;
        n++;
        T tmp = x - K;
        Ex += tmp;
        Ex2 += static_cast<double>(tmp) * tmp;
    }

◆ std()

template<typename T >

double statistics::stats_computer1< T >::std ( ) const

inline

return sample standard deviation computed till last sample

Definition at line 48 of file realtime_stats.cpp.

48{ return std::sqrt(this->variance()); }

statistics::stats_computer1::variance

double variance() const

Definition realtime_stats.cpp:45

◆ variance()

template<typename T >

double statistics::stats_computer1< T >::variance ( ) const

inline

return data variance computed till last sample

Definition at line 45 of file realtime_stats.cpp.

45{ return (Ex2 - (Ex * Ex) / n) / (n - 1); }

Friends And Related Symbol Documentation

◆ operator>>

template<typename T >

std::istream & operator>>	(	std::istream &	input,
		stats_computer1< T > &	stat )

friend

short-hand operator to read new sample from input stream
e.g.: std::cin >> stats1;

Definition at line 53 of file realtime_stats.cpp.

                                                           {
        T val;
        input >> val;
        stat.new_val(val);
        return input;
    }