nAverager Class Reference

class responsible for calculating averages More...

#include <nNetwork.h>

List of all members.

Public Member Functions
	nAverager ()
	constructor
	~nAverager ()
	destructor
REAL	GetAverage () const
	returns the average value
REAL	GetDataVariance () const
	returns the variance of the data ( average of (value-average)^2 )
REAL	GetAverageVariance () const
	returns the expected variance of the returned average
void	Timestep (REAL decay)
	lets all values decay, so they can be replaced by new ones
void	Add (REAL value, REAL weight=1)
	adds a value to the average
void	Reset ()
	resets average to zero
std::istream &	operator<< (std::istream &stream)
	read operator
std::ostream &	operator>> (std::ostream &stream) const
	write operator
Private Attributes
REAL	weight_
	the total statistical weight
REAL	sum_
	the total sum of value*weight
REAL	sumSquared_
	the total sum of value*value*weight
REAL	weightSquared_
	the sum of all weights, squared

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Detailed Description

class responsible for calculating averages

Definition at line 241 of file nNetwork.h.

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Constructor & Destructor Documentation

nAverager::nAverager

(

void

)

constructor

Definition at line 3596 of file nNetwork.cpp.

        : weight_(0), sum_(0), sumSquared_(0), weightSquared_(0)

nAverager::~nAverager

(

void

)

destructor

Definition at line 3610 of file nNetwork.cpp.

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Member Function Documentation

REAL nAverager::GetAverage

(

void

)

const

returns the average value

Returns:

the average value over the last time

Definition at line 3679 of file nNetwork.cpp.

Referenced by eTimer::AverageFPS(), eTimer::AverageFrameTime(), eTimer::IsSynced(), eTimer::Reset(), and eTimer::SyncTime().

{
    if ( weight_ > 0 )
        return sum_ / weight_;

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REAL nAverager::GetDataVariance

(

void

)

const

returns the variance of the data ( average of (value-average)^2 )

Returns:

the average recent variance in the incoming data

Definition at line 3697 of file nNetwork.cpp.

Referenced by GameLoop(), and gCycleMovement::TimestepCore().

{
    if ( weight_ > 0 )
    {
        REAL average       = sum_ / weight_;
        REAL averageSquare = sumSquared_ / weight_;
        REAL ret = averageSquare - average * average;
        if ( ret < 0 )
            ret = 0;
        return ret;
    }

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REAL nAverager::GetAverageVariance

(

void

)

const

returns the expected variance of the returned average

Returns:

the expected variance of the return value of GetAverage()

Definition at line 3722 of file nNetwork.cpp.

Referenced by eTimer::IsSynced(), eTimer::ReadSync(), sn_GetTimeout(), and eTimer::SyncTime().

{
    if ( weight_ > 0 )
    {
        REAL square = weight_ * weight_;

        REAL denominator = square - weightSquared_;
        REAL numerator = GetDataVariance() * weightSquared_;
        if ( denominator > numerator * 1E-30 )
        {
            return numerator/denominator;
        }
        else
            return 1E+30;
    }

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void nAverager::Timestep

(

REAL

decay

)

lets all values decay, so they can be replaced by new ones

Parameters:

decay

decay factor 0 .. infinity; larger values lead to more decay.

Definition at line 3624 of file nNetwork.cpp.

Referenced by eTimer::ReadSync(), and eTimer::SyncTime().

{
    REAL factor = 1/(1+decay);

    // pretend all data so far was collected with a weight of the original weight multiplied by factor
    weight_        *= factor;
    sum_           *= factor;

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void nAverager::Add	(	REAL	value,
		REAL	weight = 1
	)

adds a value to the average

Parameters:

	value	the value to add
	weight	its statistical weight (importance compared to other values)

Definition at line 3646 of file nNetwork.cpp.

Referenced by eTimer::eTimer(), eTimer::ReadSync(), eTimer::Reset(), and eTimer::SyncTime().

{
    tASSERT( weight >= 0 );
    weight_        += weight;
    sum_           += weight * value;

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void nAverager::Reset

(

void

)

resets average to zero

Definition at line 3664 of file nNetwork.cpp.

Referenced by eTimer::eTimer(), eTimer::ReadSync(), and eTimer::Reset().

{

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std::istream & nAverager::operator<<

(

std::istream &

stream

)

read operator

Parameters:

stream

stream to read from

Returns:

stream for chaining

Definition at line 3752 of file nNetwork.cpp.

{
    char c;
    stream >> c;
    tASSERT( c == '(' );

    stream >> weight_ >> sum_ >> sumSquared_ >> weightSquared_;

    stream >> c;
    tASSERT( c == ')' );

std::ostream & nAverager::operator>>

(

std::ostream &

stream

)

const

write operator

Parameters:

stream

stream to write to

Returns:

stream for chaining

Definition at line 3777 of file nNetwork.cpp.

{
    stream << '(' << weight_ << ' ' << sum_  << ' ' << sumSquared_  << ' ' << weightSquared_  << ')';

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Member Data Documentation

REAL nAverager::weight_ [private]

the total statistical weight

Definition at line 256 of file nNetwork.h.

REAL nAverager::sum_ [private]

the total sum of value*weight

Definition at line 257 of file nNetwork.h.

REAL nAverager::sumSquared_ [private]

the total sum of value*value*weight

Definition at line 258 of file nNetwork.h.

REAL nAverager::weightSquared_ [private]

the sum of all weights, squared

Definition at line 259 of file nNetwork.h.

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

• src/network/nNetwork.h
• src/network/nNetwork.cpp

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