waveblocks::math::KahanSum< T > Class Template Reference

The Kahan's algorithm achieves O(1) error growth for summing N numbers. More...

#include <kahan_sum.hpp>

Public Member Functions
	KahanSum ()=default
	compiler-generated default constructor More...
	KahanSum (const T &zero)
	A zero initializing constructor for types that cannot provide a default constructor. More...
	KahanSum (const KahanSum< T > &that)=default
	compiler-generated copy constructor More...
KahanSum &	operator= (const KahanSum< T > &that)=default
	compiler-generated copy assignment operator More...
KahanSum &	operator+= (const T &summand)
	adds a number More...
const T &	operator() () const
	retrieves accumulated sum. More...

Private Attributes
T	sum_
T	c_
T	y_
T	t_

Detailed Description

template<class T>
class waveblocks::math::KahanSum< T >

The Kahan's algorithm achieves O(1) error growth for summing N numbers.

This implementation works for every type that satisfies following requirements:

• copy constructor
• copy assignment operator
• binary plus operator that performs element-wise addition
• binary minus operator that performs element-wise subtraction

Template Parameters

T	type of summands

Constructor & Destructor Documentation

template<class T>

waveblocks::math::KahanSum< T >::KahanSum ( )

default

compiler-generated default constructor

Be aware that this constructor fails on summand types that cannot provide a default constructor like dynamically sized arrays/matrices.

See also

KahanSum::KahanSum(const T&)

template<class T>

waveblocks::math::KahanSum< T >::KahanSum ( const T &  zero )

inline

A zero initializing constructor for types that cannot provide a default constructor.

A noteable example is a dynamically sized matrix.

Parameters

[in]

zero

initialized zero value as a template

template<class T>

waveblocks::math::KahanSum< T >::KahanSum ( const KahanSum< T > &  that )

default

compiler-generated copy constructor

Member Function Documentation

template<class T>

const T& waveblocks::math::KahanSum< T >::operator() ( ) const

inline

retrieves accumulated sum.

Returns

accumulated sum

template<class T>

KahanSum& waveblocks::math::KahanSum< T >::operator+= ( const T &  summand )

inline

adds a number

Parameters

[in]

summand

summand

template<class T>

KahanSum& waveblocks::math::KahanSum< T >::operator= ( const KahanSum< T > &  that )

default

compiler-generated copy assignment operator

Member Data Documentation

template<class T>

T waveblocks::math::KahanSum< T >::c_

private

A running compensation for lost low-order bits.

template<class T>

T waveblocks::math::KahanSum< T >::sum_

private

Accumulated sum.

template<class T>

T waveblocks::math::KahanSum< T >::t_

private

template<class T>

T waveblocks::math::KahanSum< T >::y_

private

Preallocated temporary variables

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

• /userdata/raoulb/LWB/libwaveblocks/waveblocks/math/kahan_sum.hpp