utl::BinomialCoefficients Class Reference

Calculates binomial coefficients and caches the results. More...

#include "utl/BinomialCoefficients.h"

Inheritance diagram for utl::BinomialCoefficients:

Public Member Functions
	BinomialCoefficients (const int initialN=3)
double	operator() (const int n, const int k)

Public Attributes
static BinomialCoefficients &return	instance

Private Member Functions
void	Generate (const int n)
double &	GetUnchecked (const int n, const int k)

Private Attributes
std::vector< double >	fCoefficients
int	fMaxN

Detailed Description

Calculates binomial coefficients and caches the results.

Call to the class' operator(n, k) is equivalent to binomial coefficient .

Due to rounding errors for the explicit formula with factorials (division of large numbers) this generator is using the Pascal triangle relations instead, i.e.

where only addition of moderate sized numbers can be maintained even for fairly large n.

Usage:

BinomialCoefficients& binomial = BinomialCoefficients::GetInstance();
const double b_4_2 = binomial(4, 2);

Author

Darko Veberic

Date

05 Sep 2009

Definition at line 38 of file BinomialCoefficients.h.

Constructor & Destructor Documentation

utl::BinomialCoefficients::BinomialCoefficients ( const int  initialN = 3 )

inline

Definition at line 40 of file BinomialCoefficients.h.

References Generate().

Member Function Documentation

void BinomialCoefficients::Generate ( const int  n )

private

Definition at line 8 of file BinomialCoefficients.cc.

References fCoefficients, fMaxN, GetUnchecked(), and WARNING.

Referenced by BinomialCoefficients(), and operator()().

double& utl::BinomialCoefficients::GetUnchecked ( const int  n, const int  k  )

inlineprivate

Definition at line 54 of file BinomialCoefficients.h.

References fCoefficients.

Referenced by Generate(), and operator()().

double utl::BinomialCoefficients::operator() ( const int  n, const int  k  )

inline

Definition at line 44 of file BinomialCoefficients.h.

References fMaxN, Generate(), and GetUnchecked().

Member Data Documentation

std::vector<double> utl::BinomialCoefficients::fCoefficients

private

Definition at line 60 of file BinomialCoefficients.h.

Referenced by Generate(), and GetUnchecked().

int utl::BinomialCoefficients::fMaxN

private

Definition at line 59 of file BinomialCoefficients.h.

Referenced by Generate(), and operator()().

BinomialCoefficients & return utl::Singleton< BinomialCoefficients >::instance

inherited

Definition at line 44 of file Singleton.h.

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

• BinomialCoefficients.h
• BinomialCoefficients.cc