Factorial, gamma and related functions.

Functions
double	factln (double n)
	Log-factorial .
dvector	factln (const dvector &r)
	Log-factorial of an array.
double	gammln (double xx)
	Log gamma function.
dvector	gammln (const dvector &v)
	Log-Gamma of an array.
double	log_comb (double n, double k)
	Log of the binomial coefficent; i.e log of 'n choose k'.
dvector	log_comb (const dvector &n, const dvector &r)
	Log-binomial of two arrays.

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Function Documentation

double factln

(

double

n

)

Log-factorial .

Parameters:

n

a number

Returns:

log of the factorial

Definition at line 38 of file combc.cpp.

Referenced by log_comb().

dvector factln

(

const dvector &

r

)

Log-factorial of an array.

Parameters:

r

an array

Returns:

log of the factorial

Definition at line 137 of file combc.cpp.

double gammln

(

double

xx

)

Log gamma function.

Parameters:

xx

Returns:

The implementation of this algorithm was inspired by "Numerical Recipes in C", 2nd edition, Press, Teukolsky, Vetterling, Flannery, chapter 6

Definition at line 52 of file combc.cpp.

Referenced by beta(), betai(), dbeta(), density_negbinomial(), dgamma(), dinvgamma(), dmultinom(), dnbinom(), dpois(), dstudent_t(), dzinbinom(), factln(), gamma_density(), gammln(), gcf(), get_initial_u(), gser(), inv_cumd_gamma(), lnbeta(), log_density_negbinomial(), log_density_poisson(), log_gamma_density(), log_negbinomial_density(), negbinomial_density(), nllBeta(), nllDirichlet(), nllGamma(), nllInverseGamma(), nllMultiNomial(), nllNegativeBinomial(), nllPoisson(), and randpoisson().

dvector gammln

(

const dvector &

v

)

Log-Gamma of an array.

Parameters:

v

an array

Returns:

log of the factorial

Definition at line 119 of file combc.cpp.

double log_comb	(	double	n,
		double	k
	)

Log of the binomial coefficent; i.e log of 'n choose k'.

Parameters:

n	a number
k	a number

Returns:

Definition at line 27 of file combc.cpp.

Referenced by dbinom(), log_comb(), and nllBinomial().

dvector log_comb	(	const dvector &	n,
		const dvector &	r
	)

Log-binomial of two arrays.

Parameters:

n	an array
r	an array

Returns:

log of the binomial coefficent

Definition at line 77 of file combc.cpp.