std.internal.math.gammafunction

Implementation of the gamma and beta functions, and their integrals.

Based on the CEPHES math library, which is

Stephen L. Moshier (original C code). Conversion to D by Don Clugston

Functions 18

fnreal gammaStirling(real x)

fnreal igammaTemmeLarge(real a, real x)

fnreal gamma(real x)The Gamma function, (x)

fnreal logGamma(real x)Natural logarithm of gamma function.

fnreal sgnGamma(in real x)sgn((x))

private fnreal betaLarge(in real x, in real y)

fnreal beta(in real x, in real y)B(x,y)

fnreal betaIncomplete(real aa, real bb, real xx )Incomplete beta integral

fnreal betaIncompleteInv(real aa, real bb, real yy0 )Inverse of incomplete beta integral

fnreal betaDistExpansion1(real a, real b, real x )

fnreal betaDistExpansion2(real a, real b, real x )

fnreal betaDistPowerSeries(real a, real b, real x )

fnreal gammaIncomplete(real a, real x )Incomplete gamma integral and its complement

fnreal gammaIncompleteCompl(real a, real x )ditto

fnreal gammaIncompleteComplInv(real a, real p)Inverse of complemented incomplete gamma integral

fnreal digamma(real x)Digamma function

fnreal logmdigamma(real x)Log Minus Digamma function

fnreal logmdigammaInverse(real y)Inverse of the Log Minus Digamma function

enumvarSQRT2PI = 2.50662827463100050242E0L

varreal EULERGAMMA

varreal[8] GammaNumeratorCoeffs

varreal[9] GammaDenominatorCoeffs

varreal[9] GammaSmallCoeffs

varreal[9] GammaSmallNegCoeffs

varreal[7] logGammaStirlingCoeffs

varreal[7] logGammaNumerator

varreal[8] logGammaDenominator

enumvarBETA_BIG = 9.223372036854775808e18L

enumvarBETA_BIGINV = 1.084202172485504434007e-19L

varreal [7] Bn_n