514 double lcl_getLanczosSum(double fZ)  in lcl_getLanczosSum()  argument
551     if (fZ<=1.0)  in lcl_getLanczosSum()
557             fSumNum *= fZ;  in lcl_getLanczosSum()
559             fSumDenom *= fZ;  in lcl_getLanczosSum()
566         fZInv = 1/fZ;  in lcl_getLanczosSum()
583 double lcl_GetGammaHelper(double fZ)  in lcl_GetGammaHelper()  argument
585     double fGamma = lcl_getLanczosSum(fZ);  in lcl_GetGammaHelper()
587     double fZgHelp = fZ + fg - 0.5;  in lcl_GetGammaHelper()
589     double fHalfpower = pow( fZgHelp, fZ / 2 - 0.25);  in lcl_GetGammaHelper()
593     if (fZ <= 20.0 && fZ == ::rtl::math::approxFloor(fZ))  in lcl_GetGammaHelper()
601 double lcl_GetLogGammaHelper(double fZ)  in lcl_GetLogGammaHelper()  argument
604     double fZgHelp = fZ + fg - 0.5;  in lcl_GetLogGammaHelper()
605     return log( lcl_getLanczosSum(fZ)) + (fZ-0.5) * log(fZgHelp) - fZgHelp;  in lcl_GetLogGammaHelper()
609 double ScInterpreter::GetGamma(double fZ)  in GetGamma()  argument
615     if (fZ > fMaxGammaArgument)  in GetGamma()
621     if (fZ >= 1.0)  in GetGamma()
622         return lcl_GetGammaHelper(fZ);  in GetGamma()
624     if (fZ >= 0.5)  // shift to x>=1 using Gamma(x)=Gamma(x+1)/x  in GetGamma()
625         return lcl_GetGammaHelper(fZ+1) / fZ;  in GetGamma()
627     if (fZ >= -0.5) // shift to x>=1, might overflow  in GetGamma()
629         double fLogTest = lcl_GetLogGammaHelper(fZ+2) - log(fZ+1) - log( fabs(fZ));  in GetGamma()
635         return lcl_GetGammaHelper(fZ+2) / (fZ+1) / fZ;  in GetGamma()
639     double fLogDivisor = lcl_GetLogGammaHelper(1-fZ) + log( fabs( ::rtl::math::sin( F_PI*fZ)));  in GetGamma()
650     return exp( fLogPi - fLogDivisor) * ((::rtl::math::sin( F_PI*fZ) < 0.0) ? -1.0 : 1.0);  in GetGamma()
655 double ScInterpreter::GetLogGamma(double fZ)  in GetLogGamma()  argument
658     if (fZ >= fMaxGammaArgument)  in GetLogGamma()
659         return lcl_GetLogGammaHelper(fZ);  in GetLogGamma()
660     if (fZ >= 1.0)  in GetLogGamma()
661         return log(lcl_GetGammaHelper(fZ));  in GetLogGamma()
662     if (fZ >= 0.5)  in GetLogGamma()
663         return log( lcl_GetGammaHelper(fZ+1) / fZ);  in GetLogGamma()
664     return lcl_GetLogGammaHelper(fZ+2) - log(fZ+1) - log(fZ);  in GetLogGamma()