Gami Gami_sub Gamic Gamic_sub Gamit Gamit_sub Gammap Gammap_sub Gammapd Gammapd_sub Gammapi Gammapi_sub Gammapia Gammapia_sub Gammaq Gammaq_sub Gammaqi Gammaqi_sub Gammaqia Gammaqia_sub

Gammapd_sub() Sub Gammapd_sub ( Ret As  Double, A As  Double, X As  Double, Optional Info As  Long  ) Derivative of normalized incomplete gamma function P(a, x) (Subroutine version) Purpose Computes the derivative of normalized incomplete gamma function P(a, x) with respect to x. d/dx P(a, x) = exp(-x)*x^(a-1)/Γ(a) Parameters [out] Ret Derivative of normalized incomplete gamma function P(a, x) with respect to x. [in] A Argument a. (A > 0) [in] X Argument x. (X >= 0) [out] Info = 0: Successful exit. = -1: The argument A had an illegal value. (A <= 0) = -2: The argument X had an illegal value. (X < 0) = 1: Floating point range error. Reference boost/math/special_functions