************80
! CGAMA computes the Gamma function for complex argument.
Discussion:
This procedcure computes the gamma function Γ(z) or ln[Γ(z)]
for a complex argument
Licensing:
This routine is copyrighted by Shanjie Zhang and Jianming Jin. However,
they give permission to incorporate this routine into a user program
provided that the copyright is acknowledged.
Modified:
26 July 2012
Author:
Shanjie Zhang, Jianming Jin
Reference:
Shanjie Zhang, Jianming Jin,
Computation of Special Functions,
Wiley, 1996,
ISBN: 0-471-11963-6,
LC: QA351.C45.
Parameters:
Input, real ( kind = 8 ) X, Y, the real and imaginary parts of
the argument Z.
Input, integer ( kind = 4 ) KF, the function code.
0 for ln[Γ(z)]
1 for Γ(z)
Output, real ( kind = 8 ) GR, GI, the real and imaginary parts of
the selected function.
| Type | Intent | Optional | Attributes | Name | ||
|---|---|---|---|---|---|---|
| real(kind=8) | :: | x | ||||
| real(kind=8) | :: | y | ||||
| integer(kind=4) | :: | kf | ||||
| real(kind=8) | :: | gr | ||||
| real(kind=8) | :: | gi |