Dear all,

I'm looking for a routine which calculates the Gamma Function

for a complex valued variable. I'm using

#include <complex>

to work with complex numbers.

I define a complex number as

complex <doublealpha(3.0, 1.0)

So here alpha is a complex number with real part of alpha = 3.0

and imaginary part of alpha = 1.0.

By now, I've found "gammln" from Numerical Recipes. But

"gammln" is only working for double, i.e. real valued variables.

Typing

complex <doubletau(3.0,1.0);

cout<<"Gamma(3,1) "<<gammln(tau)<<endl;

gives

GammaComplexTest.cpp: In function `int main()':

GammaComplexTest.cpp:89: error: cannot convert `std::complex<double>'

to `

double' for argument `1' to `DP NR::gammln(double)'

It would be much appreciated if someone could tell me

where to find a routine which also allows to use complex valued

variables for the Gamma Function.

Many thanks!

Tina