Re: [Bug-gsl] A small question about complex returns for hyperg_U()

[Brian Gough]

At Mon, 25 Oct 2010 19:52:44 -0500,
Raymond Rogers wrote:
> Inside of hyperg_U(a,b,x), x<0 is implemented.  In the code it's
> mentioned,correctly, that x<0, b<1 leads to complex solutions.
> Although the calculation is carried out (x^1-b, say (-1)^.5) there
> doesn't seem to be any provision for returning the complex value.
> Am I missing something?

If we're talking about hyperg_U_negx(a,b,x,&result) there is indeed no
provision for complex numbers, it is just going to return NaN if the
result is not real. 

I have to say I didn't implement all the possible cases that give real
results either, as mentioned in the comments there, only the most
obvious ones. 

-- 
Brian Gough