Re: [Bug-gsl] hyperg_U(a,b,x) Questions about x<0 and values of a

[Brian Gough]

At Wed, 07 Jul 2010 10:14:34 -0500,
Raymond Rogers wrote:
> 
> 1) I was unable to find the valid domain of  the argument a when x<0. 
> Experimenting yields what seem to be erratic results.  Apparently
> correct answers occur when {x<0&a<0& a  integer}.  References would be
> sufficient.   Unfortunately {x<0,a<0} is exactly the wrong range for my
> problem; but the recursion relations can be used to stretch to a>0.  If
> I can find a range of correct operation for the domain of "a" of width >1.

Thanks for the email.  There are some comments about the domain for
the hyperg_U_negx function in specfunc/hyperg_U.c -- do they help?

-- 
Brian Gough