Making some minor contributions to GSL

Gerard Jungman
Fri Jan 16 00:57:00 GMT 2004

On Tue, 2004-01-13 at 17:57, wrote:

> The only "deficiency" is that the GSL implementation generates
> a "domain error" when gsl_sf_psi_n (1,x) is called with 
> negative x.  The psi's should be perfectly well defined 
> for negative, non-integer x's.  

It might take me a while to get around to that. I don't think
I ever found a good way, or at least not one that I understood.

> Another minor suggestion/comment: It would be nice to have 
> a function that returns Riemann zeta -1, which provides better
> accuracy for the intermediate/larger values values of the argument. 

Now in CVS. The new functions are

    gsl_sf_zetam1_e(double s, gsl_sf_result * r);
    gsl_sf_zetam1_int_e(int n, gsl_sf_result * r);

along with the corresponding non-error-reporting versions.

This was a good suggestion. I missed
it the first time around.


Gerard Jungman <>
Los Alamos National Laboratory

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