[Help-gsl] ln gamma |x| too large error

[Clare Quarman]

Hi.

When using the special function lngamma_sgn_e, sometimes I receive an
error, the only info is that it's from line 1249 in gamma.c.  Looking at
this bit of gamma.c, a nearby comment states that |x| is too large for the 
fractional part to be extracted.

I'm not very familiar with methods for calculating lngamma functions and I
can't quite see from the rest of the lngamma_sgn_e code quite what values
of x would lead to this error.  There doesn't appear to be any reference
to a restriction on |x| in the manual.

I'm wondering if this restriction the same both for +ve and -ve values of
x, and what constitutes too large a magnitude for x?

Does anyone understand what's going on here?

Thanks,

Clare.