[Help-gsl] Question about error margins on Bessel Functions

[joe bradley]

Hi everyone,

I'm new to the list.  I wanted to introduce myself and I have a question.
I'm a graduate student in physics and mathematics, and I've used the library
off and on for a couple years now.  First off, thanks to all the developers
out there--the library is great!

Ok, on to my question:  I'd like to know where I can find documentation on
how the error margins are computed for the Bessel functions.  (Specifically,
I'm working with the function gsl_sf_bessel_I0_e; one of the so-called
regular modified cylindrical bessel functions.)

I've looked a little at the code for the function, but everything is
computed using Chebyshev polynomials, which I don't know much about. Is
there any kind of documentation _between_ the standard documentation (which
doesn't seem to address this kind of question much) and the source code?

Thanks in advance,
Joe