Bessel Functions of the First Kind

[DavidB]

Hello.

I am looking for a routine for computing Bessel functions of the first kind, of order n:

J [sub]n[/sub] (x) = . . .

In my intended applications, both n and the argument of the function, x, will be real and positive. n is an integer.
I have done some searches and get MANY results, so I am not sure which routine is best.

What is the recommended routine in the NETLIB library for computing J sub n?

[Julien Langou]

There is no implementation of the Bessel functions in LAPACK.

[cottrell]

The cephes library does a good job on this sort of thing:
http://www.netlib.org/cephes/

Allin Cottrell

[DavidB]

Thanks, Allin.

I hadn't come across cephes before. It seems to have code for a good variety of problems, including elliptical integrals and functions (which was going to be one of my next posts). And the source code is in C, which I like.