Hello, everyone. I am new and hoping to make my first contribution. I read through the Wish List, and I thought I could help quickly by starting with the special functions request.
I created a JIRA (https://issues.apache.org/jira/browse/MATH-1066) that contains a patch for Bessel functions of the first kind. There are other Bessel functions that are relevant, but I figured I would post that, to get (minor, hopefully) suggestions or tweaks to get it ready, to streamline the process for other functions. The JIRA is a bit sparse, so some more details on the patch follow. Like several other open source packages, I started from Fortran code in Netlib; in this case, http://www.netlib.org/specfun/rjbesl . As a first pass, I enabled the double-precision lines with IEEE values already in the code and then put the Fortran code through f2j ( http://www.netlib.org/java/f2j/). This handled the straightforward parts, but it left in gotos and some other bits that needed cleaning. Getting the output of f2j to a decent place took more time and effort than I had anticipated, but it is passing the unit tests I put in (based on output from R, which uses a translation of the same Fortran code). I am looking forward to hearing thoughts and suggestions. Kind regards, Brian
