I still remember back in 2004 when I needed to use the bessel j functions for a C++ electromagnetics simulation for the university. Back then, these functions w

I still remember back in 2004 when I needed to use the bessel j functions for a C++ electromagnetics simulation for the university. Back then, these functions were only available on a 1986 Fortran implementation by DE Amos (https://dl.acm.org/doi/10.1145/7921.214331 https://dl.acm.org/doi/10.1145/7921.214331). I was so delighted when I was able to compile the fortran sources as .obj files and then call them from my C++ program to receive the correct results!