Bessel functions?

iamfromspacebaby's icon

I'm trying to find out how to implement a Bessel function. I've searched the forums and found that there is a function in JMSL, however, I cant afford it atm... does anyone know a free alternative? The equation in question is below:

Jn(K r) (C1 cos(n theta) + C2 sin(n theta))

All the best, Carl.

José Manuel Berenguer's icon
iamfromspacebaby's icon

Thanks man, as I'm not a mathematician can you explain how the Bessel function is implemented in the patch?

Hans Bernardd's icon

Nice approximation:

https://www.cl.cam.ac.uk/~jrh13/papers/bessel.pdf

newtfish's icon

I wonder where the crucial comment with the example patch in this thread has gone?