2018-03-02 7:31 GMT-07:00 Piotr Caban piotr.caban@gmail.com:
This approximation can only be used for values in specific range to give reasonable results. There are similar problems with j0, j1 fallbacks (I haven't checked other functions).
I think it's better to print FIXME instead of adding very inaccurate fallback. Taking in account the functions are probably mainly used for physics related computations I guess it's better to avoid inaccurate implementation at all.
That's fair for jn, y0, y1, and yn. However, the j0 and j1 fallbacks are exactly correct, as far as I can tell. What values of x did you test? Did you accidentally have your calculator set to use degrees instead of radians?
-Alex