Bessel_j0
Definition:
, evaluates the Bessel function of the first kind,
. The approximation is based on Chebyshev expansions.
For more information please review the s17aec function in the NAG document.
Parameters:
- x (input, double)
- The argument x of the function.
- j0 (output, double)
- The approximation of the Bessel function.