3.5.1.3.9 Bessel_i1

Bessel-i1-func

Definition:

evaluates an approximation to the modified Bessel function of the first kind,.The function is based on Chebyshev expansions.

For more information please review the s17afc function in the NAG document.

Parameters:

x (input, double)

The argument x of the function.

i1 (output, double)

Approximation of to the modified Bessel function of the first kind.