Bessel_i1

Definition:

\(i1 = bessel\_i1(x)\) evaluates an approximation to the modified Bessel function of the first kind,\(I_1(x)\).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.