3.5.2.5.10 Bessel_i1_scaled

Definition:

i1\_scaled = bessel\_i1\_scaled(x) evaluates an approximation to e^{-|x|}I_1(x), where I_1(x) is a modified Bessel function of the first kind. The scanling factor e^{-|x|} removes most of the variation in I_1(x).

For more information please review the s18cfc function in the NAG document.


Parameters:

x (input, double)
The argument x of the function.
i1_scaled (output, double)
Approximation of e^{-|x|}I_1(x).