# Bessel_i_nu_scaled

Bessel-i-nu-scaled-func

## Definition:

evaluates an approximation to the modified Bessel function of the first kind , where the order =-3, -2, -1, 1, 2 or 3 and x is real and positive. For positive orders it may also be called with x=0, since when > 0. For negative orders the formula

is used prior to multiplication by the scale factor .

For more information please review the s18ecc function in the NAG document.

## Parameters:

- x (input, double)
- The argument x of the function.
- Constraints:

x>0.0 when nu<0,
x???0.0 when nu>0.

- (input, int)
- The argument of the function.
- Constraints:

- (output, double)
- Approximation of the modified Bessel function of the first kind.