IBESSEL Function

Returns the value of the modified Bessel function.

Category: Mathematical

Syntax

IBESSEL(nu,x,kode)

Required Arguments

nu

specifies a numeric constant, variable, or expression.

Range nu ≥ 0

x

specifies a numeric constant, variable, or expression.

Range x ≥ 0

kode

is a numeric constant, variable, or expression that specifies a nonnegative integer.

Details

The IBESSEL function returns the value of the modified Bessel function of order nu evaluated at x (Abramowitz, Stegun 1964; Amos, Daniel, Weston 1977). When kode equals 0, the Bessel function is returned. Otherwise, the value of the following function is returned:
ε - x I n m ( x )

Example

The following SAS statements produce these results.
SAS Statement
Result
x=ibessel(2,2,0);
0.6889484477
x=ibessel(2,2,1);
0.0932390333