BesselI Method (Double, Double, Int32) |
Evaluates a sequence of modified Bessel functions of the first kind
with real order and real argument.
Namespace: Imsl.MathAssembly: ImslCS (in ImslCS.dll) Version: 6.5.2.0
Syntax public static double[] I(
double xnu,
double x,
int n
)
Public Shared Function I (
xnu As Double,
x As Double,
n As Integer
) As Double()
public:
static array<double>^ I(
double xnu,
double x,
int n
)
static member I :
xnu : float *
x : float *
n : int -> float[]
Parameters
- xnu
- Type: SystemDouble
A double representing the lowest order desired. xnu
must be at least zero and less than 1.
- x
- Type: SystemDouble
A double representing the argument of the Bessel functions to
be evaluated.
- n
- Type: SystemInt32
The int order of the last element in the sequence.
Return Value
Type:
Double
A
double array of length
n + 1 containing the values of
the function through the series.
Remarks
Bessel.I[i] contains the value of the Bessel function of order i+xnu.
The Bessel function
, is defined to be
Here, argument xnu is represented by
in the above equation.
The input x must be nonnegative and less than or equal to
log(b) (b is the largest representable number). The argument
= xnu must satisfy .
This function is based on a code due to Cody (1983), which uses
backward recursion.
See Also