Evaluates a sequence of Bessel functions of the first kind with integer order and real argument.

Namespace: Imsl.Math
Assembly: ImslCS (in ImslCS.dll) Version: 6.5.0.0

Syntax

C#
public static double[] J(
	double x,
	int n
)
Visual Basic (Declaration)
Public Shared Function J ( _
	x As Double, _
	n As Integer _
) As Double()
Visual C++
public:
static array<double>^ J(
	double x, 
	int n
)

Parameters

x
Type: System..::.Double
A double representing the argument for which the sequence of Bessel functions is to be evaluated.
n
Type: System..::.Int32
A int which specifies the order of the last element in the sequence.

Return Value

A double array of length n + 1 containing the values of the function through the series.

Remarks

Bessel.J[i] contains the value of the Bessel function of order i at x for i = 0 to n.

The Bessel function J_n (x), is defined to be

J_n \left( x \right) = {1 \over \pi }\int_0^\pi {\,\cos \left( {x\,\sin \,\theta - n\,\theta } \right)\,} d\,\theta

The algorithm is based on a code due to Sookne (1973b) that uses backward recursion with strict error control.

See Also