Computes the exponential integral.

Namespace:  Meta.Numerics.Functions
Assembly:  Meta.Numerics (in Meta.Numerics.dll) Version: 1.4.0.0 (1.4.0.0)

Syntax

         
 C#  Visual Basic  Visual C++ 
public static double IntegralE(
	int n,
	double x
)
Public Shared Function IntegralE ( _
	n As Integer, _
	x As Double _
) As Double
public:
static double IntegralE(
	int n, 
	double x
)

Parameters

n
Int32
The order parameter, which must be non-negative.
x
Double
The argument, which must be non-negative.

Return Value

The value of Ein(x).

Remarks

The exponential integral is defined as Ein(x) = 1∫∞dt e-xt/tn.

It is related to the incomplete Gamma function for negative, integer shape parameters by ΓQ(-k, x) = Eik+1(x) / xk.

Exceptions

See Also