public static double s18cc(
	double x,
	out int ifail
)

Public Shared Function s18cc ( _
	x As Double, _
	<OutAttribute> ByRef ifail As Integer _
) As Double

public:
static double s18cc(
	double x, 
	[OutAttribute] int% ifail
)

static member s18cc : 
        x : float * 
        ifail : int byref -> float 

s18cc returns a value of the scaled modified Bessel function $e^x{K}_0\left(x\right)$.

s18cc evaluates an approximation to $e^x{K}_0\left(x\right)$, where $K_0$ is a modified Bessel function of the second kind. The scaling factor $e^x$ removes most of the variation in $K_0\left(x\right)$.

The method uses the same Chebyshev expansions as s18ac, which returns the unscaled value of $K_0\left(x\right)$.

Abramowitz M and Stegun I A (1972) Handbook of Mathematical Functions (3rd Edition) Dover Publications

Errors or warnings detected by the method:

Relative errors in the argument are attenuated when propagated into the function value. When the accuracy of the argument is essentially limited by the machine precision, the accuracy of the function value will be similarly limited by at most a small multiple of the machine precision.

None.

None.

This example reads values of the argument $x$ from a file, evaluates the function at each value of $x$ and prints the results.