kelvin_kei0_derivative
Evaluates the derivative of the Kelvin function of the second kind, kei, of order zero.
Synopsis
#include <imsl.h>
float imsl_f_kelvin_kei0_derivative (float x)
The type double function is imsl_d_kelvin_kei0_derivative.
Required Arguments
float x (Input)
Argument for which the function value is desired.
Return Value
The derivative of the Kelvin function of the second kind, kei, of order zero evaluated at x.
Description
The function kei0′(x) is defined to be
The function imsl_f_kelvin_kei0_derivative is based on the work of Burgoyne (1963).
If x < 0, NaN (Not a Number) is returned. If x ≥ 119, zero is returned.
Example
In this example, kei0′(0.6) is evaluated.
#include <imsl.h>
#include <stdio.h>
int main()
{
float x = 0.6;
float ans;
x = imsl_f_kelvin_kei0_derivative (x);
printf ("kei0’(0.6) = %f\n", x);
}
Output
kei0’(0.6) = 0.348164