Evaluates the real Bessel function of the first kind of order zero J0(x).
Synopsis
#include <imsl.h>
float imsl_f_bessel_J0 (float x)
The type double procedure is imsl_d_bessel_J0.
Required Arguments
float x
(Input)
Point at which the Bessel function is to be evaluated.
Return Value
The value of the Bessel function
If no solution can be computed, NaN is returned.
Description
Because the Bessel function J0(x) is oscillatory, its computation becomes inaccurate as |x| increases.
Figure 9- 9 Plot of J0 (x) and J1 (x)
Example
The Bessel function J0(1.5) is evaluated.
#include <imsl.h>
int main()
{
float x = 1.5;
float ans;
ans = imsl_f_bessel_J0(x);
printf("J0(%f) = %f\n", x, ans);
}
Output
J0(1.500000) = 0.511828
Warning Errors
IMSL_LARGE_ABS_ARG_WARN
|x| should be less than 
where ɛ is the machine
precision, to prevent the answer from being less accurate than half
precision.
Fatal Errors
IMSL_LARGE_ABS_ARG_FATAL |x| should be less than 1/ɛ where ɛ is the machine precision for the answer to have any precision.
