bessel_I0
Evaluates the real modified Bessel function of the first kind of order zero I0(x).
Synopsis
#include <imsl.h>
float imsl_f_bessel_I0 (float x)
The type double procedure is imsl_d_bessel_I0.
Required Arguments
float x (Input)
Point at which the modified Bessel function is to be evaluated.
Point at which the modified Bessel function is to be evaluated.
Return Value
The value of the Bessel function
If no solution can be computed, NaN is returned.
Description
For large ∣x∣, imsl_f_bessel_I0 will overflow.
Figure 18, Plot of I0(x) and I1(x)
Example
The Bessel function I0(1.5) is evaluated.
#include <imsl.h>
#include <stdio.h>
int main()
{
float x = 1.5;
float ans;
ans = imsl_f_bessel_I0(x);
printf("I0(%f) = %f\n", x, ans);
}
Output
I0(1.500000) = 1.646723
Fatal Errors
IMSL_LARGE_ABS_ARG_FATAL | The absolute value of x must not be so large that e|x| overflows. |
