Evaluates the real error function erf(x).
Synopsis
#include <imsl.h>
float imsl_f_erf (float x)
The type double procedure is imsl_d_erf.
Required Arguments
float x
(Input)
Point at which the error function is to be evaluated.
Return Value
The value of the error function erf(x).
Description
The error function erf(x) is defined to be
All values of x are legal.
Figure 9- 1 Plot of erf(x)
Example
Evaluate the error function at x = 1∕2.
#include <imsl.h>
int main()
{
float x = 0.5;
float ans;
ans = imsl_f_erf(x);
printf("erf(%f) = %f\n", x, ans);
}
Output
erf(0.500000) = 0.520500
