erf(3m) erf(3m)
Name
erf, erfc - error functions
Syntax
#include <math.h>
double erf(x)
double x;
double erfc(x)
double x;
Description
The function returns the error function of x defined as follows:
erf(x) = 2/sqrt(pi)*integral from 0 to x of exp(-t*t) dt.
The function returns 1.0-erf(x).
The entry for the function is provided because of the extreme loss of relative accuracy if erf(x) is called for large x and the result sub-
tracted from 1. For example if x = 10, 12 places are lost.
Return Values
The and functions return NaN when x is NaN.
See Also
math(3m)
RISC erf(3m)
