HP C/iX Library Reference Manual (30026-90004)

Chapter 5 137
HP C/iX Library Function Descriptions
erfc
erfc
Returns the complementary error function of the input value.
Syntax
#include <math.h>
double erfc (double x );
Parameters
x A real number defining the upper limit of the integral.
Return Values
n The complement of the integral given by the error function from 0 to x .
Description
The erfc function returns the complementary error function, 1- erf(x). This function is
provided because of the extreme loss of relative accuracy when erf(
x ) is called for large
values of
x . If erf(5) is called and the return value subtracted from 1, 12 places of
accuracy are lost when compared to calling erfc(5).
See Also
exp(), erf()