Manual pages › Math library (3M)

erf(3M)

error function and complementary error function

From the original Amiga UNIX 2.1 manual. Some things it mentions may not be in this release.

NAME

erf, erfc - error function and complementary error function

SYNOPSIS

cc [flag ...] file ...  -lm [library ...]

#include <math.h>

double erf (double x);

double erfc (double x);

DESCRIPTION

erf retuxns the error function of x, defined as
      2     2
     ___^e-t dt
     \/J
        0
erfc, which returns 1.0 - erf(x), is provided because of the
extreme  loss  of  relative accuracy if erf(x) is called for
large x and the result subtracted from 1.0 (e.g., for x = 5,
12 places are lost).

SEE ALSO

exp(3M).