ERF(3) BSD Programmer's Manual ERF(3)
erf, erff, erfc, erfcf - error function operators
libm
#include <math.h> double erf(double x); float erff(float x); double erfc(double x); float erfcf(float x);
These functions calculate the error function of x. The erf() calculates the error function of x; where erf(x) = 2/sqrt(pi)*integral from 0 to x of exp(-t*t) dt. The erfc() function calculates the complementary error function of x; that is erfc() subtracts the result of the error function erf(x) from 1.0. This is useful, since for large x places disappear.
math(3)
The erf() and erfc() functions appeared in 4.3BSD. MirBSD #10-current April 20, 1991 1