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.