NAME
erf, erff,
erfl, erfc,
erfcf, erfcl —
error function operators
LIBRARY
library “libm”
SYNOPSIS
#include
<math.h>
double
erf(double
x);
float
erff(float
x);
long double
erfl(long
double x);
double
erfc(double
x);
float
erfcf(float
x);
long double
erfcl(long
double x);
DESCRIPTION
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.
SEE ALSO
HISTORY
The erf() and
erfc() functions appeared in
4.3BSD.