Manual Pages  — ERF

erf, erff, erfl, erfc, erfcf, erfcl – error function operators

LIBRARY SYNOPSIS DESCRIPTION SEE ALSO STANDARDS HISTORY

Math Library (libm, -lm)

#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);

These functions calculate the error function of x.

The erf(), erff(), and erfl() functions calculate the error function of x; where erf(x) = 2/sqrt(pi)*integral from 0 to x of exp(-t*t) dt. erf(x) := (2/√π)∫₀^xexp(-t²)dt.

The erfc(), erfcf(), and erfcl() functions calculate the complementary error function of x; that is erfc() subtracts the result of the error function erf(x) from 1.0.

The erf(), erff(), erfl(), erfc(), erfcf() and erfcl() functions conform to ISO/IEC 9899:1999 ("ISO C99").

The erf() and erfc() functions appeared in BSD 4.3 .