c99 [ flag... ] file... – lm [ library... ] #include <math.h> double erf(double x);
float erff(float x);
long double erfl(long double x);
These functions compute the error function of their argument x, defined as:
Upon successful completion, these functions return the value of the error function.
If x is NaN, a NaN is returned.
If x is ±0, ±0 is returned.
If x is ±Inf, ±1 is returned.
If x is subnormal, 2/sqrt(??) * 2 is returned.
See attributes(5) for descriptions of the following attributes: