erf, erff, erfl, - error function
#include <math.h> double erf(double x); float erff(float x); long double erfl(long double x);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
_ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE || /* Since glibc 2.19: */ _DEFAULT_SOURCE || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
_ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L || /* Since glibc 2.19: */ _DEFAULT_SOURCE || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
These functions return the error function of
x, defined as
On success, these functions return the error function of
x, a value in the range [-1, 1].
x is a NaN, a NaN is returned.
x is +0 (-0), +0 (-0) is returned.
x is positive infinity (negative infinity), +1 (-1) is returned.
x is subnormal, a range error occurs, and the return value is 2*x/sqrt(pi).
See math_error(7) for information on how to determine whether an error has occurred when calling these functions.
The following errors can occur:
An underflow floating-point exception (FE_UNDERFLOW) is raised.
These functions do not set
C99, POSIX.1-2001, POSIX.1-2008.
The variant returning
double also conforms to SVr4, 4.3BSD.
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