ERFSection: Linux Programmer's Manual (3)
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NAMEerf, erff, erfl, - error function
#include <math.h> double erf(double x); float erff(float x); long double erfl(long double x);Link with -lm.
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
DESCRIPTIONThe erf() function returns the error function of x, defined as
erf(x) = 2/sqrt(pi)* integral from 0 to x of exp(-t*t) dt
RETURN VALUEOn success, these functions return the error function of x, a value in the range [-1, 1].
If x is a NaN, a NaN is returned.
If x is +0 (-0), +0 (-0) is returned.
If x is positive infinity (negative infinity), +1 (-1) is returned.
ERRORSSee math_error(7) for information on how to determine whether an error has occurred when calling these functions.
The following errors can occur:
- Range error: result underflow (x is subnormal)
- An underflow floating-point exception (FE_UNDERFLOW) is raised.
CONFORMING TOC99, POSIX.1-2001. The variant returning double also conforms to SVr4, 4.3BSD.
SEE ALSOcerf(3), erfc(3), exp(3)
COLOPHONThis page is part of release 3.21 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.