Manual Section... (3) - page: erfc
NAMEerfc, erfcf, erfcl - complementary error function
#include <math.h> double erfc(double x); float erfcf(float x); long double erfcl(long double x);Link with -lm.
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
DESCRIPTIONThe erfc() function returns the complementary error function of x, that is, 1.0 - erf(x).
RETURN VALUEOn success, these functions return the complementary error function of x, a value in the range [0,2].
If x is a NaN, a NaN is returned.
If x is +0 or -0, 1 is returned.
If x is positive infinity, +0 is returned.
If x is negative infinity, +2 is returned.
If the function result underflows and produces an unrepresentable value, the return value is 0.0.
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 (result 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.
NOTESThe erfc() functions are provided to avoid the loss accuracy that would occur for the calculation 1-erf(x) for large values of x (for which the value of erf(x) approaches 1).
SEE ALSOcerf(3), erf(3), exp(3)
COLOPHONThis page is part of release 3.24 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/.
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Time: 15:26:59 GMT, June 11, 2010