|ERFC(3)||Linux Programmer's Manual||ERFC(3)|
NAME¶erfc, erfcf, erfcl - complementary error function
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)):
DESCRIPTION¶These functions return the complementary error function of x, that is, 1.0 - erf(x).
RETURN VALUE¶On 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.
If the function result underflows but produces a representable (i.e., subnormal) value, that value is returned, and a range error occurs.
ERRORS¶See 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.
These functions do not set errno.
ATTRIBUTES¶For an explanation of the terms used in this section, see attributes(7).
|erfc (), erfcf (), erfcl ()||Thread safety||MT-Safe|
CONFORMING TO¶C99, POSIX.1-2001, POSIX.1-2008.
The variant returning double also conforms to SVr4, 4.3BSD.
NOTES¶The erfc(), erfcf(), and erfcl() 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 ALSO¶cerf(3), erf(3), exp(3)
COLOPHON¶This page is part of release 5.04 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.