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IEEE 802.11 is part of the IEEE 802 set of LAN protocols, and specifies the set of media access control (MAC) and physical layer (PHY) protocols for implementing virtual local area network (VLAN) Wi-Fi computer communication in various frequencies.
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erf(3) [linux man page]

ERF(3)							     Linux Programmer's Manual							    ERF(3)

NAME
erf, erff, erfl, - error function SYNOPSIS
#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)): erf(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE || _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L; or cc -std=c99 erff(), erfl(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L; or cc -std=c99 DESCRIPTION
The 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 VALUE
On 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. If x is subnormal, a range error occurs, and the return value is 2*x/sqrt(pi). 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 (x is subnormal) An underflow floating-point exception (FE_UNDERFLOW) is raised. These functions do not set errno. CONFORMING TO
C99, POSIX.1-2001. The variant returning double also conforms to SVr4, 4.3BSD. SEE ALSO
cerf(3), erfc(3), exp(3) COLOPHON
This page is part of release 3.27 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/. GNU
2010-09-20 ERF(3)

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ERFC(3) 						     Linux Programmer's Manual							   ERFC(3)

NAME
erfc, erfcf, erfcl - complementary error function SYNOPSIS
#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)): erfc(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE || _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L; or cc -std=c99 erfcf(), erfcl(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600|| _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L; or cc -std=c99 DESCRIPTION
The erfc() function returns 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. CONFORMING TO
C99, POSIX.1-2001. The variant returning double also conforms to SVr4, 4.3BSD. NOTES
The 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 ALSO
cerf(3), erf(3), exp(3) COLOPHON
This page is part of release 3.27 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/. GNU
2010-09-20 ERFC(3)

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