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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-24 04:52:22 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-24 04:52:22 +0000 |
commit | 3d08cd331c1adcf0d917392f7e527b3f00511748 (patch) | |
tree | 312f0d1e1632f48862f044b8bb87e602dcffb5f9 /man/man3/erf.3 | |
parent | Adding debian version 6.7-2. (diff) | |
download | manpages-3d08cd331c1adcf0d917392f7e527b3f00511748.tar.xz manpages-3d08cd331c1adcf0d917392f7e527b3f00511748.zip |
Merging upstream version 6.8.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'man/man3/erf.3')
-rw-r--r-- | man/man3/erf.3 | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/man/man3/erf.3 b/man/man3/erf.3 new file mode 100644 index 0000000..3cdfb0a --- /dev/null +++ b/man/man3/erf.3 @@ -0,0 +1,131 @@ +'\" t +.\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk) +.\" and Copyright 2008, Linux Foundation, written by Michael Kerrisk +.\" <mtk.manpages@gmail.com> +.\" +.\" SPDX-License-Identifier: Linux-man-pages-copyleft +.\" +.\" References consulted: +.\" Linux libc source code +.\" Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991) +.\" 386BSD man pages +.\" Modified 1993-07-24 by Rik Faith (faith@cs.unc.edu) +.\" Modified 2002-07-27 by Walter Harms +.\" (walter.harms@informatik.uni-oldenburg.de) +.\" +.TH erf 3 2024-05-02 "Linux man-pages (unreleased)" +.SH NAME +erf, erff, erfl \- error function +.SH LIBRARY +Math library +.RI ( libm ", " \-lm ) +.SH SYNOPSIS +.nf +.B #include <math.h> +.P +.BI "double erf(double " x ); +.BI "float erff(float " x ); +.BI "long double erfl(long double " x ); +.P +.fi +.RS -4 +Feature Test Macro Requirements for glibc (see +.BR feature_test_macros (7)): +.RE +.P +.BR erf (): +.nf + _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE + || /* Since glibc 2.19: */ _DEFAULT_SOURCE + || /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE +.fi +.P +.BR erff (), +.BR erfl (): +.nf + _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L + || /* Since glibc 2.19: */ _DEFAULT_SOURCE + || /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE +.fi +.SH DESCRIPTION +These functions return the error function of +.IR x , +defined as +.P +.in +4n +.EX +erf(x) = 2/sqrt(pi) * integral from 0 to x of exp(\-t*t) dt +.EE +.in +.SH RETURN VALUE +On success, these functions return the value of the error function of +.IR x , +a value in the range [\-1,\ 1]. +.P +If +.I x +is a NaN, a NaN is returned. +.P +If +.I x +is +0 (\-0), +0 (\-0) is returned. +.P +If +.I x +is positive infinity (negative infinity), ++1 (\-1) is returned. +.P +If +.I x +is subnormal, +a range error occurs, +and the return value is 2*x/sqrt(pi). +.SH ERRORS +See +.BR math_error (7) +for information on how to determine whether an error has occurred +when calling these functions. +.P +The following errors can occur: +.TP +Range error: result underflow (\fIx\fP is subnormal) +.\" .I errno +.\" is set to +.\" .BR ERANGE . +An underflow floating-point exception +.RB ( FE_UNDERFLOW ) +is raised. +.P +These functions do not set +.IR errno . +.\" It is intentional that these functions do not set errno for this case +.\" see https://www.sourceware.org/bugzilla/show_bug.cgi?id=6785 +.SH ATTRIBUTES +For an explanation of the terms used in this section, see +.BR attributes (7). +.TS +allbox; +lbx lb lb +l l l. +Interface Attribute Value +T{ +.na +.nh +.BR erf (), +.BR erff (), +.BR erfl () +T} Thread safety MT-Safe +.TE +.SH STANDARDS +C11, POSIX.1-2008. +.SH HISTORY +C99, POSIX.1-2001. +.P +The variant returning +.I double +also conforms to +SVr4, 4.3BSD. +.SH SEE ALSO +.BR cerf (3), +.BR erfc (3), +.BR exp (3) |