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.\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk)
.\" and Copyright 2008, Linux Foundation, written by Michael Kerrisk
.\" <mtk.manpages@gmail.com>
.\"
.\" Permission is granted to make and distribute verbatim copies of this
.\" manual provided the copyright notice and this permission notice are
.\" preserved on all copies.
.\"
.\" Permission is granted to copy and distribute modified versions of this
.\" manual under the conditions for verbatim copying, provided that the
.\" entire resulting derived work is distributed under the terms of a
.\" permission notice identical to this one.
.\"
.\" Since the Linux kernel and libraries are constantly changing, this
.\" manual page may be incorrect or out-of-date. The author(s) assume no
.\" responsibility for errors or omissions, or for damages resulting from
.\" the use of the information contained herein. The author(s) may not
.\" have taken the same level of care in the production of this manual,
.\" which is licensed free of charge, as they might when working
.\" professionally.
.\"
.\" Formatted or processed versions of this manual, if unaccompanied by
.\" the source, must acknowledge the copyright and authors of this work.
.\"
.\" 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)
.\"
.\" Japanese Version Copyright (c) 1997 YOSHINO Takashi
.\" all rights reserved.
.\" Translated Mon Jan 20 20:17:40 JST 1997
.\" by YOSHINO Takashi <yoshino@civil.jcn.nihon-u.ac.jp>
.\" Updated Tue Aug 5 23:16:48 JST 2003
.\" by Akihiro MOTOKI <amotoki@dd.iij4u.or.jp>
.\" Updated & Modified Tue Feb 15 04:46:24 JST 2005
.\" by Yuichi SATO <ysato444@yahoo.co.jp>
.\"
.\"WORD: complementary error function ؿ
.\"WORD: subnormal
.\"
.TH ERF 3 2008-08-05 "GNU" "Linux Programmer's Manual"
.SH ̾
erf, erff, erfl \- ؿ
.SH
.nf
.B #include <math.h>
.BI "double erf(double " x );
.BI "float erff(float " x );
.BI "long double erfl(long double " x );
.fi
\fI\-lm\fP ǥ롣
.sp
.in -4n
glibc εǽޥ
.RB ( feature_test_macros (7)
):
.in
.sp
.ad l
.BR erf ():
_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE || _ISOC99_SOURCE; or
.I cc\ -std=c99
.br
.BR erff (),
.BR erfl ():
_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE\ >=\ 600|| _ISOC99_SOURCE; or
.I cc\ -std=c99
.ad b
.SH
.BR erf ()
\fIx\fP θؿ֤ؿǡʲΤ褦Ƥ롣
.TP
erf(x) = 2/sqrt(pi)* integral from 0 to x of exp(\-t*t) dt
.SH ֤
ȡδؿ
.I x
θؿ֤
֤ͤ [\-1,\ 1] ϰϤȤʤ롣
.I x
NaN ξ硢NaN ֤롣
.I x
+0 (\-0) ξ硢+0 (\-0) ֤롣
.I x
̵ (̵) ξ硢+1 (\-1) ֤롣
.I x
ξ硢ϰϥ顼 (range error) ȯ
֤ͤ 2*x/sqrt(pi) Ȥʤ롣
.SH 顼
δؿƤӽФݤ˥顼ȯȽˡˤĤƤξ
.BR math_error (7)
ȤΤȡ
.PP
ʲΥ顼ȯǽ롣
.TP
ϰϥ顼 (range error): ̤ե (\fIx\fP )
.\" .I errno
.\" is set to
.\" .BR ERANGE .
եư㳰
.RB ( FE_UNDERFLOW )
夬롣
.PP
δؿ
.I errno
ꤷʤ
.\" FIXME . Is it intentional that these functions do not set errno?
.\" Bug raised: http://sources.redhat.com/bugzilla/show_bug.cgi?id=6785
.SH
C99, POSIX.1-2001.
.I double
Ǥδؿ SVr4, 4.3BSD ˤƤ롣
.SH Ϣ
.BR cerf (3),
.BR erfc (3),
.BR exp (3)
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