46eea498da
to be the same as -ragged in the current implementation) to -ragged. With mdocNG, -filled displays produce the correct output, formatted and justified to both margins.
86 lines
2.7 KiB
Groff
86 lines
2.7 KiB
Groff
.\" Copyright (c) 1985, 1991, 1993
|
|
.\" The Regents of the University of California. All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\" 3. All advertising materials mentioning features or use of this software
|
|
.\" must display the following acknowledgement:
|
|
.\" This product includes software developed by the University of
|
|
.\" California, Berkeley and its contributors.
|
|
.\" 4. Neither the name of the University nor the names of its contributors
|
|
.\" may be used to endorse or promote products derived from this software
|
|
.\" without specific prior written permission.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.\" @(#)erf.3 8.1 (Berkeley) 6/4/93
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd June 4, 1993
|
|
.Dt ERF 3
|
|
.Os BSD 4.3
|
|
.Sh NAME
|
|
.Nm erf ,
|
|
.Nm erfc
|
|
.Nd error function operators
|
|
.Sh LIBRARY
|
|
.Lb libm
|
|
.Sh SYNOPSIS
|
|
.Fd #include <math.h>
|
|
.Ft double
|
|
.Fn erf "double x"
|
|
.Ft double
|
|
.Fn erfc "double x"
|
|
.Sh DESCRIPTION
|
|
These functions calculate the error function of
|
|
.Fa x .
|
|
.Pp
|
|
The
|
|
.Fn erf
|
|
calculates the error function of x; where
|
|
.Bd -ragged -offset indent
|
|
.if n \{\
|
|
erf(x) = 2/sqrt(pi)\(**\|integral from 0 to x of exp(\-t\(**t) dt. \}
|
|
.if t \{\
|
|
erf\|(x) :=
|
|
(2/\(sr\(*p)\|\(is\d\s8\z0\s10\u\u\s8x\s10\d\|exp(\-t\u\s82\s10\d)\|dt. \}
|
|
.Ed
|
|
.Pp
|
|
The
|
|
.Fn erfc
|
|
function calculates the complementary error function of
|
|
.Fa x ;
|
|
that is
|
|
.Fn erfc
|
|
subtracts the result of the error function
|
|
.Fn erf x
|
|
from 1.0.
|
|
This is useful, since for large
|
|
.Fa x
|
|
places disappear.
|
|
.Sh SEE ALSO
|
|
.Xr math 3
|
|
.Sh HISTORY
|
|
The
|
|
.Fn erf
|
|
and
|
|
.Fn erfc
|
|
functions appeared in
|
|
.Bx 4.3 .
|