diff options
Diffstat (limited to 'lib/msun/man/erf.3')
-rw-r--r-- | lib/msun/man/erf.3 | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/lib/msun/man/erf.3 b/lib/msun/man/erf.3 new file mode 100644 index 0000000..46886b0 --- /dev/null +++ b/lib/msun/man/erf.3 @@ -0,0 +1,93 @@ +.\" Copyright (c) 1985, 1991 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. +.\" 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. +.\" +.\" from: @(#)erf.3 6.4 (Berkeley) 4/20/91 +.\" $FreeBSD$ +.\" +.Dd April 20, 1991 +.Dt ERF 3 +.Os +.Sh NAME +.Nm erf , +.Nm erff , +.Nm erfc , +.Nm erfcf +.Nd error function operators +.Sh LIBRARY +.Lb libm +.Sh SYNOPSIS +.In math.h +.Ft double +.Fn erf "double x" +.Ft float +.Fn erff "float x" +.Ft double +.Fn erfc "double x" +.Ft float +.Fn erfcf "float x" +.Sh DESCRIPTION +These functions calculate the error function of +.Fa x . +.Pp +The +.Fn erf +and the +.Fn erff +functions calculate 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 +and the +.Fn erfcf +functions calculate 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 . |