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diff --git a/lib/msun/man/lgamma.3 b/lib/msun/man/lgamma.3 new file mode 100644 index 0000000..ea6eb6f --- /dev/null +++ b/lib/msun/man/lgamma.3 @@ -0,0 +1,189 @@ +.\" 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: @(#)lgamma.3 6.6 (Berkeley) 12/3/92 +.\" $FreeBSD$ +.\" +.Dd January 14, 2005 +.Dt LGAMMA 3 +.Os +.Sh NAME +.Nm lgamma , +.Nm lgamma_r , +.Nm lgammaf , +.Nm lgammaf_r , +.Nm gamma , +.Nm gamma_r , +.Nm gammaf , +.Nm gammaf_r , +.Nm tgamma , +.Nm tgammaf +.Nd log gamma functions, gamma function +.Sh LIBRARY +.Lb libm +.Sh SYNOPSIS +.In math.h +.Ft extern int +.Fa signgam ; +.sp +.Ft double +.Fn lgamma "double x" +.Ft double +.Fn lgamma_r "double x" "int *signgamp" +.Ft float +.Fn lgammaf "float x" +.Ft float +.Fn lgammaf_r "float x" "int *signgamp" +.Ft double +.Fn gamma "double x" +.Ft double +.Fn gamma_r "double x" "int *signgamp" +.Ft float +.Fn gammaf "float x" +.Ft float +.Fn gammaf_r "float x" "int *signgamp" +.Ft double +.Fn tgamma "double x" +.Ft float +.Fn tgammaf "float x" +.Sh DESCRIPTION +.Fn lgamma x +and +.Fn lgammaf x +.if t \{\ +return ln\||\(*G(x)| where +.Bd -unfilled -offset indent +\(*G(x) = \(is\d\s8\z0\s10\u\u\s8\(if\s10\d t\u\s8x\-1\s10\d e\u\s8\-t\s10\d dt for x > 0 and +\(*G(x) = \(*p/(\(*G(1\-x)\|sin(\(*px)) for x < 1. +.Ed +.\} +.if n \ +return ln\||\(*G(x)|. +The external integer +.Fa signgam +returns the sign of \(*G(x). +.Pp +.Fn lgamma_r x signgamp +and +.Fn lgammaf_r x signgamp +provide the same functionality as +.Fn lgamma x +and +.Fn lgammaf x +but the caller must provide an integer to store the sign of \(*G(x). +.Pp +The +.Fn tgamma x +and +.Fn tgammaf x +functions return \(*G(x), with no effect on +.Fa signgam . +.Pp +.Fn gamma , +.Fn gammaf , +.Fn gamma_r , +and +.Fn gammaf_r +are deprecated aliases for +.Fn lgamma , +.Fn lgammaf , +.Fn lgamma_r , +and +.Fn lgammaf_r , +respectively. +.Sh IDIOSYNCRASIES +Do not use the expression +.Dq Li signgam\(**exp(lgamma(x)) +to compute g := \(*G(x). +Instead use a program like this (in C): +.Bd -literal -offset indent +lg = lgamma(x); g = signgam\(**exp(lg); +.Ed +.Pp +Only after +.Fn lgamma +or +.Fn lgammaf +has returned can signgam be correct. +.Pp +For arguments in its range, +.Fn tgamma +is preferred, as for positive arguments +it is accurate to within one unit in the last place. +Exponentiation of +.Fn lgamma +will lose up to 10 significant bits. +.Sh RETURN VALUES +.Fn gamma , +.Fn gamma_r , +.Fn gammaf , +.Fn gammaf_r , +.Fn lgamma , +.Fn lgamma_r , +.Fn lgammaf , +and +.Fn lgammaf_r +return appropriate values unless an argument is out of range. +Overflow will occur for sufficiently large positive values, and +non-positive integers. +For large non-integer negative values, +.Fn tgamma +will underflow. +.Sh SEE ALSO +.Xr math 3 +.Sh STANDARDS +The +.Fn lgamma , +.Fn lgammaf , +.Fn tgamma , +and +.Fn tgammaf +functions are expected to conform to +.St -isoC-99 . +.Sh HISTORY +The +.Fn lgamma +function appeared in +.Bx 4.3 . +The +.Fn gamma +function appeared in +.Bx 4.4 +as a function which computed \(*G(x). +This version was used in +.Fx 1.1 . +The name +.Fn gamma +was originally dedicated to the +.Fn lgamma +function, +and that usage was restored by switching to Sun's fdlibm in +.Fx 1.1.5 . +The +.Fn tgamma +function appeared in +.Fx 5.0 . |