MirBSD manpage: gamma(3), gammaf(3), gammaf_r(3), gamma_r(3), lgamma(3), lgammaf(3), lgammaf_r(3), lgamma_r(3)

LGAMMA(3)                  BSD Programmer's Manual                   LGAMMA(3)

NAME

lgamma, lgammaf, lgamma_r, lgammaf_r, gamma, gammaf, gamma_r, gammaf_r -
log gamma function

libm

SYNOPSIS

#include <math.h>

extern int signgam;

double
lgamma(double x);

float
lgammaf(float x);

double
lgamma_r(double x, int *sign);

float
lgammaf_r(float x, int *sign);

double
gamma(double x);

float
gammaf(float x);

double
gamma_r(double x, int *sign);

float
gammaf_r(float x, int *sign);

DESCRIPTION

lgamma(x) returns ln|I̅(x)|.

The external integer signgam returns the sign of I̅(x).

lgamma_r() is a reentrant interface that performs identically to lgam-
ma(), differing in that the sign of I̅(x) is stored in the location point-
ed to by the sign argument and signgam is not modified.

IDIOSYNCRASIES

Do not use the expression "signgam*exp(lgamma(x))" to compute g := I̅(x).
Instead use a program like this (in C):

lg = lgamma(x); g = signgam*exp(lg);

Only after lgamma() has returned can signgam be correct.

RETURN VALUES

lgamma() returns appropriate values unless an argument is out of range.
Overflow will occur for sufficiently large positive values, and non-
positive integers. On the VAX, the reserved operator is returned, and
errno is set to ERANGE.

math(3)

HISTORY

The lgamma function appeared in 4.3BSD.

MirBSD #10-current             December 3, 1992                              1

Generated on 2022-12-24 01:00:14 by \$MirOS: src/scripts/roff2htm,v 1.113 2022/12/21 23:14:31 tg Exp \$ — This product includes material provided by mirabilos.

These manual pages and other documentation are copyrighted by their respective writers; their sources are available at the project’s CVSweb, AnonCVS and other mirrors. The rest is Copyright © 2002–2022 MirBSD.

This manual page’s HTML representation is supposed to be valid XHTML/1.1; if not, please send a bug report — diffs preferred.

Kontakt / Impressum & Datenschutzerklärung