From mboxrd@z Thu Jan  1 00:00:00 1970
To: 9fans@cse.psu.edu
Date: Fri, 16 Nov 2007 10:19:28 +0000
From: "Douglas A. Gwyn" <DAGwyn@null.net>
Message-ID: <473CA7E7.42F1A40F@null.net>
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References: <8FE905C8-9071-4DF4-B4E2-76A3991C4D0B@mac.com>,
	<7b5cf09fd7ee547030c620733fb4cee1@terzarima.net>
Subject: Re: [9fans] Problems with pcc
Topicbox-Message-UUID: fceafd1c-ead2-11e9-9d60-3106f5b1d025

Charles Forsyth wrote:
> ape doesn't provide gamma or cbrt, but if they're in c99 i suppose it could.
> just add a local copy temporarily.
> gamma isn't in my copy of c99 though: it defines lgamma and tgamma.
> (the old gamma actually computed lgamma, i think.)

Yes, the name "gamma" had been used for both the gamma function
and its logarithm, on different platforms, so the C standard uses
other names for each of them.  My version looks like:

/* hoc/math.c */
#include <math.h>
#if defined(__STDC__) && !defined(gamma)
#define	gamma(x)	lgamma(x)	/* new name */
#endif
extern int signgam;
...
double
Gamma(x)
	double x;
{
	double y;
	y = errcheck((double)gamma(x), "gamma");
#if 0	/* DAG -- not needed with following check on exp(y) */
	if (y > 88.0)
		execerror("gamma result out of range", (char *)0);
#endif
	y = errcheck((double)exp(y), "gamma");	/* DAG -- added check */
	return signgam * y;
}
...