Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!wuarchive!zaphod.mps.ohio-state.edu!unix.cis.pitt.edu!dsinc!ub!csn!boulder!spot.Colorado.EDU!hartkopf
From: hartkopf@spot.Colorado.EDU (Jeff Hartkopf)
Newsgroups: comp.sys.apple2
Subject: Problems with sinh function in ORCA/C
Keywords: math, ORCA/C, programming
Message-ID: <1991May21.032549.25803@colorado.edu>
Date: 21 May 91 03:25:49 GMT
Sender: news@colorado.edu (The Daily Planet)
Organization: University of Colorado, Boulder
Lines: 37
Nntp-Posting-Host: spot.colorado.edu



Does anyone know of any problems either with the ORCA/C 1.2 hyperbolic sine
(sinh) function itself, or with the SANE call(s) it makes?  I ask because 
I'm having a wierd problem with it.  If I boot the IIGS and run ORCA/C, and 
then run the following program, everything works fine:


#include <math.h>
#include <stdio.h>

extended mine(extended x)
/* my sinh function for testing purposes */
{
	return ((exp(x) - exp(-x))/2);  /* this is the formula for sinh(x) */
}

void main(void)
{
	printf("sinh(%f) = %f\n", 4.0, sinh(4.0));
	printf("mine(%f) = %f\n", 4.0, mine(4.0));
}


In other words, both printf statements print out the same thing (~27.289...), 
as they should.  However, after I run some other programs, do some
calculations, etc., and then run the above program again, the ORCA/C
sinh function doesn't return the right value, although my sinh function
*does* return the right value.  And the result of ORCA/C's sinh is off
by approximately a factor of 2, something like 54.xxx.

Anyone have any ideas?


Jeff Hartkopf
University of Colorado at Boulder
Internet: hartkopf@spot.colorado.edu