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From: j@uriah.heep.sax.de (J Wunsch)
Newsgroups: comp.unix.bsd.freebsd.misc
Subject: Re: Weird arithmetic
Date: 29 Apr 1996 22:27:26 GMT
Organization: Private FreeBSD site, Dresden
Lines: 47
Message-ID: <4m3foe$3db@uriah.heep.sax.de>
References: <4m0cqq$bv0@gap.cco.caltech.edu>
Reply-To: joerg_wunsch@uriah.heep.sax.de (Joerg Wunsch)
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stan@bombay.gps.caltech.edu ("Stan") writes:
>There is a variable called ms:
>
>(gdb) print ms
>$2 = 1.4101357041089591
>
>This looks reasonable. Taking sin(ms) worked all right, but when we try
>to take sin(2*ms), all hell breaks loose. I tried isolating the problem by
>adding a line:
>
>x1 = 2*ms;
>I suspect that there is something very fundamental that I'm missing here.
>Anybody know what it is?
Are you using <math.h>?
j@uriah 97% cat foo.c
#include <stdio.h>
#include <math.h>
int
main(void)
{
double ms, x1;
ms = 1.4101357041089591;
x1 = 2 * ms;
printf("ms = %lf, x1 = %lf\nsin(ms) = %lf, sin(x1) = %lf\n",
ms, x1, sin(ms), sin(x1));
return 0;
}
j@uriah 98% cc foo.c -lm
j@uriah 99% ./a.out
ms = 1.410136, x1 = 2.820271
sin(ms) = 0.987122, sin(x1) = 0.315820
I can't find anything bogus in the above.
--
cheers, J"org
joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ -- NIC: JW11-RIPE
Never trust an operating system you don't have sources for. ;-)