Subject: primep, other systems and randoms. [VERY LONG]
From: Pedro Fortuny Ayuso
Date: Tue, 30 Apr 2002 12:19:08 +0000
FWIW: Several primality tests:
******
****** a) maxima on linux (Slackware-x86 8.0):
******
==================================
ansers given in no time:
GCL (GNU Common Lisp) Version(2.4.0) Sat Jul 14 20:25:59 GMT 2001
Licensed under GNU Library General Public License
Contains Enhancements by W. Schelter
Maxima 5.9.0pre-cvs (with enhancements by W. Schelter).
Licensed under the GNU Public License (see file COPYING)
(C1) primep(80630964769);
(D1) FALSE
(C2) primep(80630965313);
(D2) TRUE
(C3) primep(340282366762482138434845932244680310783);
(D3) FALSE
===================================
first two answers given in no time, third computation aborted after several
minutes' waiting:
~$ maxima.clisp
Maxima 5.9.0pre-cvs (with enhancements by W. Schelter).
Licensed under the GNU Public License (see file COPYING)
(C1) primep(80630964769);
(D1) TRUE
(C2) primep(80630965313);
(D2) TRUE
(C3) primep(340282366762482138434845932244680310783);
===================================
maxima on debian-x86 2.2, but a different computer (and as you
can see, a different gcl, etc...).
The answers were given in almost no time:
$ ./local/binnoether/maxima
GCL (GNU Common Lisp) Version(2.5.0) Wed Feb 6 15:03:58 GMT 2002
Licensed under GNU Library General Public License
Contains Enhancements by W. Schelter
Maxima 5.9.0pre-cvs (with enhancements by W. Schelter).
Licensed under the GNU Public License (see file COPYING)
(C1) primep(80630964769);
(D1) FALSE
(C2) primep(80630965313);
(D2) TRUE
(C3) primep(340282366762482138434845932244680310783);
(D3) FALSE
(C4)
******
****** b) other systems on linux:
******
Maple 6 on linux (Debian-x68 2.2) (but a different computer
due to licesing issues). Answers given in no time.
# maple
|\^/| Maple 6 (IBM INTEL LINUX)
._|\| |/|_. Copyright (c) 2000 by Waterloo Maple Inc.
\ MAPLE / All rights reserved. Maple is a registered trademark of
<____ ____> Waterloo Maple Inc.
| Type ? for help.
> isprime(80630965313);
true
> isprime(80630964769);
true
> isprime(340282366762482138434845932244680310783);
true
===================================
REDUCE 3.7 on linux x86 Debian2.2 (same comp. as Maple).
The answers were given in no time.
# reduce
Loading image file :/usr/local/reduce/pred37/lisp/psl/linux/red/reduce.img
REDUCE 3.7, 15-Apr-1999 ...
1: factorize(340282366762482138434845932244680310783);
{{340282366762482138434845932244680310783,1}}
2: factorize(80630964769);
{{80630964769,1}}
3: factorize(80630965313);
{{80630965313,1}}
*********************************************
*********************************************
Whereas, from:
http://wims.unice.fr/wims/wims.cgi
80630964769 = 80630964769
is a (certified) prime.
80630965313 = 80630965313
is a (certified) prime.
Yes, 340282366762482138434845932244680310783 passes the rigorous primality
test, therefore is really a prime.
**********************************************
**********************************************
The differences should (AFAIK) be in the algorithms for generating random
numbers. But I have not looked at the code yet. It could also be a bug in
gcl. Clisp, after more than 30min did not give an answer for the long one. I
wonder what it is doing (?).
Cheers to all,
Pedro.
--
Pedro Fortuny Ayuso -------------> www.maths.qmul.ac.uk/~pf
School of Mathematical Sciences. Queen Mary College, Univ. London
Mile End Road, London E1 4NS, UK ------> www.qmul.ac.uk
P.Fortuny@maths.qmul.ac.uk Tfn. Nr. 44 20 7882 5493