Still bug in Random
- To: mathgroup at smc.vnet.net
- Subject: [mg61742] Still bug in Random
- From: "Pedrob P.B. de Oliveira" <pedrob at mackenzie.br>
- Date: Fri, 28 Oct 2005 03:25:21 -0400 (EDT)
- Reply-to: "Pedrob P.B. de Oliveira" <pedrob at mackenzie.br>
- Sender: owner-wri-mathgroup at wolfram.com
I've just tried Mathematica 5.2 in respect to an old bug in Random[ ], as
pointed out in the Mathgroup posting
Subject: [mg61742] [mg47333] bug in Random
From: Veit Elser <ve10 at cornell.edu>
To: mathgroup at smc.vnet.net
and the bad news is that the bug remains...
The problem is a correlation in the random numbers generated from running
the expressions
r=Table[Random[Integer,{1,2^62}],{10^5}];
Union[Table[r[[i]]+r[[i+24]]-r[[i+20]],{i,10^5-24}]]
which, surprisingly, yields simply
{-2147483647, 1, 2147483649, 4611686016279904256,4611686018427387904,
4611686020574871552}
By the way, last year I got in touch with WRI's support in respect to the
bug and, after about 2 months awaiting, all I could get as a reply was a
workaround that, disapointingly, had been proposed in Mathgroup in 2000...!!
This is really weird...
..Pedro
Pedro P.B. de Oliveira
Universidade Presbiteriana Mackenzie
Faculdade de Computação e Informática & Pós-Graduação em Engenharia Elétrica
Rua da Consolação 896, Consolação
01302-907 São Paulo, SP - Brazil
Email: pedrob at mackenzie.br
Web: www.mackenzie.br/pedrob
Phone: +55 (0)11 3236-8711
Fax: +55 (0)11 3236-8600