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Re: st: AW: how to cancel the seed set previously?


From   Maarten buis <maartenbuis@yahoo.co.uk>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: AW: how to cancel the seed set previously?
Date   Thu, 2 Jul 2009 08:50:20 +0000 (GMT)

--- gjhxmu@sina.com wrote:
> 2. how to cancel the seed set previously? Maybe next time I
> again want to produce uniformly distributed random variates, 
> and set seed 100 by accident, which may lead to the variates 
> produced is not random.

Computers on their own can't produce truly random numbers. 
They are determininistic sequences of numbers that mimic a
sequence that would occur randomly. A lot of effort has gone
into creating these (pseudo) random number generators and 
they are now very good at mimicing a (truly) random proces. 
The advantage of using these deterministic sequences is that 
your results are reproducable. So, I would consider it a 
feature that you get the same sequence of numbers if you
"by accident set the seed at 100 again". This sequence still
mimic the behavior of a truly random number, so you don't 
have to worry that this "may lead to the variates produced 
is not random."

Hope this helps,
Maarten

Ps. A fun way of creating truely random numbers is:
http://gamesbyemail.com/News/DiceOMatic

-----------------------------------------
Maarten L. Buis
Institut fuer Soziologie
Universitaet Tuebingen
Wilhelmstrasse 36
72074 Tuebingen
Germany

http://home.fsw.vu.nl/m.buis/
-----------------------------------------
 



      

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