Newsgroups: comp.ai.genetic
From: thasan@mayfair.demon.co.uk ("V.K. Thasan")
Path: cantaloupe.srv.cs.cmu.edu!das-news2.harvard.edu!news2.near.net!news.mathworks.com!hookup!swrinde!pipex!demon!mayfair.demon.co.uk!thasan
Subject: Re: random number generator
References: <1994Apr25.205100.6167@cc.ic.ac.uk> <2pit91$4co@rockall.cc.strath.ac.uk> <2pjc6t$9l9@lns540.lns.cornell.edu> <1994May5.144420.11829@cs.yale.edu>
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Date: Thu, 27 Oct 1994 16:46:44 +0000
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In article <1994May5.144420.11829@cs.yale.edu>
           cs90mdr@ccws-27.brunel.ac.uk "Michael D Robinson" writes:

>Jesse A Ernst (jae@lns598.lns.cornell.edu) wrote:
>
>: You should be especially careful when combining numbers from the same seed
>:  (i.e. if you perform an operation that involves more than one random number)
>: for example, if you have a loop in your program where you throw two random...
>: numbers and combine them in some way.  Doing this tends to magnify the
> problems
>:  in some generators.  The solution is to run copies (two in this example) of 
>: the generator and take numbers that will be combined from different lists.
>
>:            -Jesse
>
>
>This may seem like a dumb question, but as a newcomer to GA's
>can someone tell me what a 'seed' is in a random GA generator,
>
>and does anyone know of any advanatage/disadvantage in using
>the predefined rand() function in C from stdlib.h.
>I've used it and it seems OK.
>
>Thanks, Dave Robinson.
>

Seed is basically an initializing value for a random sequence. That is each 
seed will typically result in a different random sequence. The same 
initializing seed value will always return the same random sequence, however.

 (Refer Numerical Receipes in C for more details)

        - Thasan. 
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