RE: Random seed (RANDOMIZE)

From: Chris Theis <Christian.Theis_at_cern.ch>
Date: Tue, 28 Jun 2011 16:35:20 +0000

Alberto,

> You can input any number you want: how can it be more flexible???

from the user's point of view it would be more flexible if the user did not
  have to input different seeds but the program makes sure by itself that
different runs are initiated with different values. The feature of reproducability,
which is without any question important for development and sometimes
also for a user, could be retained by specifically requesting it.

Most of the time the user is not interested in reproducing the random number
sequence and choosing a "good" seed is not necessarily trivial, depending
on the mathematical details of the RNG implementation. By the way, did you
ever investigate the influence of the chosen seeds on the cross-correlation
and the period of the implemented RNG? In case you do have test results or
some references for the one that is used I'd be interested and appreciate if
you would be willing to share them with me.

Cheers
Chris

-----Original Message-----
From: owner-fluka-discuss_at_mi.infn.it [mailto:owner-fluka-discuss_at_mi.infn.it] On Behalf Of Alberto Fasso'
Sent: 28 June 2011 16:03
To: fluka-discuss_at_fluka.org
Cc: denis bertini
Subject: Re: Random seed (RANDOMIZE)

Denis,

can you please explain what do you mean by "not particularly flexible"?
You can input any number you want: how can it be more flexible???
What is your purpose in setting a seed from a user routine?
In any case any reference to function FLRNDM() changes the current random n=
umber. Is that what you want?

Alberto

On Tue, 28 Jun 2011, denis wrote:

> Dear Fluka experts,
>
> Could you tell me how to set a seed from a user fortran routine (
> putting a number with RANDOMIZE in the input file being not
> particularly flexible ) Thanks in advance,
>
> Denis Bertini
Received on Wed Jun 29 2011 - 16:34:05 CEST

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