[CIG-LONG] CIG-LONG Digest, Vol 16, Issue 6

[Thorsten Becker]

Hi,

Interesting symmetry break... 

If the random number generator is indeed the cause of these
discrepancies, I think it would be preferable to have exactly the same 
pseudo-random numbers each time, as controlled by a specific random
number seed that would be a parameter (E.g. numerical recipes ran2, or
whatever is better.) 

If the user does indeed want to be surprised each time, maybe seeding
with "date" could take the seconds since 1970 as seed, or something
like that, as is often done.

Cheers

Thorsten



>    3. gale : 1 input, 4 different outputs (js at cp.dias.ie)
> 
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Message: 3
Date: Tue, 26 Feb 2008 14:54:04 -0000 (GMT)
From: js at cp.dias.ie
Subject: [CIG-LONG] gale : 1 input, 4 different outputs
To: cig-long at geodynamics.org
Message-ID: <49030.160.6.1.47.1204037644.squirrel at webmail.dias.ie>
Content-Type: text/plain; charset="iso-8859-1"

Hi,
I recently ran the same model in Gale four times and it generated
four differing outputs. While run 1 and run 3 are quite similar, as are
run 2 and run 4, 1 and 3 both differ significantly from 2 and 4. When
Gale generates the material points for a model, does it do so randomly?
Is this the reason for the differences? If so, is it possible to use
the starting locations of the material points from one model in another
future model?

Thank you for your time,
regards,

john.

-- 
Thorsten Becker                   Department of Earth Sciences 
University of Southern California                 213.740.8365
Los Angeles CA 90089-0740          geodynamics.usc.edu/~becker