Message-ID: <17393.47298.547406.294122@musil.localdomain>
Date: 2006-02-14T11:02:26Z
From: Jasjeet Singh Sekhon
Subject: Parallel computing in R for dummies--how to optimize an external model?
In-Reply-To: <7E4C06F49D6FEB49BE4B60E5FC92ED7A038CB86F@pnlmse35.pnl.gov>
Hi Scott,
It is difficult to debug your issue without more information. Would
it be possible to email me code of a simple example?
Cheers,
Jas.
=======================================
Jasjeet S. Sekhon
Associate Professor
Travers Department of Political Science
Survey Research Center
UC Berkeley
http://sekhon.polisci.berkeley.edu/
V: 510-642-9974 F: 617-507-5524
=======================================
Waichler, Scott R writes:
>
> I am trying to use the optimizing function genoud() with the snow
> package on a couple of i686 machines running Redhat Linux WS4 . I don't
> know anything about PVM or MPI, so I just followed the directions in
> snow and rgenoud for the simplest method and started a socket cluster.
> My function fn for genoud involves updating an input file for a separate
> numerical model with the latest parameter set from the optimizer,
> running the (compiled) model on the input file with system(), and
> processing the output including calculation of objective function. The
> whole process works on the localhost machine in one cpu, and I can see
> that an R session is created in the second, non-localhost machine, but
> it doesn't seem to be doing anything. All of the model runs generated
> by the application of genoud take place in the cpu. What am I missing?
> I can see where there would be a conflict in having multiple processors
> trying to access the same system model input file at once, but I don't
> see any indication of that type of problem.
>
> Grateful for any help,
>
> Scott Waichler
> Pacific Northwest National Laboratory
> scott.waichler at pnl.gov
>
>