Get identical results for parallel and sequential?

Hi All,

I have a question about R parallel computing by using snowfall.

How can I set the seeds on parallel workers to get the same result as
sequential mode?

As Hana S said, the snowFT package has the ability to assign seeds to
"replications", unlike other methods, which assign seeds to compute
nodes.  By associating seeds to replications, it is thus assured that
each time a step runs, it gets same seed, no matter on which node.

I've been trying to generalize that idea to allow multiple (separate)
streams of random numbers for each replication.  We have several
projects where the replication requires the "exact same random
numbers" from each of several streams. You could try this out and let
me know if it works for your purpose.

http://winstat.quant.ku.edu/svn/hpcexample/trunk/Ex66-ParallelSeedPrototype

If the README doesn't seem clear, email me, I will fix it up.

pj

For example:

sfSapply(c(1,1),rnorm)

[1] ?1.823082 -2.222052

rnorm(2)

[1] -0.5179967 -1.0807196

How to get the identical result?

Thanks.
Libo

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Paul E. Johnson
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