[R-sig-hpc] How to attain randomness and reproducibility

[David Lundquist]

Currently, I am using the foreach package in R to do the following (in
R-flavored pseudocode):

*set.seed(1)*
*foreach square in big grid of parameter combinations **%dopar%*
*     foreach i in 1:replication_count **%do%*
*            do some computation, output a row, and rbind it*
*save the df generated by rbinding*

Possible virtues of the preceding: seed is made clear
Possible vices of the preceding: failure of randomness

One might therefore try moving set.seed to the inner loop:

*foreach square in big grid of parameter combinations %dopar%*
*     foreach i in 1:replication_count **%do%*
            *set.seed(i)*
*            do some computation, output a row, and rbind it*
*save the df generated by rbinding*

Possible virtues of the preceding: seed sequence is explicit
Possible vices of the preceding: we've programmed the seeds to be equal

I'd appreciate any advice, especially if there's an easy reference/vignette
that can be pointed to, a la

https://cran.r-project.org/web/packages/doRNG/vignettes/doRNG.pdf
https://cran.r-project.org/web/packages/dqrng/vignettes/parallel.html

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