Simplest way to do parallel replicate

Question

I am fond of the parallel package in R and how easy and intuitive it is to do parallel versions of apply, sapply, etc.

Is the

Answer 1

Using clusterEvalQ as a model, I think I would implement a parallel replicate as:

parReplicate <- function(cl, n, expr, simplify=TRUE, USE.NAMES=TRUE)
  parSapply(cl, integer(n), function(i, ex) eval(ex, envir=.GlobalEnv),
            substitute(expr), simplify=simplify, USE.NAMES=USE.NAMES)

The arguments simplify and USE.NAMES are compatible with sapply rather than replicate, but they make it a better wrapper around parSapply in my opinion.

Here's an example derived from the replicate man page:

library(parallel)
cl <- makePSOCKcluster(3)
hist(parReplicate(cl, 100, mean(rexp(10))))