There is a package Parallel
detectCores(): return how many cores exist on your PC.
cl <- makeCluster(np): initialize a cluster mc with np processes.
Apply Operations using Clusters:
clusterCall, clusterEvalQ, clusterApply, clusterExport, clusterMap,
parLapply, parSapply, parApply, parRapply, parCapply
stopCluster(cl): release the occupied cores.
An example
Check how many cores exist on my PC.
library(parallel)
detectCores()## [1] 12Define a function.
sim <- function(x){
rnorm(1, mean = x)
}Use parallel to speed up the calculation.
SimParallel <- function(x, nc){
cl <- makeCluster(nc)
result = parSapply(cl = cl, x, sim)
stopCluster(cl)
return(result)
}
out <- SimParallel(1:10000, 8)