simple_progress_bar.R

#Load Libraries
library(foreach)
library(utils)
library(iterators)
library(doParallel)

#Choose number of iterations
n <- 1000

#Progress combine function
f <- function(){
  pb <- txtProgressBar(min=1, max=n-1,style=3)
  count <- 0
  function(...) {
    count <<- count + length(list(...)) - 1
    setTxtProgressBar(pb,count)
    Sys.sleep(0.01)
    flush.console()
    c(...)
  }
}

#Start a cluster
cl <- makeCluster(4, type='SOCK')
registerDoParallel(cl)

# Run the loop in parallel
k <- foreach(i = icount(n), .combine=f()) %dopar% {
  log2(i)
}

head(k)

#Stop the cluster
stopCluster(cl)

Possible slow