How do you create a progress bar when using the “foreach()” function in R?

by

Edit: After an update to the doSNOW package it has become quite simple to display a nice progress bar when using %dopar% and it works on Linux, Windows and OS X

doSNOW now officially supports progress bars via the .options.snow argument.

library(doSNOW)
cl <- makeCluster(2)
registerDoSNOW(cl)
iterations <- 100
pb <- txtProgressBar(max = iterations, style = 3)
progress <- function(n) setTxtProgressBar(pb, n)
opts <- list(progress = progress)
result <- foreach(i = 1:iterations, .combine = rbind, 
                  .options.snow = opts) %dopar%
{
    s <- summary(rnorm(1e6))[3]
    return(s)
}
close(pb)
stopCluster(cl)

Yet another way of tracking progress, if you keep in mind the total number of iterations, is to set .verbose = T as this will print to the console which iterations have been finished.

Previous solution for Linux and OS X

On Ubuntu 14.04 (64 bit) and OS X (El Capitan) the progress bar is displayed even when using %dopar% if in the makeCluster function oufile = "" is set. It does not seem to work under Windows. From the help on makeCluster:

outfile: Where to direct the stdout and stderr connection output from the workers. “” indicates no redirection (which may only be useful for workers on the local machine). Defaults to ‘/dev/null’ (‘nul:’ on Windows).

Example code:

library(foreach)
library(doSNOW)
cl <- makeCluster(4, outfile="") # number of cores. Notice 'outfile'
registerDoSNOW(cl)
iterations <- 100
pb <- txtProgressBar(min = 1, max = iterations, style = 3)
result <- foreach(i = 1:iterations, .combine = rbind) %dopar% 
{
      s <- summary(rnorm(1e6))[3]
      setTxtProgressBar(pb, i) 
      return(s)
}
close(pb)
stopCluster(cl)

This is what the progress bar looks like. It looks a little odd since a new bar is printed for every progression of the bar and because a worker may lag a bit which causes the progress bar to go back and forth occasionally.

More Related Contents:

  1. How can I print when using %dopar%
  2. Saving multiple outputs of foreach dopar loop
  3. reading global variables using foreach in R
  4. Filter data.frame rows by a logical condition
  5. How to prevent ifelse() from turning Date objects into numeric objects
  6. Evaluate expression given as a string
  7. Split column at delimiter in data frame [duplicate]
  8. Cluster analysis in R: determine the optimal number of clusters
  9. Select groups based on number of unique / distinct values
  10. Scheduling R Script
  11. How to send an email with attachment from R in windows
  12. How to create example data set from private data (replacing variable names and levels with uninformative place holders)?
  13. R ifelse to replace values in a column
  14. finding point of intersection in R
  15. Unable to load rJava on R
  16. Sum all values in every column of a data.frame in R
  17. ggplot2 multiple scales/legends per aesthetic, revisited [duplicate]
  18. Create categorical variable in R based on range
  19. Apply several summary functions (sum, mean, etc.) on several variables by group in one call
  20. Order of operator precedence when using “:” (the colon)
  21. Determining UTM zone (to convert) from longitude/latitude
  22. Using R to download zipped data file, extract, and import .csv
  23. Downloading png from Shiny (R)
  24. Layered axes in ggplot?
  25. Count unique values for every column
  26. R data.table breaks in exported functions
  27. Remove part of a string in dataframe column (R)
  28. How to remove strange characters using gsub in R? [duplicate]
  29. R, car package unable to load
  30. Failure to connect to odbc database in R

Leave a Comment