I have a set of survey data, and I'd like to generate plots of a particular variable, grouped by the respondent's country. The code I have written to generate the plots so far is:

countries <- isplit(drones, drones$v3)
foreach(country = countries) %dopar% {
  png(file = paste(output.exp, "/Histogram of Job Satisfaction in ", country$key[[1]], ".png", sep = ""))
  country.df <- data.frame(country)  #ggplot2 doesn't appreciate the lists nextElem() produces
  ggplot(country.df, aes(x = value.v51)) + geom_histogram()
  dev.off()
}

The truly bizarre thing? I can run the isplit(), set country <- nextElem(countries), and then run through the code without sending the foreach line - and get a lovely plot. If I send the foreach, I get some blank .png files.

I can definitely do this with standard R loops, but I'd really like to get a better grasp on foreach.

r foreach ggplot2
Edit
Report