Plotting a collection of variables on a grid in R

Question

I would like to learn a good way to plot a collection of variables p (dataframe columns) into a grid rather than writing out each variable into the grid.arrange function.

p <- c()
for (i in 1:length(names(df)) - 1){
  p[i] <- qplot(df[i])
}
grid.arrange(p, ncol = 5)

I want a method for: grid.arrange(p[1], p[2], ..., p[n] ) to plot each graph in a grid.

Answer 1

pl = replicate(5, ggplot(), simplify = FALSE)
grid.arrange(grobs = pl)

Note that your strategy could use a few improvements:

• preallocating p would be better with p = vector(length = ncol(df)-1, mode="list")
• p[[i]] <- not p[i] <-
• 1:3 - 1 produces 0 1 2 , and 0 isn't a valid index
• it's easier to work with long format data frames (tidy data) in ggplot/R; try reshape2::melt() or tidyr::gather() and alternatives, so that you can avoid an awkward loop over column names