Question

I have many data frames which are the output of the same kind of analysis but with different parameters.
I’d like to plot the data frames with ggplot, changing the main title to specify the different parameters used.

I thought about putting the data frames into a list and using lapply. But I couldn’t figure out how to change the title accordingly in lapply.

Answer 1

You could try something like this,

parameters = data.frame(p1=letters[1:5], p2=round(rnorm(5),2))
l = replicate(5, data.frame(x=1:10, y=rnorm(10)), simplify=FALSE)
names(l) = do.call(paste, c(parameters, sep=","))

plot_one = function(x)
  ggplot(data = l[[x]]) + geom_path(aes(x, y)) +
   opts(title = x)

plots = lapply(names(l), plot_one)

do.call(gridExtra::grid.arrange, plots)