R: saving ggplot2 plots in a list

Question

I am writing a R code that allows users to select columns from a data and plots histograms for each of them. Hence, I am using a \'for\' loop to generate the required number

Answer 1

Instead of mapping aesthetics using aes, you might be better off using aes_string:

 for(i in 1:length(u))
 {
   probabilityHistogram <- ggplot(plotData, aes_string(x=names(plotData)[i]))
   histogramList[[i]] <-  probabilityHistogram + geom_histogram(aes(y=..density..),     binwidth=bw, colour='black', fill='skyblue') + geom_density() + scale_x_continuous(names(plotData)[i]) + opts(legend.position='none')
 }

That worked for me, at least. This avoids having to subset your data and allows you to reference the column you want to plot by quoted name.