Examples of Existing Plot Devices. An illustration of some popular plotting techniques for distributional data. Panels a-c show horizontal boxplots; panels d-f show histograms; panels g-h show probability density plots. Plots in column 1 were constructed based on a sample of 1000 from an N(10, 1) distribution. Plots in column 2 were constructed based on a mixture; 500 drawn from N(5, 1) and 500 from N(15, 1). Column 3 applies these same plots to microarray data. The RMA algorithm was performed using 6 chips from the Affymetrix HG_U133A_tag spike-in data set; mean intensities were obtained by averaging log (base 2) summary expression measures across a subset consisting of three technical replicates.