Bar plot of the percentage of null counts per sample
barplotNull(counts, group, col = c("lightblue", "orange", "MediumVioletRed",
"SpringGreen"), outfile = TRUE)matrix of counts
factor vector of the condition from which each sample belongs
colors of the bars (one color per biological condition)
TRUE to export the figure in a png file
A file named barplotNull.png in the figures directory