ggplot is one of the most famous library in R and I use it very ofen in daily workflow. But there are three topics I seldomly touch before: legend, label and font size. One reason is that they are not a necessity in out plot. But I believe it is good to be packed in our back...
ggplot(iris,aes(x=Sepal.Length,y=Sepal.Width,fill=Species))+geom_bar(stat="sum") show.legendparameter, with fine control by using a named vector: show.legend logical. Should this layer be included in the legends? NA, the default, includes if any aesthetics are mapped. FALSE never include...