Some commands in a couple of code chunks in the book are repeated multiple times. For example, geom_point() + facet_wrap(vars(species)) + # this transforms the axes' coordinates using log10() geom_point() and y = "log10") + # this uses a nicer theme for our final plot in this chapter and violin + # this geom plots the data points with some additional (horizontal) noise to see overlapping points in this chapter.