The initial setup to make a bar plot is a little more complicated in ggplot() than in barplot2(), but the result is more visually appealing. Moreover, plotting with ggplot2 requires a little more code than when plotting with base graphics.

• First, we must define where our data is found (data=RP.means).
• Next, we must explain aesthetics. This is where we state which data will go on the x-axis and y-axis and which variable we want to fill in our bars with color. The aesthetics all go within a function called aes().

One of the things that can be difficult to wrap our head around when plotting with ...