Quick Plots
In some cases, you will want to create a quick plot with a minimum of typing.
In these cases you may prefer to use qplot() over ggplot(). qplot() lets you
define a plot in a single call, picking a geom by default if you don’t supply
one. To use it, provide a set of aesthetics and a data set:
qplot(displ, hwy, data = mpg)
qplot(displ, data = mpg)