Ever since Hans Rosling presented a motion chart to tell his
story of the wealth and health of nations, there has been an
affinity for proportional bubbles on an x-y axis. This tutorial
is for the static version of the motion chart: the bubble chart.
The goal of Chernoff faces is to show a bunch of variables at
once via facial features like lips, eyes, and nose size. Most of
the time there are better solutions, but the faces can be
interesting to work with. Oftentimes, you'll want to fit a line
to a bunch of data points. This tutorial will show you how to do
that quickly and easily using open-source software, R.