Our goal is to construct a graph showing the numbers of function definitions of various lengths in the Emacs lisp sources.
As a practical matter, if you were creating a graph, you would
probably use a program such as gnuplot to do the job.
(gnuplot is nicely integrated into GNU Emacs.) In this case,
however, we create one from scratch, and in the process we will
re-acquaint ourselves with some of what we learned before and learn
more.
In this chapter, we will first write a simple graph printing function. This first definition will be a prototype, a rapidly written function that enables us to reconnoiter this unknown graph-making territory. We will discover dragons, or find that they are myth. After scouting the terrain, we will feel more confident and enhance the function to label the axes automatically.