14.9 Prepare the Data for Display in a Graph

The recursive-lengths-list-many-files function returns a list of numbers. Each number records the length of a function definition. What we need to do now is transform this data into a list of numbers suitable for generating a graph. The new list will tell how many functions definitions contain less than 10 words and symbols, how many contain between 10 and 19 words and symbols, how many contain between 20 and 29 words and symbols, and so on.

In brief, we need to go through the lengths’ list produced by the recursive-lengths-list-many-files function and count the number of defuns within each range of lengths, and produce a list of those numbers.