I have a set of timestamps (each corresponding to a student submission), and I wanted to take a look at them graphically. I know criterion uses a KDE and makes a nice plot, and it looks like it depends on the statistics package, which provides a kde function, but I couldn't trace through the code of criterion to see how it's being used.
Ideally, and answer would at least be a snippet of code that produces a picture. An explanation of what criterion does in this case would also be welcome.