We might want to remove these files from git and explicitly ignore them. As a general rule, you shouldn't include automatically generated files under source control (rather, use a script to generate them).  Since these aren't really needed as input or as expected, maybe we want to remove them?

Then again, they do kind of help with debugging-- we can see what the output should be by having a graphical representation of the input. Still, I think they should be removed from source control and we should just add a little script that generates the graphs from the binary files.