I got some requests to share the MetaPost sources I use. The reason I haven't done this right away is that I haven't cleaned it up. At all. It's not parametrized, nothing. So far I copy the figure definition and reuse them. The change are minimal each time but that's it. I still haven't cleaned it up and probably won't so some time. So, the source for two graph types is here. The result looks like this: