Maarten writes: > I do recommend you read http://docs.python.org/howto/doanddont.html as a starting point to avoid learning some bad habits, especially on importing. You probably already found https://www.cfa.harvard.edu/~jbattat/computer/python/science/idl-numpy.html Yikes! I'm sure that first reference is in English, but I don't have much of an idea what it means yet. :-) I have found the second reference very helpful. I've bookmarked both of these for future consideration. Thanks for your good advice. Cheers, David