Embedding Matplotlib images into wxPython

[dr_tyson at hotmail.com]

Well, to answer my own question, the problem turned out to be that I
was using the 'wx' backend and not the 'wxagg' one. Attempting to use
the former typically resulted in a not implemented error upon the call
to imshow. I was working from an older set of matplotlib example files
which didn't include the dynamic image with wxagg demo. Thank goodness
for those examples! No better way to learn how to implement code.