Having just downloaded the latest code from svn trunk, I
> started to look at the courses/ directory and was delighted
> to see all the documentation in .lyx format. However, when I
> tried to export to pdflatex I discovered that all the .png
> images in figs/ have damaged headers.
> They also do not display or convert.
I think the PNG corruption happened in the cvs to svn migration.
These files are from a short course that Fernando and I put together
which was a general introduction to scientific computing in python,
and so it is not just matplotlib. We can probably provide you with a