Matplotlib dependency not listed in setup.py about starlink-pyast

[timj]

Sorry about that. I'll take a look.

[timj]

I've had a quick look and I think I would be inclined to fix the Atl interface so that it does something like:

try:
    import starlink.Grf as Grf
except ImportError:
    Grf = None

and then raise an exception in the plotframeset routine if Grf is None. Ideally we would have put the ATL plot routines in a different support package but it's a bit late to do that now.

[rmjarvis]

I suppose that would solve the problem, but it seems less than ideal from an end user's perspective, since it swallows the traceback for the ImportError. If the user thought they had matplotlib installed, this wouldn't give them any feedback as to why import starlink.Grf is failing.

Why not just put import starlink.Grf in the plotframeset function itself? Is this just to conform to PEP8, or is there a more concrete reason to prefer putting this at the top?

Remember, "A foolish consistency is..." not always the best choice. :)

[timj]

Hmmm. Yes, I tend to prefer imports at the top of code files rather than buried in the middle, but in this case, given that the failure mode is identical (you get an unexpected error some time after your program starts rather than at import time), I guess having the real error trigger inside plotframeset is better than an error we make up ourselves when plotframeset is called.

[timj]

Ok, I'm sleep-addled but I've put in an attempted fix in #15.