[matplotlib-devel] Add `streamplot` function

[Tony Yu <ts...@gm...>]

I just submitted a pull request to add a `streamplot` function to plot the
streamlines of a vector field. This implementation is a modified version of
the streamplot function posted to the list by Tom Flannagan [1].

This PR isn't complete, but I wanted to submit it in order to get comments.
In particular:

* I haven't added the pyplot function, only the axes method. It looks like
the pyplot function should be generated by some boiler plate code.

* I'm not sure what the docstring conventions are (the code isn't terribly
consistent), so I just (more-or-less) followed the numpy docs.

* Some parameter that probably should be adjustable aren't at the moment
(e.g. max streamline length, some arrow properties).

* I left the original copyright from Tom's implementation, but I don't know
if the BSD license has anything to say about that.

I'm not totally familiar with the matplotlib architecture so I'm probably
forgetting a number of things. Feedback appreciated.

-Tony

[1]
http://www.mail-archive.com/mat...@li.../msg20208.html