This is an idea that’s been kicking around in my head for awhile. Basically, the Axes class is way too expansive. Nelle made a major step in the right direction with a PR that split it up into plotting and non-plotting methods:
https://github.com/matplotlib/matplotlib/pull/1931/files
What I’d like to see is something that further separates plotting methods into many smaller sub-modules/-packages. Organizing the code this way would make it easier (for me at least) to read, understand, and make changes to the code.
I think that this could be done in an API-compatible way. In fact, a few of the plotting methods are already implemented this way: In other words, the bulk of the methods are implemented as functions outside of Axes, and the Axes methods that are just thin wrappers around those functions (or classes). See, for example, streamplot, barbs, and quiver methods
The examples mentioned above simply take the axes as the first parameter. Here’s the Axes-method definition of quiver, for example:
def quiver(self, *args, **kw):
…
q = mquiver.Quiver(self, *args, **kw)
…
return q
(might be a good idea to add a decorator to maintain the function signature and docstring)
This should work for any of the plotting methods (I would imagine). Another alternative is for all these plotting functions to have an ax (or some other spelling) keyword argument that defaults to None and then have a line in every function that does something like
ax = ax if ax is not None else plt.gca()
If I’m not mistaken, this would allow pyplot functions to be even thinner wrappers around these newly extracted functions. (In some cases, it might just be a simple import from the the new sub-package/-module into the pyplot namespace).
I haven’t sat down and thought through all the details of such a change, but I wanted to throw it out there to see if anything sticks.
Cheers,
-Tony
