Set hexbin default linecolor to 'face'

[dstansby]

Fixes #7185

[NelleV]

Hi @dstansby
The patch looks good overall, but there are pep8 incompatible changes added. Also, can you document those changes in the default change section
(doc/users/dflt_style_changes.rst) and what's new section (doc/users/whats_new/README.rst).
Thanks

[NelleV]

This line is too long for pep8. It should be 79 char or less.

[dstansby]

I'm currently struggling to find a way to split it on to two lines without the 2nd line just becoming part of the paragraph underneath... Any ideas?

[tacaswell]

This is an acceptable place to use \ to break the doc line.

[NelleV]

something like
edgecolors : {"face", "none", None, color}, optional, default: "face" would also have been acceptable.

[tacaswell]

This should note that the default behavior has not changed (just the meaning of 'none').

[efiring]

On 2016/11/23 10:34 AM, Thomas A Caswell wrote:

@tacaswell commented on this pull request.

---

In lib/matplotlib/axes/_axes.py
#7500:

@@ -4163,10 +4163,12 @@ def hexbin(self, x, y, C=None, gridsize=100, bins=None,
linewidths : scalar, optional, default is None
If None, defaults to 1.0.

•    edgecolors : {'none'} or mpl color, optional, default is 'none'
  

•        If 'none', draws the edges in the same color as the fill color.
  

•        This is the default, as it avoids unsightly unpainted pixels
  

•        between the hexagons.
  

•    edgecolors : {'face', 'none', _None_} or mpl color, optional, default is 'face'
  

This is an acceptable place to use || to break the doc line.

Or just leave out the "optional"? After all, specifying the default
only makes sense if it is optional.
Alternatively, a reasonable convention would be to say that if the
default is not specified on an optional parameter, the default is the
first entry in the list of possibilities.

[QuLogic]

the default is the first entry in the list of possibilities.

That's how Numpydoc already defines arguments that take a restricted set of inputs.

[NelleV]

Thanks for the patch @dstansby !