pyplot.plotfile. gridon option added with default from rcParam.

[montefra]

This should be a clean pull request of issue: #1205

Recap: the original plotfile function draw the axes grids at each call. This pull request implements a
keywords to enable or disable the grid. The default is taken from rc.Params['axes.gris'].
This keyword is deprecated and will be deleted from future releases

[dmcdougall]

Thanks for that, @montefra. If you ever need to update this pull request you can do the following:

1. Make sure you are currently on the plotfile_grid branch:

git checkout plotfile_grid

2. Make any changes you want:

git add ...
git commit

3. Push the branch:

git push origin plotfile_grid

The updates will display here automagically.

[dmcdougall]

@efiring You had concerns about this change hurting users. Would an entry in api_changes.rst address those concerns, or would a warning be more appropriate?

[dmcdougall]

I think you lost some indentation here.

[montefra]

I thought that too. But if you go to my repository (https://github.com/montefra/matplotlib/blob/plotfile_grid/lib/matplotlib/pyplot.py) ax.grid(gridon) has the right indentation.
Can be a problem with tabs. I use vim with some selfindent and it seems that it converts spaces to tabs when they are many.
I've tested the code before submitting and didn't get any indent error. I can substitute the tab with spaces and recommit if it's a problem.

[WeatherGod]

On Sunday, September 23, 2012, Francesco Montesano wrote:

In lib/matplotlib/pyplot.py:

@@ -2189,8 +2192,7 @@ def getname_val(identifier):
elif i==1:
ax = fig.add_subplot(1,1,1)

- ax.grid(True)

•   ax.grid(gridon)
  

I thought that too. But then if you go to my repository (
https://github.com/montefra/matplotlib/blob/plotfile_grid/lib/matplotlib/pyplot.py)
ax.grid(gridon) has the right indentation.
Can be a problem with tabs. I use vim with some selfindent and it seems
that it converts spaces to tabs when they are many.
I've tested the code before submitting and didn't get any indent error. I
can substitute the tab with spaces and recommit if it's a problem.

Do a google search for "python vimrc options", and you will find an
appropriate set of options to use. They will work properly even with self
indent.

[efiring]

This is very confusing, despite being a tiny change. From reading the predecessor, #1205, I gathered that the decision was to just make the jump: leave out the new kwarg, and use the rcParams value internally, for consistency with other plotting. However, this PR has the kwarg back in. Furthermore, it is used in a particularly confusing way, such that only the rcParams value at the time the function is defined takes effect; changing the rcParams value before the function is called will not affect the function:

In [1]: x = dict(a=1)
In [2]: def f(xx=x['a']):
   ...:     print xx
   ...:     
In [3]: f()
1
In [4]: x['a'] = 2
In [5]: f()
1

It looks like the best way to handle this is going to be to make a clean break--knowing it may cause some presumably minor breakage (changing plot appearance, not information content) in user code. So I think we need to leave the kwarg out, and simply use the rcParams value internally. This requires a note in api_changes.

If @mdboom or others would prefer not to make this api change (which is almost a bug fix; it is repairing a design flaw in plotfile) for v1.2, then it (meaning not the present PR, but the tiny change outlined above, as a clean single changeset to whichever version is selected as the target) can be targeted to master instead. It's not urgent.

[dmcdougall]

@montefra Could you update this to be in line with @efiring's suggestion?

[montefra]

@dmcdougall: gridon removed. I also think that is neater if plotfile works as all the other pyplot functions
@efiring 👍 I didn't know that function arguments are evaluated a definition time, not at execution time.

[dmcdougall]

@montefra You'll also need to add a little note in api_changes.rst warning users of the new behaviour.

Edit: grammar.

[montefra]

@dmcdougall done. I hope the the English is good enough

[dmcdougall]

@montefra Thanks. Can you squash all this down to a single commit?

[montefra]

@dmcdougall done without making a mess.