Upgrade minimal version of matplotlib to 1.5.3 and use a seaborn-like style in docs

[topper-123]

Matplotlib is an optional dependency of pandas. I propose making matplotlib 1.5.3 the recommended minimal version for pandas 0.21. Currently, v1.4.3 is the minimal version.

The reason are:

• matplotlib v1.4 has support for python up to 3.4. it doesnt officially support python 3.5 or above. it's old.
• matplotlib 1.5 has support for python up to 3.5. it doesnt officially support python 3.6, but this is still better than for 1.4.
• matplotlib 1.5 has some new built-in styles, among others seaborn-like styles. IMO the ggplot-based plot that are used in the docs at present have a bit of 90-feel, while (IMO, this is subjective) the seaborn styles have a more modern feel. By upgrading the minimum version to 1.5 we could make the plots in the docs switch style to seaborn-style.
• also, matplotlib 1.5 has built-in support for labeled data (a la pandas' column names). This upgraded requirement, while it may not affect users of pandas directly, could allow some refactoring of the plotting code in pandas (disclaimer, I haven't looked at the pandas plotting code).

For differences between the different 1.x versions for matplotlib, see her.

So:

• do people support making matplotlib 1.5 the minimum recomemnded version for pandas 0.21?
• Do people support switching the plot style in docs to a seaborn style?

[topper-123]

Alternatively, if going to 1.5 is seen as too big of a change this time, could the doc plots still be built using matplotlib => 1.5 and making a note on how they're made.

[jreback]

going to 1.5.3 is fine. we don't support python 3.4.

[jreback]

note that this issue is 2 independent parts. The docs are built on 3.6 with specific requirements and can/should use the newest mpl syntax (we use the latest mpl), see requirements-3.6_DOC.build.

[topper-123]

Ok. I'll make a pull request where the style for the doc plots will have a seaborn style.

I'll assume that I only have to change the .rst files and the plots will be generated automatically (i.e. I don't have to generate each one and put them in a folder somewhere)?

[TomAugspurger]

@topper-123 seach for matplotlib.style.use('ggplot') in the rst files. And yes, the plots are generated automatically.

FWIW, I prefer the default matplotlib 2.0 style for some things like line plots. I might vote for it over 'seaborn', but would be curious what others prefer.

[topper-123]

Thanks @TomAugspurger. Then it's very easy, that's nice. I'll might wait a few days before commiting, if a discussion arises.

I personally prefer seaborn-deep, but would go with seaborn here, as that's more standard choice. I would like to keep the style consistent for the whole docs (unless there's a specific reason not to).

I could maybe add a small snippet, showing 2-3 different styles, so readers who are unfamiliar with matplotlib can get a feel for the possibilities).

[TomAugspurger]

No reason to bikeshed over this :) Feel free to submit a PR changing the style to your favorite.

…

On Tue, Sep 5, 2017 at 4:06 PM, topper-123 ***@***.***> wrote: Thanks @TomAugspurger <https://github.com/tomaugspurger>. Then it's very easy, that's nice. I'll might wait a few days before commiting, if a discussion arises. I personally prefer seaborn-deep, but will choose seaborn here, as that's more standard choice. I would like to keep the style consistent for the whole docs (unless there's a specific reason not to). I could maybe add a small snippet, showing 2-3 different styles, so readers who are unfamiliar with matplotlib can get a feel for the possibilities). — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#17423 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ABQHIkAzDYLO3H8BDCtxGXyR5QtfwYnnks5sfbfCgaJpZM4PK-JG> .

[topper-123]

This issue was done in #17462, so i'm closing the issue.