[ENH] Implementing plot title for plot_series

[arnavrneo]

Reference Issues/PRs

Fixes #3944

What does this implement/fix? Explain your changes.

This implementation updates plotting.py under utils directory. The function plot_series is updated and now the user can enter the plot title for the figure.

Changes:

• The function plot_series now has one more parameter: suptitle (default value is None) to which user can give the title of the plot or figure.

Does your contribution introduce a new dependency? If yes, which one?

No.

PR checklist

For all contributions

⬜ I've added myself to the list of contributors.
✅ I've added unit tests and made sure they pass locally.
✅ The PR title starts with either [ENH], [MNT], [DOC], or [BUG] indicating whether the PR topic is related to enhancement, maintenance, documentation, or bug.

[chillerobscuro]

Hey @arnavrneo, this looks like a nice new feature!

Is it necessary to use suptitle instead of title when this function only makes plots with one ax?

Either way I'd suggest calling the argument title just to keep the interface as straight forward as possible, even if we do use suptitle under the hood.

[arnavrneo]

@chillerobscuro Thanks!

About suptitle or title, I read in the matplotlib documentation; about those two it stated the following:

suptitle

Add a centered suptitle to the figure.

This adds a self-centered title to the whole figure and not the axes.

title

Set a title for the Axes.
Set one of the three available Axes titles. The available titles are positioned above the Axes in the center, flush with the left edge, and flush with the right edge.

This can be used for different axes.

So, as there was just one ax in the function, I went with suptitle.

And for the arguments, you're right. It should be straight forward as possible. I'll update the code. So, is it good to go with suptitle or title?

[chillerobscuro]

Only difference I can see is suptitle is placed with a bit more spacing above the figure, which I think looks nice. Perhaps a core contributor will give a more weighty decision but IMO this looks good to go now.

[miraep8]

Seems like a pretty straightforward change and it works for me. Congrats on making your first contribution @arnavrneo Will merge tomorrow as long as there are no other change requests in the mean time! You are also welcome/encouraged to add yourself to the list of contributors! :)

[arnavrneo]

Thanks!
I've one doubt. For adding myself to the contributors list, do I need to directly edit .all-contributorsrc?

[miraep8]

Hey @arnavrneo - congrats on making your first contribution to sktime!

Apologies I merged this before you were properly added as a contributor, and I am sorry for not answering your questions before! In short - yes - you can add yourself to that document! :) You can either: a) do it yourself in a new PR, b) tack it on to your next PR to sktime or c) I can add you for you! :)

Welcome to sktime again! :) 🎉 🎉 🎉

[arnavrneo]

No worries @miraep8!

Okay, I got it now. I've created #4074. Can you please review it?

Thank you!