[WIP] Add a parameter to enable/disable smoothing on discrete variables in BLV (Issue #2325)

[Patchouli-Kenntnis]

Description

Add a parameter smoothing, default as True, to toggle smoothing on data with integer type.

Checklist

• Follows official PR format
• Includes a sample plot to visually illustrate the changes (only for plot-related functions)
• New features are properly documented (with an example if appropriate)?
• Includes new or updated tests to cover the new feature
• Code style correct (follows pylint and black guidelines)
• Changes are listed in changelog

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📚 Documentation preview 📚: https://arviz--2344.org.readthedocs.build/en/2344/

[Patchouli-Kenntnis]

Since I'm a newcomer here, I'm not sure how to comply with pylint (Your code has been rated at 10.00/10
##[error]Bash exited with code '16'.
Finishing: pylint
) and build the read the docs.
Hope for some generous assistance to help me get into the workflow.

[OriolAbril]

You can see the pylint errors on the CI log (locally you should get something similar); rating isn't really useful, the important thing are the errors you get.

As for docs and failure of the other tests, you are introducing a new argument but it has only been added to matplotlib backend. You need to do the same change to bokeh, otherwise when plot_bpv calls the bokeh backend function it does so with incorrect arguments.

[tomicapretto]

Hi @Patchouli-Kenntnis, thanks for the contribution!

Another two comments from the CI log

************* Module arviz.plots.bpvplot
arviz/plots/bpvplot.py:172:0: C0301: Line too long (116/100) (line-too-long)

That one is saying the line 172 in arviz/plots/bpvplot.py is longer than the maximum length we allow in ArviZ (100). You need to split that into two lines.

************* Module arviz.plots.backends.matplotlib.bpvplot
arviz/plots/backends/matplotlib/bpvplot.py:91:73: C0121: Comparison 'smoothing == True' should be 'smoothing is True' if checking for the singleton value True, or 'bool(smoothing)' if testing for truthiness (singleton-comparison)

does not raise an error per se, but it suggests a more robust practice to test if a value is equal to True (i..e use something is True instead of something == True).

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Let me know if you need help with anything :)