Plots/Refactor balloon plot (ax, colorbar)

[hoyer-a]

Changes proposed in this pull request:

• return colorbar for balloon plot
• allow input of 2 axes as tuple, list or array
• plot colorbar on second axis

Discussion

• plotting the colorbar on an axis only works for projections 'polar' and 'rectilinear' and only makes sense for 'rectilinear'. Therefore i would force the second passed ax to be 'rectilinear' and throw an error otherwise.

The if function.__name__ in ... cases in the tests can be removed once all plot functions are adjusted.

Depends on #214

[sikersten]

Thank you, very nice!

[ahms5]

Nice, thanks, just one question out the retrun of ax.

[ahms5]

Thanks looks good, just have a minor optional suggesstion, approved anyways.

[ahms5]

very optional: could be a dedicated test for testing the outputs for ballon plots

[hoyer-a]

I thought about that too, but it would be very redundant to what is already tested.

[mberz]

The if function.__name__ in ... cases in the tests can be removed once all plot functions are adjusted.

Could you please elaborate what you mean by this? If this information needs to survive beyond this PR, please open an issue.

[hoyer-a]

To have the tests run without failing i added cases for the refactored functions with new ax and colorbar returns.
Since i am collection in a branch (plot/ax_colorbar_refactor) until all plot functions have been adjusted, i would create a PR from this branch and put it in a todo.

e.g.:

@pytest.mark.parametrize(("function", "projection"), [
    (sp.plot.balloon, '3d'),
    (sp.plot.balloon_wireframe, '3d'),
     ...
    ])
def test_data_plots_projection_input_and_return(function, projection):
    ...

    if function.__name__ in ['balloon']:
        ax_out = ax_out[0]
    # check if the returned axis has the correct projection

[hoyer-a]

Also #214 should be merged first

[mberz]

Also #214 should be merged first

I've updated the description to include this information.