DRAFT: Support ccrs.Geodetic source projection, add Polygon plot to Grid

[philipc2]

Closes #1230

Overview

• Adds support for using Cartopy's Geodetic projection as a source projection, allowing for better visualization of grids on the surface of a sphere and for handling splitting along the dateline: shapes crossing the dateline are not plotted correctly holoviz/geoviews#107
• Using the Geodetic projection is especially useful for coarser grids where the distortion is more noticeable, and over the poles
• Implements a Grid.plot.polygons() method that plots shaded polygons using the index of each face.

Examples

No Source Projection

Geodetic Source Projection

[Copilot]

Pull Request Overview

This PR adds support for using Cartopy's Geodetic projection as a source CRS and implements a new polygons plotting method to shade grid faces by their index. Key changes include:

• The introduction of the check_crs helper function in utils.py to handle CRS adjustments.
• Modifications to the edges and mesh methods and the addition of a new polygons method in accessor.py.
• Updates to the test suite (test_plot.py) to cover these new functionalities.

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
uxarray/plot/utils.py	Added check_crs function for CRS handling
uxarray/plot/accessor.py	Updated edges, mesh; added polygons method with CRS adjustments and raster settings
test/test_plot.py	Extended tests to cover new polygons plotting and Geodetic projection usage

[erogluorhan]

This is great! Some thoughts on a few things though:

• The name grid.plot.polygons() can potentially be confused with our polygons() visualizations that plot data values based polygons instead.
  • How about renaming it from polygons to something else?
    • Just an idea: This is only for topology diagnostics purposes, right? Maybe something to emphasize this aspect better, which'd also help avoid confusions with the other polygons? e.g. grid.plot.shade_faces() , etc?
• In addition to renaming, if still needed, maybe also consider either adding a bigger emphasis on the purpose of this plotting function into the docstrings or displaying a warning message when this is called
• Values in the color bars in both cases of fill argument for this function do not make much sense, e.g. face indices being float, or those float values around 1 when it is polygons.

[philipc2]

Closing this, as the ccrs.GeoDetic() projection is already supported. Will reopen an issue and PR with changes to documentation and/or usage if needed in the future.