Add planar horizontal viz

[cbegeman]

This PR ports the plot_horiz_field function from compass/ocean/tests/isomip_plus/viz/__init__.py into a shared viz folder. There are relatively minor changes related to this being used outside plot_horiz_series and making the figure size match the domain aspect ratio. To demonstrate its functionality, it is added to the initial_state step of the baroclinic_channel test case.

Two functions are also needed:

• _remove_boundary_edges_from_mask makes sure that the periodic edges are not included (those polygons would span from one edge of the periodic domain to the other and obscure the other polygons)
• _compute_cell_patches is a direct port from compass/ocean/tests/isomip_plus/viz/__init__.py
• _compute_edge_patches is a new function analogous to _compute_cell_patches

Checklist

• Developer's Guide has been updated
• API documentation in the Developer's Guide (api.md) has any new or modified class, method and/or functions listed
• Documentation has been built locally and changes look as expected
• Testing comment in the PR documents testing used to verify the changes

[cbegeman]

Testing

I have run the baroclinic_channel/10km/default test case on compy.

Initial temperature

Final normalVelocity (when test is run for 1 day)

[cbegeman]

@xylar You can review the scripts now if you like. I'm sure there are ways that we could make them better, but I think this is a reasonable level of effort given that these are temporary files for the hackathon. Let me know if you feel differently. I haven't added the documentation yet, but will.

[xylar]

Yep, this is fantastic! A few more tiny changes.

[xylar]

A few more. Sorry these keep coming in in small batches. I just keep thinking I'm done and then playing with the code a bit more.

[cbegeman]

@xylar I added some text to the developer's guide. I'm not sure whether/how to update the api though when the function is located in polaris/viz/__init__.py. It doesn't appear to recognize polaris.viz as a module

[xylar]

Great! The API needs to be added in an appropriate spot (maybe alphabetically somehow) here https://github.com/E3SM-Project/polaris/blob/main/docs/developers_guide/api.md

[xylar]

I should go after validate and before yaml here:
https://github.com/E3SM-Project/polaris/blob/main/docs/developers_guide/api.md?plain=1#L328-L355
Maybe you can fix the second validate, which should be yaml while you're there?

[cbegeman]

@xylar Thanks! That did the trick

[cbegeman]

@xylar Now that the docs are done it is ready to be merged, unless you have more feedback.

[xylar]

Looks great! Go ahead and merge with the green button!

[xylar]

@cbegeman, I missed this in my review but it looks like the 2 images you refer to in the docs didn't actually get added. Could you make a quick PR to add them when you get a chance?

[xylar]

Never mind, I just added them in #38. I used the 2 images above. I hope that's what you had in mind.