non-dimension coordinates

[Beforerr]

In Python Xarray, we can have non-dimension coordinates that contain coordinate data, but are not a dimension coordinate (see https://docs.xarray.dev/en/stable/user-guide/data-structures.html#coordinates) .

I'm just wondering if there is any similar support for this in the ecosystem. Actually this idea is kinda of useful for working with multidimensional coordinates.

[rafaqz]

Have been thinking about something like this in Rasters as CF standards allow having multiple lookup coordinates for a single dimension. Is that what you mean?

My current idea is to allow dimensions/lookup nesting, so a dimension can have alternative names and associated lookups. Then e.g. X=At(100) may be in metres but you can use Lon=At(100) and that's degrees. The Lon dimensions would be a field of the X dimensions lookup array, and used as a fallback when Lon is not found in the normal top level Tuple of dims.

[Beforerr]

I am more thinking about multidimensional coordinates. You can check the draft PR here #1086 . I am not sure it's a good idea to put the type in this package or just split it into a new package.

[asinghvi17]

Ah so you want to mix the dimensions of the dimensions and coordinates? So X and Y can be 1D regular but there is also a 2D lon and 2D lat associated.

[Beforerr]

Right. Something Like that, I think it would be beneficial to differentiate between coordinate and dimension.

[rafaqz]

Try to avoid starting a new package

This functionality is planned for our overhaul of CF standards in Rasters.jl. DD lookups will be able to represent any CF object which includes single and multidimensional co-ordinate variables. Without changing the dims interface ;)

But it will be a few months.

[Beforerr]

Thanks for clarifying! That sounds great. A few months is no problem—I can work around it in the meantime. Looking forward to the overhaul and the DD lookups supporting full CF objects.

[rafaqz]

Great! can I ping you for reviews?

[Beforerr]

Absolutely, one is glad to be of service

[JamesWrigley]

I would also like this 👀 Happy to test it out when ready.