Add attributes to generated variables.

[dcherian]

xref #22

[benbovy]

This looks like a nice feature to have. I'm wondering, however, do we want to be opinionated and always add those CF attributes? Or should it rather be optional and provide a RasterIndex option or something like xproj's write_crs_info()? Or even find a way to handle that via xproj (e.g., add a hook in xproj.ProjIndexMixin)?

[dcherian]

I'm wondering, however, do we want to be opinionated and always add those CF attributes?

I like opinionated, there's no real downside to it.

even find a way to handle that via xproj (e.g., add a hook in xproj.ProjIndexMixin)?

This would be quite nice, and would remove one reason RasterIndex needs to track CRS. But how?

[benbovy]

would remove one reason RasterIndex needs to track CRS

I was rather thinking about writing those attributes via calling ds.proj.write_crs_info(), which would still need RasterIndex to track CRS (i.e., be "CRS-aware" from xproj's point of view).

[dcherian]

but the write_crs_info hook could provide the CRS to the index? Does xproj handle multiple CRS in the same Dataset though?