[WIP] Demo use for underwater glider data

[castelao]

This is a work in progress so I can get some feedback. The idea here is to show how to use groups, and datatree, for underwater gliders. Other observing platforms could follow the same principle.

I'm proposing something close to this to be adopted by the OceanGliders format standard. Since not many people use groups, some examples help to explain and show how easy it can be with xarray/datatree.

Would it be better as a static page? I'm not suggesting that docs/notebook is the best place for it, but I had to start somewhere.

It might be easier to visualize it here: https://github.com/castelao/datatree/blob/demo-gliders/docs/notebooks/UnderwaterGliders.ipynb

• Closes #xxxx
• Tests added
• Passes pre-commit run --all-files
• New functions/methods are listed in api.rst
• Changes are summarized in docs/source/whats-new.rst

[TomNicholas]

Hi @castelao - this is great to see!

This is a work in progress so I can get some feedback.

From a documentation point of view it would be great if this notebook started with a short high-level overview, e.g, What's an ocean glider? What kind of data does it produce? Why is this a good fit for datatree? Remember other users of datatree might have similar data problems but never done geoscience before, let alone know about ocean glider observations. A conclusion might also be good.

I think the way you have set up your tree object is sensible, but I'm curious whether you see this as an object for performing analyses on (like in this notebook for example) or just as a data storage format?

Would it be better as a static page? I'm not suggesting that docs/notebook is the best place for it, but I had to start somewhere.

I think we just want to add some kind of Gallery section to the docs, with this notebook either linked or as a static page. Keep in mind that long-term this repo will be deprecated in favour of integration upstream in xarray, at which point we will try to find a new home for any gallery examples using datatree.

Also what's going on in the last cell there? Where you use open_datatree but get back a DatasetView? That looks like a bug...

[castelao]

Sure, I'll work on that description.

That is a good question. I guess I was thinking about storage or representation only, but the ultimate goal of a good data model is to allow abstraction in the processing/analysis. So the final goal should be analysis.

Thanks!