Functions for detector splits

[chervias]

Functions for detector splits. First we start with a relative detector function, then we can add an absolute splits, etc.

[msilvafe]

Just a few comments to make this a bit more compatible with the structure used in other functions and to be more compatible with the structure of the preprocess module. Perhaps @kmharrington or @mhasself has opinions about whether this should go in a new obs_ops module or if it should go in tod_ops.flags I suppose since these are returning boolean masks that are shape dets not RangesMatrices shape dets x samps it may make more sense to delineate that way and have dets type masks live here in obs_ops

[msilvafe]

Add an argument called wrap which defaults to None and if None or False it does not wrap the flags into the input axis manager. If wrap is a True it wraps into some default field name det_flags and if wrap is a string then it wraps the flags into that field name.

[msilvafe]

Create a new axis manager called det_flags or dflag_aman and only wrap it if the wrap argument is not False/None.

[msilvafe]

Also return the det_flags or dflag_aman axis manager and only wrap it into aman if wrap is not None/False.

[chervias]

If I try to run again the function and a wrap is attempted for a field that already exists this will fail, but I think it should overwrite.

[msilvafe]

This looks good, the issue you brough up about overwriting I addressed in PR #824 and I don't think should be tied to this PR.

Actually before merge can you add some docs into /docs perhaps add an obs_ops.rst and describe the purpose of the splits and how to use there?

[msilvafe]

This can just be if not(wrap) if wrap is None or False then not(wrap) will be True.

[msilvafe]

Just return fm don't need to return aman

[chervias]

done. So for example if I wrap a left/right split, and later I decide I actually want a left/right and a upper/lower split, when I run this function again it will fail. I think it should by default overwrite. Do you agree? We can add that later once there is a clean way of overwriting fields to a aman

[chervias]

sorry I didn't see docs stuff, I'll do it before merging

[msilvafe]

done. So for example if I wrap a left/right split, and later I decide I actually want a left/right and a upper/lower split, when I run this function again it will fail. I think it should by default overwrite. Do you agree? We can add that later once there is a clean way of overwriting fields to a aman

Yes for now outside of this function you will need to run aman.move('det_flags', None) and can move overwrite in here if needed when that PR is merged.

[msilvafe]

Looks good, just a couple comments but won't make them blocking. So you know, to test the docs build I create a virtual environment, install all of the dependencies, and then build the html.

$ virtualenv test
$ source test/bin/activate
$ pip install -r docs/requirements.txt
$ cd docs
$ make html

Then I just open the html files written to sotodlib/docs/_build/html and inspect the relevant pages to make sure all the formatting looks reasonable. When building this way Warnings don't get elevated to Errors like they do in the GitHub CI tests (which was what you pinged me about).

[msilvafe]

You can delete these lines, the line above that calls :members: means that it will render the docstrings for all of the functions within the obs_ops.splits module so currently you're duplicating the docstring for that fn in two places:

[msilvafe]

I think that if det_flags doesn't exist in aman already this will fail so may need a check like:

if name in aman._fields:
    aman.move(name, None)

[msilvafe]

Looks good, thanks Carlos.