Anchor-independent xrfreq search

[aulemahal]

Addressing a Problem?

Searching in a catalog for xrfreq='YS' will not match the entries where that frequency is written as AS-JAN. Same thing for QS vs QS-APR vs QS-JUL vs QS-OCT (and the other 2 groups).

Potential Solution

I see three solutions:

1. In search, expand the requested list with all equivalent xrfreq.
2. Normalize all frequencies that come in the catalog.

Number 2 is my favorite, but the issue is that we don't control all the ways to add entries to the catalog. I guess the normalization could be run upon loading the catalog, as well as in update.

Additional context

xr.infer_freq always returns : AS-JAN, QS-OCT, QS-NOV or QS-DEC. compute_indicators will usually use infer_freq to find the frequency to use in the catalog. Thus, if one passes freq='YS', there's an inconsistency between the output catalog and the input yaml. Only fixing the annual case is easy, but it becomes inelegant when we want to fix the seasonal cases too.

Contribution

• I would be willing/able to open a Pull Request to contribute this feature.