The proper way to do average from Oct to next Sep

[ShihengDuan]

Hi,

I'm trying to use xCDAT to do the water year average (or summation), which is from October in year n, to September in year n+1. This is basically a year average, and in xarray.Dataset.temporal.group_average I see we can customize seasons, but in my case, how should I specify the months from Oct to next Sep? Or should I use some other functions?

Thanks!

[ShihengDuan]

What I do in xarray is to assign a new coordinate called WY, and it equals to time.dt.year+(time.dt.month>9) (Oct, Nov and Dec are in the next water year). And then do a groupby and sum. Finally remove the first and last years if they are incomplete. Is there any smarter way to do it with xcdat?

[jypeter]

@pochedls for custom seasons, we previously used this kind of thing JJAS = cdutil.times.Seasons(‘JJAS’) (see page 14 of cdat_utilities.pdf in #170)

I'm not sure if this is already in one of the existing time related Feature Request.

There is a good chance previous CDAT users need most of the features described in sections 1.1, 1.2 and 2.1 of cdat_utilities.pdf. You can probably ask legacy CDAT users at PCMDI what they think

[pochedls]

@arfriedman and @ShihengDuan – I can see that this would be very useful functionality and I think would be a good feature request. Would one of you be willing to add the feature request? Are either of you interested in putting together code to do this (I think @tomvothecoder might be able to provide guidance)?

@jypeter - there is a discussion thread on New Features / Ideas. I think that would be a good place to engage on prioritizing development going forward. The hope is that the broader community can help to maintain xCDAT and add new functionality, which will help keep xCDAT modern and up-to-date.

[tomvothecoder]

@arfriedman and @ShihengDuan – I can see that this would be very useful functionality and I think would be a good feature request. Would one of you be willing to add the feature request? Are either of you interested in putting together code to do this (I think @tomvothecoder might be able to provide guidance)?

I agree that this sounds useful and is a good feature request. As @pochedls said, I encourage opening up a Feature Request and giving it a shot with a PR! Even submitting a draft PR with an xarray-based implementation can help lay the foundation for an xCDAT API implementation. @xCDAT/core-developers team can jump in the PR to help out too.

Here's xCDAT's contributing guide if there is interest.

[arfriedman]

Thank you @jypeter @tomvothecoder @pochedls.

I can work on putting together a feature request (it will be my first one for any project!).

[pochedls]

@arfriedman – thank you for being willing to put together the feature request - we appreciate the help. Let us know if you have any questions.