Tom White

I tried some of the suggestions from the SO page, but then I get `RuntimeWarning: coroutine 'async_execute_dag' was never awaited`, and can't see an obvious way to avoid it. It...

Here's a jupyter notebook: https://github.com/tomwhite/cubed/blob/f5ece5b068db014f828bf6f3afcf6b05280af52a/examples/pangeo-tem.ipynb There are a couple of pieces missing. The first is fairly minor, and is that `mean` doesn't work yet with NaNs, so I've added `skipna=False`...

Thanks @dcherian. For intermediates, Cubed uses structured arrays (e.g. [`mean`](https://github.com/tomwhite/cubed/blob/cc4bc8d92346546446a766a920432b848363f91d/cubed/array_api/statistical_functions.py#L18-L36)), which seems similar to Flox. > That said, for this particular problem I could write the groupby as an efficient...

I've added integer array indexing (and `take`) to Cubed now (0b59b3241d06b2e57ba4011c538def5e245d7a5d), which should help for group by. I've update the example notebook at https://github.com/tomwhite/cubed/blob/5eb5f23c25c37ec8634eb35a71711f4eaaffd643/examples/pangeo-tem.ipynb (this needed a few xarray changes)....

> In fact, "cubed" is not available on pypi (I used [this package](https://pypi.org/project/check-availability/) to check quickly). [cubed on PyPi](https://pypi.org/project/cubed) is this project! 😄 Naming is hard! Finding a name that...

This looks very useful - thanks @TomNicholas!

The implementation described at https://en.wikipedia.org/wiki/Algorithms_for_calculating_variance#Parallel_algorithm looks like the one to use here.

I think this is happening because [Xarray's default groupby strategy](https://flox.readthedocs.io/en/latest/implementation.html#background-xarray-s-current-groupby-strategy) indexes out each group as a new array and then applies the operation (`mean` in this case) to each array....

> ```python > ValueError: Array must have regular chunks > ``` It would be useful to see what the irregular chunking actually is so we can see how it came...

> Zarr doesn't yet support irregular yet chunks right? Seems to be [tracked in ZEP003](https://github.com/orgs/zarr-developers/discussions/52). So does that mean `blockwise` is a no-go for groupby in cubed for now? That's...