xarray Computation Practice

Part 1

Computation

Filtering or masking values

worksheet? dimensions can still be awkward, even if they aren’t as bad in xarray as they are in numpy.

Getting a bunch of dates with .sel or .isel

Part 2

Look again at the .max() documentation. We see that the dim argument can take either a single string or a sequence of strings. The sequence object we have used most is a List.

Try giving a list as an input to the .max() function to take the max over 2 dimensions of the array.

sst.max(dim=[‘lat’, ‘lon’]) sst.max(dim=[‘lat’, ‘time’]) sst.max(dim=[‘time’, ‘lon’])

• stack/unstack also good for Part 2 homework https://docs.xarray.dev/en/stable/user-guide/reshaping.html#stack-and-unstack

Notice that the conditional doesn’t have to be data from the original dataset - it could be one of its coordinates, or even a totally different dataset of the same shape.

(from the lesson)

two dataset of the same shape, but where the conditional depends on another array. (A Dar group example?)

.rolling()?

https://docs.xarray.dev/en/latest/user-guide/groupby.html#apply using a custom .map() function for aggregation.