id,node_id,number,state,locked,title,user,body,created_at,updated_at,closed_at,merged_at,merge_commit_sha,assignee,milestone,draft,head,base,author_association,auto_merge,repo,url,merged_by
289511996,MDExOlB1bGxSZXF1ZXN0Mjg5NTExOTk2,3033,closed,0,ENH: keepdims=True for xarray reductions,161133,"Add new option `keepdims` to xarray reduce operations, following the behaviour of Numpy.

`keepdims` may be passed to reductions on either Datasets or DataArrays, and will result in the reduced dimensions being still present in the output with size 1.

Coordinates that depend on the reduced dimensions will be removed from the Dataset/DataArray

The name `keepdims` is used here to be consistent with Numpy, `keep_dims` was an alternative name proposed in #2170.

The functionality has only been added to `Variable.reduce()`, `Dataarray.reduce()` and `DataSet.reduce()` to start off with, it is not implemented for `GroupBy`, `Rolling` or `Resample`.

<!-- Feel free to remove check-list items aren't relevant to your change -->

 - [x] Closes #2170
 - [x] Tests added
 - [x] Fully documented, including `whats-new.rst` for all changes and `api.rst` for new API
",2019-06-19T02:04:53Z,2019-06-23T09:18:42Z,2019-06-23T09:18:33Z,2019-06-23T09:18:33Z,ff4198865b42ee2f6f99f3f6f83fed68ef4ffbc7,,,0,413a1e1a878b754e2d249eeebb4074ddaefeeb40,145f25f69078f245313bb8e07b7c6af7509d0de8,CONTRIBUTOR,,13221727,https://github.com/pydata/xarray/pull/3033,