html_url,issue_url,id,node_id,user,created_at,updated_at,author_association,body,reactions,performed_via_github_app,issue
https://github.com/pydata/xarray/issues/1978#issuecomment-371990150,https://api.github.com/repos/pydata/xarray/issues/1978,371990150,MDEyOklzc3VlQ29tbWVudDM3MTk5MDE1MA==,5635139,2018-03-10T01:23:06Z,2018-03-10T01:23:06Z,MEMBER,"> this looks eerily similar to #1837

🤦‍♂️  I think my memory is getting worse every day! I glanced at this myself back in Jan.

Closing!","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,304021813
https://github.com/pydata/xarray/issues/1978#issuecomment-371989690,https://api.github.com/repos/pydata/xarray/issues/1978,371989690,MDEyOklzc3VlQ29tbWVudDM3MTk4OTY5MA==,6815844,2018-03-10T01:18:11Z,2018-03-10T01:18:11Z,MEMBER,"Yes. 
```python
In [7]: da.rolling(date=3).construct('rolling_date')
Out[7]: 
<xarray.DataArray (item: 2, date: 6, rolling_date: 3)>
array([[[nan, nan,  0.],
        [nan,  0.,  1.],
        [ 0.,  1.,  2.],
        [ 1.,  2.,  3.],
        [ 2.,  3.,  4.],
        [ 3.,  4.,  5.]],

       [[nan, nan,  6.],
        [nan,  6.,  7.],
        [ 6.,  7.,  8.],
        [ 7.,  8.,  9.],
        [ 8.,  9., 10.],
        [ 9., 10., 11.]]])
Dimensions without coordinates: item, date, rolling_date
```
does the similar thing (`rolling_window` in your example).

FYI, using `sum` without skipna option for such a *strided* DataArray (in your `test_rolling_window_values`) is not a good idea.
We internally use `np.nansum` and this copies the entire array once. It throws away the advantage of the strided trick.
`sum(skipna=False)` is memory efficient.
","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,304021813
https://github.com/pydata/xarray/issues/1978#issuecomment-371986534,https://api.github.com/repos/pydata/xarray/issues/1978,371986534,MDEyOklzc3VlQ29tbWVudDM3MTk4NjUzNA==,1217238,2018-03-10T00:51:42Z,2018-03-10T00:51:42Z,MEMBER,"This is exactly what @fujiisoup just implemented in #1837.

It's a nice trick. If the window is large, it's not quite as fast using a clever algorithm for rolling sums like bottleneck, but it still gives something like a 100x performance boost over the naive loop we used to use.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,304021813
https://github.com/pydata/xarray/issues/1978#issuecomment-371985627,https://api.github.com/repos/pydata/xarray/issues/1978,371985627,MDEyOklzc3VlQ29tbWVudDM3MTk4NTYyNw==,2443309,2018-03-10T00:45:03Z,2018-03-10T00:45:03Z,MEMBER,I'll let @fujiisoup / @shoyer confirm but this looks eerily similar to #1837.,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,304021813