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/1046#issuecomment-254347566,https://api.github.com/repos/pydata/xarray/issues/1046,254347566,MDEyOklzc3VlQ29tbWVudDI1NDM0NzU2Ng==,2443309,2016-10-17T22:00:32Z,2016-10-17T22:00:32Z,MEMBER,"I'm fine with this approach for now. It would be great if we could convince bottleneck to help us out with a keyword argument of some kind.  
","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,182667672
https://github.com/pydata/xarray/issues/1046#issuecomment-253408063,https://api.github.com/repos/pydata/xarray/issues/1046,253408063,MDEyOklzc3VlQ29tbWVudDI1MzQwODA2Mw==,2443309,2016-10-13T03:58:32Z,2016-10-13T03:58:32Z,MEMBER,"We do try to stay consistent with pandas except for the last position. [Here's](https://github.com/pydata/xarray/blob/9cf107b522188e206bd15f4620bc3b55ca30e616/xarray/test/test_dataarray.py#L1549-L1567) the unit test where we verify that behavior.

Using `x=0` from your example in Pandas: 

``` Python
In [1]: import pandas as pd
s
In [2]: data = pd.Series([0, 3, 6])

In [3]: data.rolling(3, center=True, min_periods=1).mean()
Out[3]: 
0    1.5
1    3.0
2    4.5
```

If I remember correctly, and my brain is a bit like mush right now so I could be wrong, `bottleneck` and `pandas` handle this case differently so we had to make a decision.  We choose to use `bottleneck` (for speed) but to do our best to stay consistent with `pandas`.  Back to your example, this time just with `bottleneck`:

``` Python
In [4]: bn.move_mean(data, 3, min_count=1)
Out[4]: array([ 0. ,  1.5,  3. ])
```

So, as you can see, bottleneck does something totally different that wouldn't otherwise work with `center=True` unless we did our little `shift` trick. I'm not really sure the best way to correct for this difference in the last position except to either a) try to push a `center=True` option into `bottleneck` (may not be possible), or b) write a bunch of logic on our end bridge the gap between these two (may be laborious). Of course, I'm open to ideas.
","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,182667672