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/pull/1962#issuecomment-371680749,https://api.github.com/repos/pydata/xarray/issues/1962,371680749,MDEyOklzc3VlQ29tbWVudDM3MTY4MDc0OQ==,1217238,2018-03-09T01:16:42Z,2018-03-09T01:16:42Z,MEMBER,"If you try to put a pint array into xarray.DataArray right now, I'm pretty sure it will get cast into a NumPy array.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,302153432
https://github.com/pydata/xarray/pull/1962#issuecomment-371658417,https://api.github.com/repos/pydata/xarray/issues/1962,371658417,MDEyOklzc3VlQ29tbWVudDM3MTY1ODQxNw==,1217238,2018-03-08T23:17:52Z,2018-03-08T23:17:52Z,MEMBER,"@dopplershift  see https://github.com/pydata/xarray/issues/1938. Units should be able to make use of the same machinery as sparse arrays (`__array_ufunc__` and multipledispatch), but xarray itself implementing `__array_ufunc__` is not particularly useful, because you still can't put your own custom array types inside xarray objects.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,302153432
https://github.com/pydata/xarray/pull/1962#issuecomment-371355899,https://api.github.com/repos/pydata/xarray/issues/1962,371355899,MDEyOklzc3VlQ29tbWVudDM3MTM1NTg5OQ==,1217238,2018-03-08T02:20:21Z,2018-03-08T02:20:21Z,MEMBER,"One potential edge case is if someone directly calls a ufunc reduce method, e.g., `np.add.reduce`. Previously, this would cast the xarray object to a numpy array, but now it will raise an error.

Example:
```
# current xarray
In [3]: np.add.reduce(xr.DataArray([1]))
Out[3]: 1

# with this pull request
In [3]: np.add.reduce(xr.DataArray(0))
NotImplementedError: reduce method for ufunc <ufunc 'add'> is not implemented on xarray objects, which currently only support the __call__ method.
```

Note that the more commonly used aliases for these reduce methods, e.g., `np.sum()` will continue to work since they check for `sum()` method on their argument.

There are also a few other [ufunc methods](https://docs.scipy.org/doc/numpy/reference/ufuncs.html#methods) that get used occasionally.

I think I'm OK breaking these because usage is so rare (and the work-around of casting to numpy arrays is so easy) but this should probably be noted in the release notes.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,302153432