BUG: Rolling on Dataset

This looks like it’s available with dir / tab complete, but actually isn’t:

In [13]: xr.DataArray(np.random.rand(10,3)).to_dataset('dim_1').rolling
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-13-438d3638a0d0> in <module>()
----> 1 xr.DataArray(np.random.rand(10,3)).to_dataset('dim_1').rolling

/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/xarray/core/common.py in __getattr__(self, name)
    135                     return source[name]
    136         raise AttributeError("%r object has no attribute %r" %
--> 137                              (type(self).__name__, name))
    138 
    139     def __setattr__(self, name, value):

AttributeError: 'Dataset' object has no attribute 'rolling'

I think this could be easy to implement as an .apply operation? (indeed, that could be a reasonable path for a whole host of operations - i.e. try and apply them to each array in the ds?)

Also, as a very narrow point, I’m not sure why .rolling_cls is public? Probably should be private?

Finally, the Rolling implementation is pretty sweet. I’ve been getting my hands dirty in the pandas one recently, and that we can have something as well featured as that with so few lines of code 👍

[fmaussion]

This just happened to me too:

In [1]: import xarray as xr
In [2]: ds = xr.open_dataset('ERA-Int-Monthly-UVSLP.nc')
In [3]: ds = ds.rolling()
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-3-16ff572cfc35> in <module>()
----> 1 ds = ds.rolling()

/home/mowglie/Documents/git/xarray/xarray/core/common.py in rolling(self, min_periods, center, **windows)
    507         """
    508 
--> 509         return self.rolling_cls(self, min_periods=min_periods,
    510                                 center=center, **windows)
    511 

/home/mowglie/Documents/git/xarray/xarray/core/common.py in __getattr__(self, name)
    224                     return source[name]
    225         raise AttributeError("%r object has no attribute %r" %
--> 226                              (type(self).__name__, name))
    227 
    228     def __setattr__(self, name, value):

AttributeError: 'Dataset' object has no attribute 'rolling_cls'

[max-sixty]

Did this ever get fixed?

Not fixed yet, but PRs welcome