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/1731#issuecomment-346160627,https://api.github.com/repos/pydata/xarray/issues/1731,346160627,MDEyOklzc3VlQ29tbWVudDM0NjE2MDYyNw==,1217238,2017-11-21T21:05:18Z,2017-11-21T21:05:18Z,MEMBER,"> nanrankdata only support numeric types, how about wrapping rankdata with a keyword option ?

We already do dispatching to appropriate functions based on the dtype for aggregations:
https://github.com/pydata/xarray/blob/9d09c1659741dafb1fadeed49c81f9e90a548b07/xarray/core/duck_array_ops.py#L174
(Yes, this is a bit of a mess)

Since `NaN` has a consistent sorting position in NumPy/bottleneck (it sorts to the end), I would suggest including a `skipna` keyword argument, like one we use for aggregation functions. Alternatively, we could use `na_option : {‘keep’, ‘top’, ‘bottom’}` [like pandas](https://pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.rank.html).

> There's also a push push method similar to pandas ffill which would be nice.

@jhamman is already working on `ffill`/`bfill` in https://github.com/pydata/xarray/pull/1640","{""total_count"": 1, ""+1"": 1, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,275461273