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/2861#issuecomment-1094070525,https://api.github.com/repos/pydata/xarray/issues/2861,1094070525,IC_kwDOAMm_X85BNjD9,5635139,2022-04-09T15:41:49Z,2022-04-09T15:41:49Z,MEMBER,"Closing, please reopen if still an issue","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,427644858
https://github.com/pydata/xarray/issues/2861#issuecomment-478750808,https://api.github.com/repos/pydata/xarray/issues/2861,478750808,MDEyOklzc3VlQ29tbWVudDQ3ODc1MDgwOA==,1217238,2019-04-01T21:14:56Z,2019-04-01T21:14:56Z,MEMBER,"The usual recommendation is to align all of your separate datasets onto the same grid before combining them. `reindex_like()` and `interp_like()` make this pretty easy, e.g., `proof.interp_like(ref)`.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,427644858
https://github.com/pydata/xarray/issues/2861#issuecomment-478570138,https://api.github.com/repos/pydata/xarray/issues/2861,478570138,MDEyOklzc3VlQ29tbWVudDQ3ODU3MDEzOA==,10050469,2019-04-01T13:03:34Z,2019-04-01T13:03:34Z,MEMBER,"Thanks, I could download them. Can you tell us what the problem with these files is, that we might have to solve in xarray?","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,427644858
https://github.com/pydata/xarray/issues/2861#issuecomment-478546784,https://api.github.com/repos/pydata/xarray/issues/2861,478546784,MDEyOklzc3VlQ29tbWVudDQ3ODU0Njc4NA==,10050469,2019-04-01T11:47:27Z,2019-04-01T11:47:27Z,MEMBER,">  Up to now I never thought about that the 'notnull' method is acting on more than only the data itself

All xarray operations will return xarray objects. And xarray will try to match coordinates wherever possible.

> However, the coordinates are already mathematically identical 

In your example above, they are not. Can you help us to reproduce the error with a [Minimal Complete Verifiable Example](http://matthewrocklin.com/blog/work/2018/02/28/minimal-bug-reports)?","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,427644858
https://github.com/pydata/xarray/issues/2861#issuecomment-478538543,https://api.github.com/repos/pydata/xarray/issues/2861,478538543,MDEyOklzc3VlQ29tbWVudDQ3ODUzODU0Mw==,10050469,2019-04-01T11:17:46Z,2019-04-01T11:19:28Z,MEMBER,"xarray is ""coordinate aware"", i.e. it will try hard to prevent users doing bad things with non matching coordinates (yes, the fact that your `ref` and `proof` are ""not entirely consistent somehow regarding coordinates"" looks like you are doing bad things ;-).

If I understand what you want, this should do the trick:

```python
proof[""WSS""].where(ref[""WSS""].notnull().data)  # use .data here to get back to numpy 
```","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,427644858