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/3224#issuecomment-523155674,https://api.github.com/repos/pydata/xarray/issues/3224,523155674,MDEyOklzc3VlQ29tbWVudDUyMzE1NTY3NA==,1217238,2019-08-20T19:13:16Z,2019-08-20T19:13:16Z,MEMBER,"I appreciate how this could be convenient, but I am concerned about adding more complexity to xarray's merge code, which is already pretty complex and hard to maintain. My refactor in https://github.com/pydata/xarray/pull/3234 is the first time that code has been touched in quite a while and I don't think anyone (other than myself) has made contributions to that part of xarray.

To solve your use-case, what about either:
1. Converting `observations` into a MultiIndex over `individual` and `subtissue`, or
2. Creating separate `individual`/`subtissue` dimensions and storing the data the data in the form of a sparse array

Then you could do this sort of data munging with normal indexing/alignment/merging, e.g.,
```python
tissue_1 = ds.sel(subtissue=""Whole_Blood"").rename({k: k + ':1' for k in ds})
tissue_2 = ds.sel(subtissue=""Adipose_Subcutaneous"").rename({k: k + ':2' for k in ds})
merged = tissue_1.merge(tissue_2)  # would have dimensions [gene, individual]
```","{""total_count"": 1, ""+1"": 1, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,481838855