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/1378#issuecomment-367152237,https://api.github.com/repos/pydata/xarray/issues/1378,367152237,MDEyOklzc3VlQ29tbWVudDM2NzE1MjIzNw==,2443309,2018-02-20T23:03:54Z,2018-02-20T23:03:54Z,MEMBER,"@gerritholl - rereading this issue, I don't think we're particularly opposed to supporting duplicate dimensions. We do know there are things that don't work right now and that we don't have test coverage for operations that use duplicate dimensions. 

This is marked as a `help wanted` issue and I suspect that if someone like yourself, who has a use case for this functionality, were to want to work on this issue, we'd be happy to see it move forward. ","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,222676855
https://github.com/pydata/xarray/issues/1378#issuecomment-295791392,https://api.github.com/repos/pydata/xarray/issues/1378,295791392,MDEyOklzc3VlQ29tbWVudDI5NTc5MTM5Mg==,1217238,2017-04-20T15:59:40Z,2017-04-20T15:59:40Z,MEMBER,"> I cannot see a use case in which repeated dims actually make sense.

Agreed. I would have disallowed them entirely, but sometimes it's useful to allow loading variables with duplicate dimensions, even if the only valid operation you can do is de-duplicate them.

Every routine that looks up dimensions by name should go through the [`get_axis_num` method](https://github.com/pydata/xarray/blob/ab4ffee919d4abe9f6c0cf6399a5827c38b9eb5d/xarray/core/common.py#L112). That would be a good place to add a check for uniqueness.","{""total_count"": 1, ""+1"": 1, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,222676855
https://github.com/pydata/xarray/issues/1378#issuecomment-295710929,https://api.github.com/repos/pydata/xarray/issues/1378,295710929,MDEyOklzc3VlQ29tbWVudDI5NTcxMDkyOQ==,10050469,2017-04-20T12:11:18Z,2017-04-20T12:11:18Z,MEMBER,"> In my case this situation originates from h5 files which indeed contains repeated dimensions 

Yes this happened to me too. First thing I did is converting the files to proper netcdf datasets...","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,222676855
https://github.com/pydata/xarray/issues/1378#issuecomment-295614924,https://api.github.com/repos/pydata/xarray/issues/1378,295614924,MDEyOklzc3VlQ29tbWVudDI5NTYxNDkyNA==,10050469,2017-04-20T07:47:18Z,2017-04-20T07:47:18Z,MEMBER,"I guess it would be good to document the expected behaviour with repeated dims somewhere? I.e. what should happen when doing:
```
a = xr.DataArray(eye(3), dims=['dim0', 'dim0'])
a.mean(dim='dim0')
```
?
","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,222676855
https://github.com/pydata/xarray/issues/1378#issuecomment-295431292,https://api.github.com/repos/pydata/xarray/issues/1378,295431292,MDEyOklzc3VlQ29tbWVudDI5NTQzMTI5Mg==,1217238,2017-04-19T20:39:33Z,2017-04-19T20:40:08Z,MEMBER,"Indeed, we don't have very good test coverage for operations with repeated dimensions. Fixes would certainly be appreciated, though they might be somewhat tricky. Even failing loudly with `ValueError: repeated dimensions not yet supported` would be an improvement over the current state.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,222676855
https://github.com/pydata/xarray/issues/1378#issuecomment-295192317,https://api.github.com/repos/pydata/xarray/issues/1378,295192317,MDEyOklzc3VlQ29tbWVudDI5NTE5MjMxNw==,10050469,2017-04-19T09:46:37Z,2017-04-19T09:46:37Z,MEMBER,"Yes, also happening on latest master.

I suspect there are several other things which won't work properly (or at least unexpectedly) when having repeated dims...","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,222676855