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/pull/1412#issuecomment-303984274,https://api.github.com/repos/pydata/xarray/issues/1412,303984274,MDEyOklzc3VlQ29tbWVudDMwMzk4NDI3NA==,6815844,2017-05-25T11:04:55Z,2017-05-25T11:04:55Z,MEMBER,Replaced by a new PR #1426 .,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,229370997
https://github.com/pydata/xarray/pull/1412#issuecomment-302919742,https://api.github.com/repos/pydata/xarray/issues/1412,302919742,MDEyOklzc3VlQ29tbWVudDMwMjkxOTc0Mg==,6815844,2017-05-21T07:13:37Z,2017-05-21T07:13:37Z,MEMBER,"@benbovy
Thanks for the valuable comments.
Actually I can not fully imagine how the actual implementation looks like currently,
but I also think the virtual variable access needs some tricks.
This is an essential functionality of the MultiIndex-coordinate,
I will try to investigate it.
Thanks.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,229370997
https://github.com/pydata/xarray/pull/1412#issuecomment-302693433,https://api.github.com/repos/pydata/xarray/issues/1412,302693433,MDEyOklzc3VlQ29tbWVudDMwMjY5MzQzMw==,6815844,2017-05-19T12:47:28Z,2017-05-19T12:47:28Z,MEMBER,"I also agree. It seems too magical.
But I slightly changed my mind.
I notice what I really want to have is not particular scalar coordinate in MultiIndex,
but 'unified' interface between normal `Vraiable` and `MultiIndex`.
The current structure is illustrated as follows,
The `MultiIndex` has different characteristics from normal `Variable`.
For example, if we do `ds.sel(x=2)`, it makes a scalar coordinate and normal Variable.
The backward process might be `.expand_dims().stack()`.
This is different from normal `Variable` behavior.
And because of it, MultiIndex should be treated in special way in every place.
(Deprecating the automatic-renaming does not change things so much.)
I am wondering if we could have the following class structure things become simpler
In this picture, MultiIndex can have `scalar` as its level and `.isel()` produces it.
This process can be traced backward by `.expand_dims()` or `.concat()` as in normal `Variable`.
I understand it is different from `pandas.MultiIndex` structure, and we need to expand our wrapper extensively if we decide to realize it (as written in red).
But I feel this symmetric structure could make it easy to expand `MultiIndex` functionalities in future.
Any thoughts are welcome.
(Should move discussion to another issue?)","{""total_count"": 1, ""+1"": 1, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,229370997
https://github.com/pydata/xarray/pull/1412#issuecomment-302299557,https://api.github.com/repos/pydata/xarray/issues/1412,302299557,MDEyOklzc3VlQ29tbWVudDMwMjI5OTU1Nw==,6815844,2017-05-18T04:48:29Z,2017-05-18T04:48:29Z,MEMBER,"@shoyer
Thanks for the comment.
> It breaks an important invariant, which is that indexing a Variable returns another Variable.
I totally agree with you.
In the last commit, I moved the unpacking functionality into `Dataset`, and restored the modification in `Variable` class I made.
I think the current is cleaner than my previous one, but I'm not yet comfortable with it.
There are a lot of functions or `if`-statements related to `MultiIndex` in different places.
I guess they should be bundled in one place.
Adding functions is easy but simplifying them are difficult...
If anyone show a direction, I will try the improvement.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,229370997