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/4995#issuecomment-791145448,https://api.github.com/repos/pydata/xarray/issues/4995,791145448,MDEyOklzc3VlQ29tbWVudDc5MTE0NTQ0OA==,2448579,2021-03-05T04:32:29Z,2021-03-05T04:32:29Z,MEMBER,"Actually does `reindex` do what you want, the returned coordinate labels will be what you provide.

```
>>> ds.reindex(lat=[5,15,40], method=""nearest"", tolerance=5, fill_value=-999)
<xarray.DataArray (lat: 2)>
array([1, 2, -999])
Coordinates:
  * lat      (lat) int64 5 15 40
```","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,822320976
https://github.com/pydata/xarray/issues/4995#issuecomment-791021835,https://api.github.com/repos/pydata/xarray/issues/4995,791021835,MDEyOklzc3VlQ29tbWVudDc5MTAyMTgzNQ==,2448579,2021-03-04T23:16:00Z,2021-03-04T23:16:00Z,MEMBER,"> in using a fill_value is that the indexing has to modify the data ( insert e.g. -999) and also 'invent' a new coordinate point ( here 40). 

This seems totally doable though.

> One fill_value might not fit to all data arrays 

In quite a few functions, fill_value can be a dict mapping variable name to a value so this is workable.

Let's see what others think.","{""total_count"": 2, ""+1"": 2, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,822320976
https://github.com/pydata/xarray/issues/4995#issuecomment-790878651,https://api.github.com/repos/pydata/xarray/issues/4995,790878651,MDEyOklzc3VlQ29tbWVudDc5MDg3ODY1MQ==,2448579,2021-03-04T19:40:29Z,2021-03-04T19:40:29Z,MEMBER,"```
>>> ds.sel(lat=[5,15,40], method=""nearest"", tolerance=5)
<xarray.DataArray (lat: 2)>
array([1, 2])
Coordinates:
  * lat      (lat) int64 10 20
```

This is a very surprising result, you've asked for values at three points but received two back. 

The following (specifying `fill_value`) seems like better behaviour to me but how do you choose the coordinate label (here I picked `40` since that was provided to `sel`)
```
>>> ds.sel(lat=[5,15,40], method=""nearest"", tolerance=5, fill_value=-999)
<xarray.DataArray (lat: 2)>
array([1, 2, -999])
Coordinates:
  * lat      (lat) int64 10 20 40
```","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,822320976