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/4463#issuecomment-700226830,https://api.github.com/repos/pydata/xarray/issues/4463,700226830,MDEyOklzc3VlQ29tbWVudDcwMDIyNjgzMA==,1217238,2020-09-28T19:10:55Z,2020-09-28T19:10:55Z,MEMBER,"> I'll note that:
> 
> ```python
> da.sel(y=dy, x=dx, method='nearest')
> ```
> 
> does work, without the need to explicitly pass the shared dimension `t`. This is why I expected that `interp` would work the same.

I think `interp` should work in this case, too!

Let's keep this issue open to track that.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,709272776
https://github.com/pydata/xarray/issues/4463#issuecomment-700080801,https://api.github.com/repos/pydata/xarray/issues/4463,700080801,MDEyOklzc3VlQ29tbWVudDcwMDA4MDgwMQ==,2448579,2020-09-28T15:26:00Z,2020-09-28T15:26:00Z,MEMBER,"> The error message is indeed unclear.

reopening so that we can fix this.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,709272776
https://github.com/pydata/xarray/issues/4463#issuecomment-700076657,https://api.github.com/repos/pydata/xarray/issues/4463,700076657,MDEyOklzc3VlQ29tbWVudDcwMDA3NjY1Nw==,20629530,2020-09-28T15:22:23Z,2020-09-28T15:22:23Z,CONTRIBUTOR,"Oh! I should have thought of this. The error message is indeed unclear... 
I'll close the issue as the problem is solved, but I'll note that:
 ```python3
da.sel(y=dy, x=dx, method='nearest')
```
does work, without the need to explicitly pass the shared dimension `t`.  This is why I expected that `interp` would work the same.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,709272776
https://github.com/pydata/xarray/issues/4463#issuecomment-699435286,https://api.github.com/repos/pydata/xarray/issues/4463,699435286,MDEyOklzc3VlQ29tbWVudDY5OTQzNTI4Ng==,1217238,2020-09-26T06:05:22Z,2020-09-26T06:05:22Z,MEMBER,"I think this gives the correct result?
```
>>> da.interp(t=da['t'], y=dy, x=dx, method='linear')
<xarray.DataArray (t: 2, u: 2)>
array([[2., 3.],
       [2., 3.]])
Coordinates:
  * t        (t) int64 10 12
    y        (u) float64 1.5 2.5
    x        (t, u) float64 1.5 1.5 1.5 1.5
  * u        (u) int64 45 55
```

My general thought is that if an axis (like `t` in this case) is omitted, then should be equivalent to indexing with the existing coordinate. That is how normal indexing in xarray worked, so interpolation should work the same.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,709272776
https://github.com/pydata/xarray/issues/4463#issuecomment-699169927,https://api.github.com/repos/pydata/xarray/issues/4463,699169927,MDEyOklzc3VlQ29tbWVudDY5OTE2OTkyNw==,6815844,2020-09-25T21:42:40Z,2020-09-25T21:42:40Z,MEMBER,"Hi @aulemahal 

I think you want to interpolate along `t`as well as `x`, and `y`.
If so, you can do 

```python
In [8]: da.interp(t=dx['t'], y=dy, x=dx, method='linear')                       
Out[8]: 
<xarray.DataArray (t: 2, u: 2)>
array([[2., 3.],
       [2., 3.]])
Coordinates:
  * t        (t) int64 10 12
    y        (u) float64 1.5 2.5
    x        (t, u) float64 1.5 1.5 1.5 1.5
  * u        (u) int64 45 55
```

If not, this fails as `dx['t']` and `da['t']` do not match each other.
The error message can be improved.
A contribution is welcome ;)","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,709272776