issues: 1189140909

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id node_id number title user state locked assignee milestone comments created_at updated_at closed_at author_association active_lock_reason draft pull_request body reactions performed_via_github_app state_reason repo type
1189140909 I_kwDOAMm_X85G4Nmt 6434 concat along dim with mix of scalar coordinate and array coordinates is not right 2448579 closed 0     3 2022-04-01T02:29:16Z 2022-04-06T01:19:47Z 2022-04-06T01:19:47Z MEMBER      

What happened?

Really hard to describe in words =)

concat = xr.concat([da.isel(time=0), da.isel(time=[1])], dim="time") xr.align(concat, da, dim="time")

fails when concat and da should be identical. This is causing failures in cf-xarray:https://github.com/xarray-contrib/cf-xarray/issues/319

cc @benbovy

What did you expect to happen?

No response

Minimal Complete Verifiable Example

```Python import numpy as np import xarray as xr

time = xr.DataArray( np.array( ["2013-01-01T00:00:00.000000000", "2013-01-01T06:00:00.000000000"], dtype="datetime64[ns]", ), dims="time", name="time", )

da = time concat = xr.concat([da.isel(time=0), da.isel(time=[1])], dim="time") xr.align(da, concat, join="exact") # works

da = xr.DataArray(np.ones(time.shape), dims="time", coords={"time": time}) concat = xr.concat([da.isel(time=0), da.isel(time=[1])], dim="time") xr.align(da, concat, join="exact") ```

Relevant log output

```

ValueError Traceback (most recent call last) Input In [27], in <module> 17 da = xr.DataArray(np.ones(time.shape), dims="time", coords={"time": time}) 18 concat = xr.concat([da.isel(time=0), da.isel(time=[1])], dim="time") ---> 19 xr.align(da, concat, join="exact")

File ~/work/python/xarray/xarray/core/alignment.py:761, in align(join, copy, indexes, exclude, fill_value, *objects) 566 """ 567 Given any number of Dataset and/or DataArray objects, returns new 568 objects with aligned indexes and dimension sizes. (...) 751 752 """ 753 aligner = Aligner( 754 objects, 755 join=join, (...) 759 fill_value=fill_value, 760 ) --> 761 aligner.align() 762 return aligner.results

File ~/work/python/xarray/xarray/core/alignment.py:549, in Aligner.align(self) 547 self.find_matching_unindexed_dims() 548 self.assert_no_index_conflict() --> 549 self.align_indexes() 550 self.assert_unindexed_dim_sizes_equal() 552 if self.join == "override":

File ~/work/python/xarray/xarray/core/alignment.py:395, in Aligner.align_indexes(self) 393 if need_reindex: 394 if self.join == "exact": --> 395 raise ValueError( 396 "cannot align objects with join='exact' where " 397 "index/labels/sizes are not equal along " 398 "these coordinates (dimensions): " 399 + ", ".join(f"{name!r} {dims!r}" for name, dims in key[0]) 400 ) 401 joiner = self._get_index_joiner(index_cls) 402 joined_index = joiner(matching_indexes)

ValueError: cannot align objects with join='exact' where index/labels/sizes are not equal along these coordinates (dimensions): 'time' ('time',) ```

Anything else we need to know?

No response

Environment

xarray main

 
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