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 2180430069,I_kwDOAMm_X86B9rj1,8820,"""ValueError: dimensions [...] must have the same length as the number of data dimensions"" when slicing by zero-dimensional CuPy array",404832,open,0,,,0,2024-03-11T23:21:34Z,2024-03-11T23:21:34Z,,CONTRIBUTOR,,,,"### What happened? I'm slicing a DataArray by another zero-dimensional array. It works as I would expect when the DataArray and indexing array are backed by NumPy, but not when they're CuPy arrays: ```python a = xr.DataArray(cp.arange(24).reshape(4, 6), dims=['x', 'y']) idx = xr.DataArray(cp.array(2)) print(a.isel(x=idx)) ``` which results in: ``` Traceback (most recent call last): File ""/home/darsh/work/dr-0338/example.py"", line 8, in print(a.isel(x=idx)) ^^^^^^^^^^^^^ File ""/home/darsh/virtualenvs/python3.11/lib/python3.11/site-packages/xarray/core/dataarray.py"", line 1471, in isel ds = self._to_temp_dataset()._isel_fancy( ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File ""/home/darsh/virtualenvs/python3.11/lib/python3.11/site-packages/xarray/core/dataset.py"", line 2994, in _isel_fancy new_var = var.isel(indexers=var_indexers) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File ""/home/darsh/virtualenvs/python3.11/lib/python3.11/site-packages/xarray/core/variable.py"", line 993, in isel return self[key] ~~~~^^^^^ File ""/home/darsh/virtualenvs/python3.11/lib/python3.11/site-packages/xarray/core/variable.py"", line 767, in __getitem__ return self._finalize_indexing_result(dims, data) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File ""/home/darsh/virtualenvs/python3.11/lib/python3.11/site-packages/xarray/core/variable.py"", line 771, in _finalize_indexing_result return self._replace(dims=dims, data=data) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File ""/home/darsh/virtualenvs/python3.11/lib/python3.11/site-packages/xarray/core/variable.py"", line 917, in _replace return type(self)(dims, data, attrs, encoding, fastpath=True) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File ""/home/darsh/virtualenvs/python3.11/lib/python3.11/site-packages/xarray/core/variable.py"", line 365, in __init__ super().__init__( File ""/home/darsh/virtualenvs/python3.11/lib/python3.11/site-packages/xarray/namedarray/core.py"", line 264, in __init__ self._dims = self._parse_dimensions(dims) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File ""/home/darsh/virtualenvs/python3.11/lib/python3.11/site-packages/xarray/namedarray/core.py"", line 490, in _parse_dimensions raise ValueError( ValueError: dimensions ('x', 'y') must have the same length as the number of data dimensions, ndim=1 ``` ### What did you expect to happen? If the example is run with NumPy arrays instead of CuPy arrays, we get this, as expected: ``` Size: 48B array([12, 13, 14, 15, 16, 17]) Dimensions without coordinates: y ``` ### Minimal Complete Verifiable Example ```Python #!/usr/bin/env python3 import cupy as cp import xarray as xr a = xr.DataArray(cp.arange(24).reshape(4, 6), dims=['x', 'y']) idx = xr.DataArray(cp.array(2)) print(a.isel(x=idx)) ``` ### MVCE confirmation - [X] Minimal example — the example is as focused as reasonably possible to demonstrate the underlying issue in xarray. - [X] Complete example — the example is self-contained, including all data and the text of any traceback. - [X] Verifiable example — the example copy & pastes into an IPython prompt or [Binder notebook](https://mybinder.org/v2/gh/pydata/xarray/main?urlpath=lab/tree/doc/examples/blank_template.ipynb), returning the result. - [X] New issue — a search of GitHub Issues suggests this is not a duplicate. - [X] Recent environment — the issue occurs with the latest version of xarray and its dependencies. ### Relevant log output ```Python Traceback (most recent call last): File ""/home/darsh/work/dr-0338/example.py"", line 8, in print(a.isel(x=idx)) ^^^^^^^^^^^^^ File ""/home/darsh/virtualenvs/python3.11/lib/python3.11/site-packages/xarray/core/dataarray.py"", line 1471, in isel ds = self._to_temp_dataset()._isel_fancy( ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File ""/home/darsh/virtualenvs/python3.11/lib/python3.11/site-packages/xarray/core/dataset.py"", line 2994, in _isel_fancy new_var = var.isel(indexers=var_indexers) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File ""/home/darsh/virtualenvs/python3.11/lib/python3.11/site-packages/xarray/core/variable.py"", line 993, in isel return self[key] ~~~~^^^^^ File ""/home/darsh/virtualenvs/python3.11/lib/python3.11/site-packages/xarray/core/variable.py"", line 767, in __getitem__ return self._finalize_indexing_result(dims, data) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File ""/home/darsh/virtualenvs/python3.11/lib/python3.11/site-packages/xarray/core/variable.py"", line 771, in _finalize_indexing_result return self._replace(dims=dims, data=data) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File ""/home/darsh/virtualenvs/python3.11/lib/python3.11/site-packages/xarray/core/variable.py"", line 917, in _replace return type(self)(dims, data, attrs, encoding, fastpath=True) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File ""/home/darsh/virtualenvs/python3.11/lib/python3.11/site-packages/xarray/core/variable.py"", line 365, in __init__ super().__init__( File ""/home/darsh/virtualenvs/python3.11/lib/python3.11/site-packages/xarray/namedarray/core.py"", line 264, in __init__ self._dims = self._parse_dimensions(dims) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File ""/home/darsh/virtualenvs/python3.11/lib/python3.11/site-packages/xarray/namedarray/core.py"", line 490, in _parse_dimensions raise ValueError( ValueError: dimensions ('x', 'y') must have the same length as the number of data dimensions, ndim=1 ``` ### Anything else we need to know? I briefly looked into this but haven't discovered the cause yet. What I know: - It appears the buggy behavior was introduced in version 2023.3.0. With 2023.2.0, it gives the correct output. - I confirmed in the debugger that the indexing operation itself seems to work, and it's really just the dimensions `('x', 'y')` that are computed incorrectly. ### Environment
INSTALLED VERSIONS ------------------ commit: None python: 3.11.8 (main, Feb 25 2024, 16:41:26) [GCC 9.4.0] python-bits: 64 OS: Linux OS-release: 5.15.0-100-generic machine: x86_64 processor: x86_64 byteorder: little LC_ALL: None LANG: en_US.UTF-8 LOCALE: ('en_US', 'UTF-8') libhdf5: None libnetcdf: None xarray: 2024.2.0 pandas: 1.5.3 numpy: 1.26.4 scipy: None netCDF4: None pydap: None h5netcdf: None h5py: None Nio: None zarr: None cftime: None nc_time_axis: None iris: None bottleneck: None dask: None distributed: None matplotlib: None cartopy: None seaborn: None numbagg: None fsspec: None cupy: 13.0.0 pint: None sparse: None flox: None numpy_groupies: None setuptools: None pip: None conda: None pytest: None mypy: None IPython: None sphinx: None
","{""url"": ""https://api.github.com/repos/pydata/xarray/issues/8820/reactions"", ""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,,13221727,issue 903055859,MDU6SXNzdWU5MDMwNTU4NTk=,5384,"Regression: ""ValueError: cannot unstack dimensions that do not have a MultiIndex"" when unstacking a MultiIndex",404832,closed,0,,,5,2021-05-27T00:34:27Z,2021-05-28T08:28:11Z,2021-05-28T08:28:11Z,CONTRIBUTOR,,,," I'm not sure if this is a bug or I'm not using `xarray` correctly, but I used to be able to do this without crashing. The new behavior seems to have been introduced some time between 0.16.2 and 0.18.2. **What happened**: ```python traceback Traceback (most recent call last): File ""scripts/repro.py"", line 12, in ds = ds.unstack(['c']) File ""/home/darsh/src/notebooks/build/venv/lib/python3.8/site-packages/xarray/core/dataset.py"", line 4024, in unstack raise ValueError( ValueError: cannot unstack dimensions that do not have a MultiIndex: ['c'] ``` **What you expected to happen**: The code runs without the `ValueError` exception. **Minimal Complete Verifiable Example**: ```python from xarray import DataArray, Dataset a = DataArray([0], dims=['a']) b = a.stack(b=('a',)).reset_index('b') c = b.stack({'c': ['b']}) ds = Dataset({'d': DataArray(c.data, dims=['c'])}, coords=c.coords) print('\nBefore:') print(ds) ds = ds.unstack(['c']) print('\nAfter:') print(ds) ``` **Anything else we need to know?**: Here's the full output from the example on 0.18.2: ``` Before: Dimensions: (c: 1) Coordinates: * c (c) MultiIndex - b (c) int64 0 a (c) int64 0 Data variables: d (c) int64 0 Traceback (most recent call last): File ""scripts/repro.py"", line 12, in ds = ds.unstack(['c']) File ""/home/darsh/src/notebooks/build/venv/lib/python3.8/site-packages/xarray/core/dataset.py"", line 4024, in unstack raise ValueError( ValueError: cannot unstack dimensions that do not have a MultiIndex: ['c'] ``` What confuses me is that the `c` dimension is shown as a `MultiIndex`, but it still complains that it doesn't have a `MultiIndex`. Directly unstacking `ds.d` rather than the dataset itself also fails with the same exception. Oddly, it seems to work if I assign the coordinates after constructing the dataset: ```diff diff --git a/scripts/repro.py b/scripts/repro.py index ed2ae7c..d5bd6a3 100644 --- a/scripts/repro.py +++ b/scripts/repro.py @@ -5,7 +5,7 @@ a = DataArray([0], dims=['a']) b = a.stack(b=('a',)).reset_index('b') c = b.stack({'c': ['b']}) -ds = Dataset({'d': DataArray(c.data, dims=['c'])}, coords=c.coords) +ds = Dataset({'d': DataArray(c.data, dims=['c'])}).assign_coords(c.coords) print('\nBefore:') print(ds) ``` With that workaround, or by downgrading to 0.16.2, the example doesn't crash: ``` Before: Dimensions: (c: 1) Coordinates: * c (c) MultiIndex - b (c) int64 0 a (c) int64 0 Data variables: d (c) int64 0 After: Dimensions: (b: 1) Coordinates: a (b) int64 0 * b (b) int64 0 Data variables: d (b) int64 0 ``` **Environment**:
Output of xr.show_versions() INSTALLED VERSIONS ------------------ commit: None python: 3.8.0 (default, Feb 25 2021, 22:10:10) [GCC 8.4.0] python-bits: 64 OS: Linux OS-release: 5.4.0-73-generic machine: x86_64 processor: x86_64 byteorder: little LC_ALL: None LANG: en_US.UTF-8 LOCALE: ('en_US', 'UTF-8') libhdf5: None libnetcdf: None xarray: 0.18.2 pandas: 1.2.4 numpy: 1.20.3 scipy: 1.6.3 netCDF4: None pydap: None h5netcdf: None h5py: None Nio: None zarr: None cftime: None nc_time_axis: None PseudoNetCDF: None rasterio: None cfgrib: None iris: None bottleneck: None dask: 2021.05.0 distributed: None matplotlib: 3.4.2 cartopy: None seaborn: None numbagg: None pint: 0.17 setuptools: 39.0.1 pip: 21.1.1 conda: None pytest: 6.2.4 IPython: 7.23.1 sphinx: None None
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