issues: 947796627

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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
947796627 MDU6SXNzdWU5NDc3OTY2Mjc= 5620 `xr.where()` does not work like `np.where()`on meshgrids 27021858 closed 0     6 2021-07-19T15:55:10Z 2021-07-20T11:32:45Z 2021-07-20T07:58:18Z NONE      

In case of selecting 2D data, the xarray.where() does not work like numpy.where() . In the documentation you have mentioned that np.where() is the corresponding function for xr.where() but it seems that they are working totally different.

Here is my code:

```python data = xarray.open_dataset('path_to_attached_file') minLat, minLon, maxLat, maxLon = (45.08903556483102, 5.625000000000013, 48.92249926375824, 11.249999999999993) latitudes = data.lat.values longitudes = data.lon.values slice_mask = np.where( (latitudes <= maxLat) & (latitudes > minLat) & (longitudes <= maxLon) & (longitudes > minLon) ) _sliced_data = data.where( (data.lat <= maxLat) & (data.lat > minLat) & (data.lon <= maxLon) & (data.lon > minLon), drop=True, ) _sliced_data.latitude.values.max()

49.305596

latitudes[slice_mask].max()

48.922172

``` I have also tried to translate the numpy result into a boolen DataArray:

```python mask_array = data.copy() mask_array.update({'air_temperature_2m': (("y", "x"), (latitudes <= maxLat) & (latitudes > minLat) & (longitudes <= maxLon) & (longitudes > minLon))})

_sliced_data = data.where( mask_array.air_temperature_2m, drop=True, )

``` There we have the same result. It seems that the masking step does not really works correctly.

Environment:

Output of <tt>xr.show_versions()</tt> INSTALLED VERSIONS ------------------ commit: None python: 3.9.1 (default, Feb 9 2021, 07:55:26) [GCC 8.3.0] python-bits: 64 OS: Linux OS-release: 5.10.0-1033-oem machine: x86_64 processor: byteorder: little LC_ALL: None LANG: C.UTF-8 LOCALE: en_US.UTF-8 libhdf5: 1.12.0 libnetcdf: 4.7.4 xarray: 0.16.2 pandas: 1.2.1 numpy: 1.20.0 scipy: 1.6.0 netCDF4: 1.5.5.1 pydap: None h5netcdf: 0.8.0 h5py: 3.2.1 Nio: None zarr: None cftime: 1.5.0 nc_time_axis: None PseudoNetCDF: None rasterio: None cfgrib: 0.9.8.4 iris: None bottleneck: None dask: 2021.05.0 distributed: None matplotlib: 3.3.4 cartopy: None seaborn: None numbagg: None pint: None setuptools: 53.0.0 pip: 21.0.1 conda: None pytest: 6.1.1 IPython: 7.21.0 sphinx: None

harmonie_knmi_grid_fixture.zip

 
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   completed 13221727 issue

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