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/4061#issuecomment-977165503,https://api.github.com/repos/pydata/xarray/issues/4061,977165503,IC_kwDOAMm_X846Ply_,33153877,2021-11-23T21:01:17Z,2021-11-23T21:01:17Z,NONE,"I also have an issue where xarray doesn't produce the correct plot when normalizing with BoundaryNorm:
```python
import xarray as xr
import matplotlib.pyplot as plt
import matplotlib.colors as colors
from cmcrameri import cm
airtemps = xr.tutorial.open_dataset(""air_temperature"")
# Convert to Celsius.
air = airtemps.air - 273.15
air.attrs = airtemps.air.attrs
air.attrs[""units""] = ""deg C""
# Select a timestep.
air2d = air.isel(time=500)
# Plotting discrete bounds with matplotlib works fine.
bounds = [x for x in range(-30, 31, 10)]
norm = colors.BoundaryNorm(boundaries=bounds, extend='both', ncolors=cm.vik.N)
fig, ax = plt.subplots()
cs = ax.pcolormesh(air2d.lon, air2d.lat, air2d, cmap=cm.vik, norm=norm)
fig.colorbar(cs)
plt.show()
# Plotting with xarray doesn't work.
fig, ax = plt.subplots()
air2d.plot.pcolormesh(ax=ax, norm=norm)
plt.show()
```
First one is from matplotlib:
Second one is from xarray:
I also get the following traceback after running the script:
```bash
Traceback (most recent call last):
File ""/home/michael/miniconda3/envs/testing_xarray/lib/python3.10/site-packages/matplotlib/cbook/__init__.py"", line 287, in process
func(*args, **kwargs)
File ""/home/michael/miniconda3/envs/testing_xarray/lib/python3.10/site-packages/matplotlib/backend_bases.py"", line 3056, in mouse_move
s = self._mouse_event_to_message(event)
File ""/home/michael/miniconda3/envs/testing_xarray/lib/python3.10/site-packages/matplotlib/backend_bases.py"", line 3048, in _mouse_event_to_message
data_str = a.format_cursor_data(data).rstrip()
File ""/home/michael/miniconda3/envs/testing_xarray/lib/python3.10/site-packages/matplotlib/artist.py"", line 1282, in format_cursor_data
neighbors = self.norm.inverse(
File ""/home/michael/miniconda3/envs/testing_xarray/lib/python3.10/site-packages/matplotlib/colors.py"", line 1832, in inverse
raise ValueError(""BoundaryNorm is not invertible"")
ValueError: BoundaryNorm is not invertible
```
Output of xr.show_versions()
INSTALLED VERSIONS
------------------
commit: None
python: 3.10.0 | packaged by conda-forge | (default, Nov 20 2021, 02:25:18) [GCC 9.4.0]
python-bits: 64
OS: Linux
OS-release: 5.14.18-300.fc35.x86_64
machine: x86_64
processor: x86_64
byteorder: little
LC_ALL: None
LANG: en_GB.UTF-8
LOCALE: ('en_GB', 'UTF-8')
libhdf5: 1.12.1
libnetcdf: 4.8.1
xarray: 0.20.1
pandas: 1.3.4
numpy: 1.21.4
scipy: 1.7.2
netCDF4: 1.5.8
pydap: None
h5netcdf: None
h5py: None
Nio: None
zarr: None
cftime: 1.5.1.1
nc_time_axis: None
PseudoNetCDF: None
rasterio: None
cfgrib: None
iris: None
bottleneck: None
dask: None
distributed: None
matplotlib: 3.5.0
cartopy: 0.20.1
seaborn: None
numbagg: None
fsspec: None
cupy: None
pint: None
sparse: None
setuptools: 59.2.0
pip: 21.3.1
conda: None
pytest: None
IPython: 7.29.0
sphinx: None