pcolormesh fails with gouraud shading #1651
Description
This refers to a question I posted on Stackoverflow https://stackoverflow.com/questions/63776199/cartopy-slow-rendering-with-non-orthographic-projection
When using a 100x100 array (or any size) and using pcolormesh, adding the shading='gouraud' argument fails but using 'flat' is fine.
By not specifying the shading argument, the rendering is super slow compared to using an Orthographic projection. It seems the C array in geoaxes.py is not well defined for the gouraud shading?
Code to reproduce
import numpy as np
import matplotlib.pyplot as plt
import cartopy
import cartopy.crs as ccrs
import time
# Data
# Notice: we can use either phi ∈ [-180, 180] OR phi ∈ [0, 360]
phi = np.linspace(0, 2 * np.pi, 100)
lat = np.linspace(-np.pi / 2, np.pi / 2, 100)
# NOTICE: that PI is defined in the -z direction
theta = (lat + np.pi / 2)[::-1]
data = np.zeros((len(theta), len(phi)), dtype=np.float64)
for j, Th in enumerate(theta):
for i, Ph in enumerate(phi):
data[j, i] = Ph # plot by longitude
# Plot
t = time.time()
# Set up figure
fig = plt.figure(figsize=(8, 4))
ax = plt.axes(projection=ccrs.InterruptedGoodeHomolosine())
vlim = np.max(np.abs(data))
p = ax.pcolormesh(phi * 180 / np.pi, lat * 180 / np.pi,
data,
transform=ccrs.PlateCarree(),
cmap='RdBu',vmin=0, vmax=vlim)
ax.autoscale_view()
gl = ax.gridlines(draw_labels=False)
plt.colorbar(p)
plt.show()
print(time.time() - t)Traceback
-----------------------------------------------------------------
ValueError Traceback (most recent call last)
<ipython-input-9-b199a9d7c32c> in <module>
2 ax = plt.axes(projection=ccrs.InterruptedGoodeHomolosine())
3 vlim = np.max(np.abs(data))
----> 4 p = ax.pcolormesh(phi * 180 / np.pi, lat * 180 / np.pi,
5 data,
6 transform=ccrs.PlateCarree(),
~/miniconda3/lib/python3.8/site-packages/cartopy/mpl/geoaxes.py in wrapper(self, *args, **kwargs)
308
309 kwargs['transform'] = transform
--> 310 return func(self, *args, **kwargs)
311 return wrapper
312
~/miniconda3/lib/python3.8/site-packages/cartopy/mpl/geoaxes.py in pcolormesh(self, *args, **kwargs)
1559
1560 """
-> 1561 result = self._pcolormesh_patched(*args, **kwargs)
1562 self.autoscale_view()
1563 return result
~/miniconda3/lib/python3.8/site-packages/cartopy/mpl/geoaxes.py in _pcolormesh_patched(self, *args, **kwargs)
1672 isinstance(self.projection, wrap_proj_types):
1673
-> 1674 C = C.reshape((Ny - 1, Nx - 1))
1675 transformed_pts = transformed_pts.reshape((Ny, Nx, 2))
1676
~/miniconda3/lib/python3.8/site-packages/numpy/ma/core.py in reshape(self, *s, **kwargs)
4650 """
4651 kwargs.update(order=kwargs.get('order', 'C'))
-> 4652 result = self._data.reshape(*s, **kwargs).view(type(self))
4653 result._update_from(self)
4654 mask = self._mask
ValueError: cannot reshape array of size 10000 into shape (99,99)Full environment definition
Operating system
Linux. openSUSE Tumbleweed 20200829
Cartopy version
0.18
conda list
# packages in environment at /home/david/miniconda3:
#
# Name Version Build Channel
_libgcc_mutex 0.1 main
argon2-cffi 20.1.0 pypi_0 pypi
astroid 2.4.2 pypi_0 pypi
attrs 19.3.0 pypi_0 pypi
backcall 0.2.0 pypi_0 pypi
beautifulsoup4 4.9.1 pypi_0 pypi
bleach 3.1.5 pypi_0 pypi
ca-certificates 2020.7.22 0
cartopy 0.18.0 pypi_0 pypi
certifi 2020.6.20 pypi_0 pypi
cffi 1.14.0 py38he30daa8_1
chardet 3.0.4 py38_1003
conda 4.8.4 py38_0
conda-package-handling 1.6.1 py38h7b6447c_0
cryptography 2.9.2 py38h1ba5d50_0
cycler 0.10.0 pypi_0 pypi
cython 0.29.21 pypi_0 pypi
decorator 4.4.2 pypi_0 pypi
defusedxml 0.6.0 pypi_0 pypi
entrypoints 0.3 pypi_0 pypi
flake8 3.8.3 pypi_0 pypi
geos 3.8.1 he6710b0_0
greenlet 0.4.16 pypi_0 pypi
icu 58.2 he6710b0_3
idna 2.9 py_1
iniconfig 1.0.1 pypi_0 pypi
ipykernel 5.3.4 pypi_0 pypi
ipython 7.17.0 pypi_0 pypi
ipython-genutils 0.2.0 pypi_0 pypi
ipywidgets 7.5.1 pypi_0 pypi
isort 4.3.21 pypi_0 pypi
jedi 0.17.2 pypi_0 pypi
jinja2 2.11.2 pypi_0 pypi
json5 0.9.5 pypi_0 pypi
jsonschema 3.2.0 pypi_0 pypi
jupyter 1.0.0 pypi_0 pypi
jupyter-client 6.1.6 pypi_0 pypi
jupyter-console 6.1.0 pypi_0 pypi
jupyter-core 4.6.3 pypi_0 pypi
jupyterlab 2.2.5 pypi_0 pypi
jupyterlab-server 1.2.0 pypi_0 pypi
jupytext 1.6.0 pypi_0 pypi
kiwisolver 1.2.0 pypi_0 pypi
lazy-object-proxy 1.4.3 pypi_0 pypi
ld_impl_linux-64 2.33.1 h53a641e_7
libedit 3.1.20181209 hc058e9b_0
libffi 3.3 he6710b0_1
libgcc-ng 9.1.0 hdf63c60_0
libstdcxx-ng 9.1.0 hdf63c60_0
libxml2 2.9.10 he19cac6_1
libxslt 1.1.34 hc22bd24_0
lxml 4.5.2 py38hefd8a0e_0
markdown-it-py 0.5.3 pypi_0 pypi
markupsafe 1.1.1 pypi_0 pypi
matplotlib 3.3.1 pypi_0 pypi
mccabe 0.6.1 pypi_0 pypi
mistune 0.8.4 pypi_0 pypi
more-itertools 8.5.0 pypi_0 pypi
msgpack 1.0.0 pypi_0 pypi
multipole-inversion 0.1 pypi_0 pypi
mypy 0.782 pypi_0 pypi
mypy-extensions 0.4.3 pypi_0 pypi
nbconvert 5.6.1 pypi_0 pypi
nbformat 5.0.7 pypi_0 pypi
ncurses 6.2 he6710b0_1
neovim 0.3.1 pypi_0 pypi
notebook 6.1.3 pypi_0 pypi
numpy 1.19.1 pypi_0 pypi
openssl 1.1.1g h7b6447c_0
packaging 20.4 pypi_0 pypi
pandocfilters 1.4.2 pypi_0 pypi
parso 0.7.1 pypi_0 pypi
pathlib 1.0.1 pypi_0 pypi
pep8 1.7.1 pypi_0 pypi
pexpect 4.8.0 pypi_0 pypi
pickleshare 0.7.5 pypi_0 pypi
pillow 7.2.0 pypi_0 pypi
pip 20.0.2 py38_3
pluggy 0.13.1 pypi_0 pypi
proj 6.2.1 haa6030c_0
prometheus-client 0.8.0 pypi_0 pypi
prompt-toolkit 3.0.6 pypi_0 pypi
psutil 5.7.2 pypi_0 pypi
ptyprocess 0.6.0 pypi_0 pypi
py 1.9.0 pypi_0 pypi
pycodestyle 2.6.0 pypi_0 pypi
pycosat 0.6.3 py38h7b6447c_1
pycparser 2.20 py_0
pyflakes 2.2.0 pypi_0 pypi
pygments 2.6.1 pypi_0 pypi
pylint 2.5.3 pypi_0 pypi
pynvim 0.4.1 pypi_0 pypi
pyopenssl 19.1.0 py38_0
pyparsing 2.4.7 pypi_0 pypi
pyrsistent 0.16.0 pypi_0 pypi
pyshp 2.1.0 pypi_0 pypi
pysocks 1.7.1 py38_0
pytest 6.0.1 pypi_0 pypi
python 3.8.3 hcff3b4d_0
python-dateutil 2.8.1 pypi_0 pypi
pyvtk 0.5.18 pypi_0 pypi
pyyaml 5.3.1 pypi_0 pypi
pyzmq 19.0.2 pypi_0 pypi
qtconsole 4.7.6 pypi_0 pypi
qtpy 1.9.0 pypi_0 pypi
readline 8.0 h7b6447c_0
requests 2.23.0 py38_0
ruamel_yaml 0.15.87 py38h7b6447c_0
scipy 1.5.2 pypi_0 pypi
send2trash 1.5.0 pypi_0 pypi
setuptools 46.4.0 py38_0
shapely 1.8.dev0 pypi_0 pypi
six 1.14.0 py38_0
soupsieve 2.0.1 pypi_0 pypi
sqlite 3.31.1 h62c20be_1
terminado 0.8.3 pypi_0 pypi
testpath 0.4.4 pypi_0 pypi
tk 8.6.8 hbc83047_0
toml 0.10.1 pypi_0 pypi
tornado 6.0.4 pypi_0 pypi
tqdm 4.46.0 py_0
traitlets 4.3.3 pypi_0 pypi
typed-ast 1.4.1 pypi_0 pypi
typing-extensions 3.7.4.2 pypi_0 pypi
urllib3 1.25.8 py38_0
wcwidth 0.2.5 pypi_0 pypi
webencodings 0.5.1 pypi_0 pypi
wheel 0.34.2 py38_0
widgetsnbextension 3.5.1 pypi_0 pypi
wrapt 1.12.1 pypi_0 pypi
xz 5.2.5 h7b6447c_0
yaml 0.1.7 had09818_2
zlib 1.2.11 h7b6447c_3
pip list
Package Version
---------------------- -------------------
argon2-cffi 20.1.0
astroid 2.4.2
attrs 19.3.0
backcall 0.2.0
beautifulsoup4 4.9.1
bleach 3.1.5
Cartopy 0.18.0
certifi 2020.6.20
cffi 1.14.0
chardet 3.0.4
conda 4.8.4
conda-package-handling 1.7.0
cryptography 2.9.2
cycler 0.10.0
Cython 0.29.21
decorator 4.4.2
defusedxml 0.6.0
entrypoints 0.3
flake8 3.8.3
greenlet 0.4.16
idna 2.9
iniconfig 1.0.1
ipykernel 5.3.4
ipython 7.17.0
ipython-genutils 0.2.0
ipywidgets 7.5.1
isort 4.3.21
jedi 0.17.2
Jinja2 2.11.2
json5 0.9.5
jsonschema 3.2.0
jupyter 1.0.0
jupyter-client 6.1.6
jupyter-console 6.1.0
jupyter-core 4.6.3
jupyterlab 2.2.5
jupyterlab-server 1.2.0
jupytext 1.6.0
kiwisolver 1.2.0
lazy-object-proxy 1.4.3
lxml 4.5.2
markdown-it-py 0.5.3
MarkupSafe 1.1.1
matplotlib 3.3.1
mccabe 0.6.1
mistune 0.8.4
more-itertools 8.5.0
msgpack 1.0.0
multipole-inversion 0.1
mypy 0.782
mypy-extensions 0.4.3
nbconvert 5.6.1
nbformat 5.0.7
neovim 0.3.1
notebook 6.1.3
numpy 1.19.1
packaging 20.4
pandocfilters 1.4.2
parso 0.7.1
pathlib 1.0.1
pep8 1.7.1
pexpect 4.8.0
pickleshare 0.7.5
Pillow 7.2.0
pip 20.0.2
pluggy 0.13.1
prometheus-client 0.8.0
prompt-toolkit 3.0.6
psutil 5.7.2
ptyprocess 0.6.0
py 1.9.0
pycodestyle 2.6.0
pycosat 0.6.3
pycparser 2.20
pyflakes 2.2.0
Pygments 2.6.1
pylint 2.5.3
pynvim 0.4.1
pyOpenSSL 19.1.0
pyparsing 2.4.7
pyrsistent 0.16.0
pyshp 2.1.0
PySocks 1.7.1
pytest 6.0.1
python-dateutil 2.8.1
PyVTK 0.5.18
PyYAML 5.3.1
pyzmq 19.0.2
qtconsole 4.7.6
QtPy 1.9.0
requests 2.23.0
ruamel-yaml 0.15.87
scipy 1.5.2
Send2Trash 1.5.0
setuptools 46.4.0.post20200518
Shapely 1.8.dev0
six 1.14.0
soupsieve 2.0.1
terminado 0.8.3
testpath 0.4.4
toml 0.10.1
tornado 6.0.4
tqdm 4.46.0
traitlets 4.3.3
typed-ast 1.4.1
typing-extensions 3.7.4.2
urllib3 1.25.8
wcwidth 0.2.5
webencodings 0.5.1
wheel 0.34.2
widgetsnbextension 3.5.1
wrapt 1.12.1