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pcolor deprecation warning with default settings #18546
Description
Bug report
Bug summary
pcolor() produces a deprecation warning with default settings.
The default of rcParams['pcolor.shading'] seems to be 'flat', which is deprecated (at least sometimes). Maybe the default should be changed to 'auto' or 'nearest'?
Code for reproduction
from matplotlib import pyplot as plt
import numpy as np
x = np.arange(2.)
y = np.arange(2.)
z = np.ones([2,2])
plt.pcolor(x,y,z)Actual outcome
MatplotlibDeprecationWarning: shading='flat' when X and Y have the same dimensions as C is deprecated since 3.3. Either specify the corners of the quadrilaterals with X and Y, or pass shading='auto', 'nearest' or 'gouraud', or set rcParams['pcolor.shading']. This will become an error two minor releases later.
plt.pcolor(x,y,z)
Expected outcome
No warning
Matplotlib version
- Operating system: Linux Mint 19
- Matplotlib version: 3.3.2
- Matplotlib backend (
print(matplotlib.get_backend())): Qt5Agg - Python version: 3.7.6
- Jupyter version (if applicable): N/A
- Other libraries: None
Installed with conda from conda-forge
Activity
jklymak commentedon Sep 22, 2020
This was purposefully done. "flat" was the previous default, and we need a deprecation period before we change it. If you wish to avoid the warning, then you can manually do what flat does in this case and drop the extra row and column:
See #16258 for a discussion.
I guess its a question of whether we have deprecated this long enough to change the default.
johnomotani commentedon Sep 22, 2020
OK, that makes sense. Thanks @jklymak! BTW I think the new
"nearest"is much better!