Bug contourf

Description

I’m running into an error after upgrading the proplot version . The error occurs when using contourf, the error message is KeyError: ‘red’

Steps to reproduce

# your code here
# we should be able to copy-paste this into python and exactly reproduce your bug

import proplot as plot
import matplotlib.pyplot as plt
import numpy as np

f, axs = plot.subplots(ncols=1, nrows=1) 

#generate random data
data=np.ones((180,360))
data[20:80,80:150]+=1

x=np.arange(0,360,1)
y=np.arange(0,180,1)

axs.contourf(x,y,data,cmap=plt.cm.coolwarm)

plt.show()

Expected behavior: A simple contourf plot

Actual behavior: An error message occured and the plot was not produced

Equivalent steps in matplotlib

Pretty sure its Proplot. With matplotlib this works

import matplotlib.pyplot as plt
import numpy as np

f,axs=plt.subplots()

#generate random data
data=np.ones((180,360))
data[20:80,80:150]+=1
x=np.arange(0,360,1)
y=np.arange(0,180,1)

axs.contourf(x,y,data,cmap=plt.cm.coolwarm)
plt.show()

Proplot version

Matplotlib: 3.4.1 Proplot: 0.9.1

[lukelbd]

No problem. Thanks for your clarification – after that I found the solution relatively quickly (182a186).

The Colormap constructor function converts input native matplotlib colormaps to proplot’s colormap subclasses (i.e. ListedColormap to DiscreteColormap, LinearSegmentedColormap to ContinuousColormap). There was a bug in the conversion process that caused erasure of the original segmentdata. This happened the first time the native matplotlib colormap was passed through Colormap (i.e., the first hist2d call). To fix this, I simply make sure to copy the native colormap segment data dictionary before using it for the new colormap.

[ghost]

Thanks @matthias-k for digging further and @lukelbd for addressing the issue so quickly!