Geographic Filled KDE Plot

[bschweigert]

I am plotting lat/lon points on a geographic map, and I would like to underlay a KDE plot beneath scatter points. Because they are lat/lon points, the plotting will use a cartopy transform (in my case PlateCarree). When calling the kdeplot function with fill=False, everything works fine. However, with fill = True it returns the error:

AttributeError: 'PlateCarree' object has no attribute 'contains_branch_seperately'

Here is reproducible code:

import numpy as np
import seaborn as sns
import cartopy.crs as ccrs
import matplotlib.pyplot as plt
import cartopy.feature as cfeature

##Create example lat/lon points
lons = np.random.uniform(low = -100, high = -90, size = 20)
lats = np.random.uniform(low = 30, high = 40, size = 20)

##Create the figure
fig = plt.figure(figsize = (6, 4), dpi = 300)
ax = fig.add_subplot(1, 1, 1, projection = ccrs.LambertConformal())

##Add features
ax.add_feature(cfeature.STATES.with_scale('50m'), zorder = 1)
ax.set_extent((-103, -88, 22.5, 42))

##Scatter plot the lat/lon points
ax.scatter(lons, lats, c = 'black', marker = 'x', transform = ccrs.PlateCarree(), zorder = 2)

##Add a KDE underlay
kde = sns.kdeplot(x = lons, y = lats, fill = True, transform = ccrs.PlateCarree(), zorder = 1)

[mwaskom]

hm this smells like something between matplotlib and cartopy, that's not a function seaborn is calling directly. can you share the full traceback?

[bschweigert]

Here is the full traceback:

File ~\Miniconda3\envs\figs\Lib\site-packages\spyder_kernels\py3compat.py:356 in compat_exec
exec(code, globals, locals)

File c:\users\bschweigert2\desktop\lm clim\error_ex.py:28
kde = sns.kdeplot(x = lons, y = lats, fill = True, transform = ccrs.PlateCarree(), zorder = 1)

File ~\Miniconda3\envs\figs\Lib\site-packages\seaborn\distributions.py:1682 in kdeplot
color = _default_color(method, hue, color, kwargs)

File ~\Miniconda3\envs\figs\Lib\site-packages\seaborn\utils.py:136 in _default_color
scout = method([], [], **kws)

File ~\Miniconda3\envs\figs\Lib\site-packages\matplotlib_init_.py:1478 in inner
return func(ax, *map(sanitize_sequence, args), **kwargs)

File ~\Miniconda3\envs\figs\Lib\site-packages\matplotlib\axes_axes.py:5509 in fill_between
return self._fill_between_x_or_y(

File ~\Miniconda3\envs\figs\Lib\site-packages\matplotlib\axes_axes.py:5500 in _fill_between_x_or_y
up_x, up_y = kwargs["transform"].contains_branch_seperately(self.transData)

AttributeError: 'PlateCarree' object has no attribute 'contains_branch_seperately'

That would be intriguing, because I have done plenty of plotting recently with matplotlib and cartopy with no issues thus far. Thanks for the help!

[mwaskom]

Based on that it seems like you could reproduce this with something like

f, ax = plt.subplots()
ax.fill_between([], [], transform=ccrs.PlateCarree())

(untested as I don't have the relevant geographic dependencies)

[mwaskom]

You may need to set up the subplot with the same projection too, I am not sure.