The problem is exactly the same as the one reported here and using the same code:
import matplotlib.pyplot as plt
from mpl_toolkits.basemap import Basemap
plt.figure(figsize=(8, 8))
m = Basemap(projection='ortho', resolution=None, lat_0=50, lon_0=-100)
m.bluemarble(scale=0.5)
plt.show()
This results in the same empty circle. I do get a warning:
Clipping input data to the valid range for imshow with RGB data ([0..1] for floats or [0..255] for integers).
which results from the input data to imshow()
being all zero. If I run the code without the projection
m = Basemap(resolution=None, lat_0=50, lon_0=-100)
I get (rather badly drawn) map of the world, which suggests to me that all the libraries are installed.
I think the data gets zeroed out with the code here from mpl_toolkits\basemap\__init__.py
but as I don't understand what it's doing it doesn't help me much:
self._bm_rgba_warped = \
ma.masked_array(self._bm_rgba_warped,mask=mask)
# make points outside projection limb transparent.
self._bm_rgba_warped = self._bm_rgba_warped.filled(0.)
Any suggestions as to how to proceed?