Unable to run example - Githubissues

Description

Hello, I am unable to run the basic example found here after installing following the given instructions. Installing from source using pip does not help.

I am using Mac OSX 11.3.1.

Traceback:

Python 3.8.5 (default, Sep  4 2020, 02:22:02)
Type 'copyright', 'credits' or 'license' for more information
IPython 7.22.0 -- An enhanced Interactive Python. Type '?' for help.

In [1]: import cartopy.crs as ccrs
   ...: import matplotlib.pyplot as plt
   ...:
   ...: ax = plt.axes(projection=ccrs.Mollweide())
   ...: ax.stock_img()
   ...: plt.show()
Shell is not a LinearRing
Shell is not a LinearRing
---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-1-a662b02540c6> in <module>
      3
      4 ax = plt.axes(projection=ccrs.Mollweide())
----> 5 ax.stock_img()
      6 plt.show()

~/opt/anaconda3/lib/python3.8/site-packages/cartopy/mpl/geoaxes.py in stock_img(self, name)
   1017                                  '50-natural-earth-1-downsampled.png')
   1018
-> 1019             return self.imshow(imread(fname), origin='upper',
   1020                                transform=source_proj,
   1021                                extent=[-180, 180, -90, 90])

~/opt/anaconda3/lib/python3.8/site-packages/cartopy/mpl/geoaxes.py in wrapper(self, *args, **kwargs)
    319
    320         kwargs['transform'] = transform
--> 321         return func(self, *args, **kwargs)
    322     return wrapper
    323

~/opt/anaconda3/lib/python3.8/site-packages/cartopy/mpl/geoaxes.py in imshow(self, img, *args, **kwargs)
   1321                                  'handle a %s in imshow.' % type(transform))
   1322
-> 1323             target_extent = self.get_extent(self.projection)
   1324             regrid_shape = kwargs.pop('regrid_shape', 750)
   1325             regrid_shape = self._regrid_shape_aspect(regrid_shape,

~/opt/anaconda3/lib/python3.8/site-packages/cartopy/mpl/geoaxes.py in get_extent(self, crs)
    766
    767         """
--> 768         p = self._get_extent_geom(crs)
    769         r = p.bounds
    770         x1, y1, x2, y2 = r

~/opt/anaconda3/lib/python3.8/site-packages/cartopy/mpl/geoaxes.py in _get_extent_geom(self, crs)
    814                                                 self.projection)
    815         else:
--> 816             geom_in_crs = boundary_poly.intersection(domain_in_src_proj)
    817
    818         return geom_in_crs

~/opt/anaconda3/lib/python3.8/site-packages/shapely/geometry/base.py in intersection(self, other)
    674     def intersection(self, other):
    675         """Returns the intersection of the geometries"""
--> 676         return geom_factory(self.impl['intersection'](self, other))
    677
    678     def symmetric_difference(self, other):

~/opt/anaconda3/lib/python3.8/site-packages/shapely/topology.py in __call__(self, this, other, *args)
     62
     63     def __call__(self, this, other, *args):
---> 64         self._validate(this)
     65         self._validate(other, stop_prepared=True)
     66         product = self.fn(this._geom, other._geom, *args)

~/opt/anaconda3/lib/python3.8/site-packages/shapely/topology.py in _validate(self, ob, stop_prepared)
     16     def _validate(self, ob, stop_prepared=False):
     17         if ob is None or ob._geom is None:
---> 18             raise ValueError("Null geometry supports no operations")
     19         if stop_prepared and hasattr(ob, 'prepared'):
     20             raise ValueError("Prepared geometries cannot be operated on")

ValueError: Null geometry supports no operations

I'm getting a slightly different error using the same example. Everything goes well until the plt.show() command

`Shell is not a LinearRing Shell is not a LinearRing /Users/deborahkhider/opt/anaconda3/envs/pyleoclim/lib/python3.8/site-packages/cartopy/mpl/feature_artist.py:152: UserWarning: Unable to determine extent. Defaulting to global. warnings.warn('Unable to determine extent. Defaulting to global.') Shell is not a LinearRing Traceback (most recent call last):

File "/Users/deborahkhider/opt/anaconda3/envs/pyleoclim/lib/python3.8/site-packages/IPython/core/formatters.py", line 341, in call return printer(obj)

File "/Users/deborahkhider/opt/anaconda3/envs/pyleoclim/lib/python3.8/site-packages/IPython/core/pylabtools.py", line 248, in png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))

File "/Users/deborahkhider/opt/anaconda3/envs/pyleoclim/lib/python3.8/site-packages/IPython/core/pylabtools.py", line 132, in print_figure fig.canvas.print_figure(bytes_io, **kw)

File "/Users/deborahkhider/opt/anaconda3/envs/pyleoclim/lib/python3.8/site-packages/matplotlib/backend_bases.py", line 2193, in print_figure self.figure.draw(renderer)