cubed_sphere.py

from __future__ import (absolute_import, division, print_function)

frommpl_toolkits.basemapimportBasemap
importmatplotlib.pyplotasplt
importnumpyasnp

# 'cubed sphere'
# inscribe the sphere in a cube, then separately project each cube
# face with gnomonic projection.
# http://www.progonos.com/furuti/MapProj/Normal/ProjPoly/Foldout/Cube/cube.html
# suitable for cutting and folding.

# choose figure size to match aspect ratio of map.
fig=plt.figure(figsize=(10,7.5))
fig.subplots_adjust(bottom=0, left=0, right=1, top=1, wspace=0, hspace=0)
rsphere=6370997.
width=2.*rsphere; height=width
npanel=0
forlat_0in [90,0,-90]:
forncolinrange(0,4):
npanel=npanel+1
iflat_0==0orncol==1:
ax=fig.add_subplot(3,4,npanel)
ax.set_frame_on(False)
lon_0=225+90*(ncol+1) -45
# use fix_aspect=False, so white space won't appear between
# faces of cube when window is resized.
m=Basemap(width=width,height=height,resolution=None,\
projection='gnom',lon_0=lon_0,lat_0=lat_0,\
rsphere=rsphere,fix_aspect=False)
m.bluemarble(scale=0.5)
m.drawparallels(np.arange(-90,91,10),color='0.5')
m.drawmeridians(np.arange(5,365,10),color='0.5')
#m.drawlsmask(ocean_color='aqua',land_color='coral')
#m.drawparallels(np.arange(-90,91,10))
#m.drawmeridians(np.arange(5,365,10))
fig.text(0.625,0.75,\
'World Map on a Cube\n Gnomonic Projection',\
fontsize=14)
plt.show()