from mpl_toolkits.basemap import Basemap import matplotlib.pyplot as plt import numpy as np # set up orthographic map projection with # perspective of satellite looking down at 50N, 100W. # use low resolution coastlines. map = Basemap(projection='ortho',lat_0=50,lon_0=-100,resolution='l') # draw coastlines, country boundaries, fill continents. map.drawcoastlines(linewidth=0.25) map.drawcountries(linewidth=0.25) map.fillcontinents(color='coral') # draw the edge of the map projection region (the projection limb) map.drawmapboundary() # draw lat/lon grid lines every 30 degrees. map.drawmeridians(np.arange(0,360,30)) map.drawparallels(np.arange(-90,90,30)) # lat/lon coordinates of five cities. lats=[40.02,32.73,38.55,48.25,17.29] lons=[-105.16,-117.16,-77.00,-114.21,-88.10] cities=['Boulder, CO','San Diego, CA', 'Washington, DC','Whitefish, MT','Belize City, Belize'] # compute the native map projection coordinates for cities. xc,yc = map(lons,lats) # plot filled circles at the locations of the cities. map.plot(xc,yc,'bo') # plot the names of those five cities. for name,xpt,ypt in zip(cities,xc,yc): plt.text(xpt+50000,ypt+50000,name,fontsize=9) # make up some data on a regular lat/lon grid. nlats = 73; nlons = 145; delta = 2.*np.pi/(nlons-1) lats = (0.5*np.pi-delta*np.indices((nlats,nlons))[0,:,:]) lons = (delta*np.indices((nlats,nlons))[1,:,:]) wave = 0.75*(np.sin(2.*lats)**8*np.cos(4.*lons)) mean = 0.5*np.cos(2.*lats)*((np.sin(2.*lats))**2 + 2.) # compute native map projection coordinates of lat/lon grid. x, y = map(lons*180./np.pi, lats*180./np.pi) # contour data over the map. cs = map.contour(x,y,wave+mean,15,linewidths=1.5) # as above, but use blue marble image as map background. fig = plt.figure() map.drawmapboundary() map.drawmeridians(np.arange(0,360,30)) map.drawparallels(np.arange(-90,90,30)) # plot filled circles at the locations of the cities. map.plot(xc,yc,'wo') # plot the names of five cities. for name,xpt,ypt in zip(cities,xc,yc): plt.text(xpt+50000,ypt+50000,name,fontsize=9,color='w') # contour data over the map. cs = map.contour(x,y,wave+mean,15,linewidths=1.5) # draw blue marble image in background. map.bluemarble(scale=0.5) plt.show()