Merge branch 'master' of github.com:HHammond/basemap

Author: Henry Hammond

examples/nytolondon.py

@@ -17,12 +17,14 @@
 # lonlat, lonlon are lat/lon of London.
 lonlat = 51.53
 lonlon = 0.08
+
 # find 1000 points along the great circle.
 #x,y = m.gcpoints(nylon,nylat,lonlon,lonlat,1000)
 # draw the great circle.
 #m.plot(x,y,linewidth=2)
 # drawgreatcircle performs the previous 2 steps in one call.
 m.drawgreatcircle(nylon,nylat,lonlon,lonlat,linewidth=2,color='b')
+
 m.drawcoastlines()
 m.fillcontinents()
 # draw parallels
@@ -46,6 +48,7 @@
 # lonlat, lonlon are lat/lon of London.
 lonlat = 51.53
 lonlon = 0.08
+
 # find 1000 points along the great circle.
 #x,y = m.gcpoints(nylon,nylat,lonlon,lonlat,1000)
 # draw the great circle.
@@ -63,3 +66,55 @@
 plt.title('Great Circle from New York to London (Gnomonic)')
 sys.stdout.write('plotting Great Circle from New York to London (Gnomonic)\n')
 plt.show()
+
+
+# Example of Great Circles which exit and reenter the map
+m = Basemap(projection='robin', lat_0=0, lon_0=0,resolution='c')
+
+m.drawmapboundary(fill_color='#ffffff',color='#ffffff')
+m.fillcontinents(color='#f2f2f2',lake_color='#ffffff')
+m.drawcoastlines(color='#e0e0e0')
+m.drawcountries(color='#e0e0e0')
+
+parallels = np.arange(-90,90,10.)
+meridians = np.arange(10.,351.,20.)
+m.drawparallels(parallels,labels=[False,False,False,False], color='#d3d3d3',dashes=[1,3])
+m.drawmeridians(meridians,labels=[False,False,False,False], color='#d3d3d3',dashes=[1,3])
+
+# Choose the lat and longtitude of two points
+
+p1 = (45.27,-75.42) # roughly Ottawa
+p2 = (44.05,-4.28)  # roughly Paris
+p3 = (-38.58,145.05) # roughly Victoria
+
+la1, lo1 = p1
+la2, lo2 = p2
+la3, lo3 = p3
+
+# Drawing points; you need to convert from lon-lat to xy-cartesian
+x1,y1 = m(lo1,la1)
+x2,y2 = m(lo2,la2)
+x3,y3 = m(lo3,la3)
+
+# Convert back by setting inverse=True
+lon,lat = m(x1,y1,inverse=True)
+
+# Plot pionts using markers
+m.plot(x1,y1, marker='.', markersize=8, color='#000000')  
+m.plot(x2,y2, marker='.', markersize=8, color='#000000')  
+m.plot(x3,y3, marker='.', markersize=8, color='#000000')  
+
+# Of note, the map uses metres as it's smallest distance, so 1000*x is x km
+# The offset is in projection cooordinates
+plt.text(x1+100000,y1+100000,'Ottawa')
+plt.text(x2+100000,y2+100000,'Paris')
+plt.text(x3+100000,y3+100000,'Victoria')
+
+# Draw a great circle line joining them
+m.drawgreatcircle(lo1,la1,lo2,la2,linewidth=1,color='#000000',alpha=1,del_s=100)
+m.drawgreatcircle(lo2,la2,lo3,la3,linewidth=1,color='#000000',alpha=1,del_s=100)
+
+# Drawing a great circle which exits and reenters the map works on certain projections
+m.drawgreatcircle(lo1,la1,lo3,la3,linewidth=1,color='#FF0000',alpha=1,del_s=100)
+
+plt.show()