add etopo1 method

Author: Jeff Whitaker

Changelog

@@ -1,5 +1,7 @@
 version 1.0.2 (not yet released)
 	   * change default land-sea mask (now 2.5 minute resolution).
+           * add etopo method (similar to bluemarble, but plots etopo 
+             relief image from www.ngdc.noaa.gov/mgg/global as a map background).
            * add shadedrelief method (similar to bluemarble, but plots shaded
              relief image from naturalearthdata.com as a map background).
            * replace pyshapelib with pure python shapelib.py from

examples/wiki_example.py

@@ -36,6 +36,22 @@
 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)
+plt.title('filled continent background')
+
+# as above, but use land-sea mask 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)
+plt.title('land-sea mask background')
+map.drawlsmask(ocean_color='aqua',land_color='coral')
 
 # as above, but use blue marble image as map background.
 fig = plt.figure()
@@ -49,6 +65,37 @@
     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 shaded relief image in background.
+plt.title('blue marble background')
+map.bluemarble()
+
+# as above, but use shaded relief 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)
+plt.title('shaded relief background')
 map.shadedrelief()
+
+# as above, but use etopo 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)
+plt.title('etopo background')
+map.etopo()
+
 plt.show()

lib/mpl_toolkits/basemap/__init__.py

@@ -3309,6 +3309,24 @@ def shadedrelief(self,ax=None,scale=None,**kwargs):
         else:
             return self.warpimage(image='shadedrelief',scale=scale,**kwargs)
 
+    def etopo(self,ax=None,scale=None,**kwargs):
+        """
+        display etopo relief image (from
+        http://www.ngdc.noaa.gov/mgg/global/global.html)
+        as map background.
+        Default image size is 5400x2700, which can be quite slow and
+        use quite a bit of memory.  The ``scale`` keyword can be used
+        to downsample the image (``scale=0.5`` downsamples to 5400x2700).
+
+        \**kwargs passed on to :meth:`imshow`.
+
+        returns a matplotlib.image.AxesImage instance.
+        """
+        if ax is not None:
+            return self.warpimage(image='etopo',ax=ax,scale=scale,**kwargs)
+        else:
+            return self.warpimage(image='etopo',scale=scale,**kwargs)
+
     def warpimage(self,image="bluemarble",scale=None,**kwargs):
         """
         Display an image (filename given by ``image`` keyword) as a map background.
@@ -3343,10 +3361,14 @@ def warpimage(self,image="bluemarble",scale=None,**kwargs):
         # from NASA (http://visibleearth.nasa.gov).
         if image == "bluemarble":
             file = os.path.join(basemap_datadir,'bmng.jpg')
-        # display shadedrelief image (from
-        # http://www.ngdc.noaa.gov/mgg/image/globalimages.html)
+        # display shaded relief image (from
+        # http://www.shadedreliefdata.com)
         elif image == "shadedrelief":
             file = os.path.join(basemap_datadir,'shadedrelief.jpg')
+        # display etopo image (from
+        # http://www.ngdc.noaa.gov/mgg/image/globalimages.html)
+        elif image == "etopo":
+            file = os.path.join(basemap_datadir,'etopo1.jpg')
         else:
             file = image
         # if image is same as previous invocation, used cached data.