fix bug in drawlsmask

Changelog

@@ -1,5 +1,6 @@
 version 1.0.5 (git tag v1.0.5rel)
 ---------------------------------
+* fix bug triggered when drawlsmask method called more than once.
 * fix error in contour method that caused a bogus mask to be applied
   to the data (issue 58).
 * fix further corner cases with splitting of parallels that cross

examples/wiki_example.py

@@ -4,25 +4,25 @@
 # set up orthographic map projection with
 # perspective of satellite looking down at 50N, 100W.
 # use low resolution coastlines.
-map = Basemap(projection='ortho',lat_0=45,lon_0=-100,resolution='l')
+bmap = Basemap(projection='ortho',lat_0=45,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',lake_color='aqua')
+bmap.drawcoastlines(linewidth=0.25)
+bmap.drawcountries(linewidth=0.25)
+bmap.fillcontinents(color='coral',lake_color='aqua')
 # draw the edge of the map projection region (the projection limb)
-map.drawmapboundary(fill_color='aqua')
+bmap.drawmapboundary(fill_color='aqua')
 # draw lat/lon grid lines every 30 degrees.
-map.drawmeridians(np.arange(0,360,30))
-map.drawparallels(np.arange(-90,90,30))
+bmap.drawmeridians(np.arange(0,360,30))
+bmap.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)
+xc,yc = bmap(lons,lats)
 # plot filled circles at the locations of the cities.
-map.plot(xc,yc,'bo')
+bmap.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)
@@ -33,69 +33,87 @@
 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)
+x, y = bmap(lons*180./np.pi, lats*180./np.pi)
 # contour data over the map.
-cs = map.contour(x,y,wave+mean,15,linewidths=1.5)
+cs = bmap.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))
+bmap.drawmapboundary()
+bmap.drawmeridians(np.arange(0,360,30))
+bmap.drawparallels(np.arange(-90,90,30))
 # plot filled circles at the locations of the cities.
-map.plot(xc,yc,'wo')
+bmap.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)
+cs = bmap.contour(x,y,wave+mean,15,linewidths=1.5)
 plt.title('land-sea mask background')
-map.drawlsmask(ocean_color='aqua',land_color='coral')
+bmap.drawlsmask(ocean_color='aqua',land_color='coral')
 
 # 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))
+bmap.drawmapboundary()
+bmap.drawmeridians(np.arange(0,360,30))
+bmap.drawparallels(np.arange(-90,90,30))
 # plot filled circles at the locations of the cities.
-map.plot(xc,yc,'wo')
+bmap.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)
+cs = bmap.contour(x,y,wave+mean,15,linewidths=1.5)
 plt.title('blue marble background')
-map.bluemarble()
+bmap.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))
+bmap.drawmapboundary()
+bmap.drawmeridians(np.arange(0,360,30))
+bmap.drawparallels(np.arange(-90,90,30))
 # plot filled circles at the locations of the cities.
-map.plot(xc,yc,'wo')
+bmap.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)
+cs = bmap.contour(x,y,wave+mean,15,linewidths=1.5)
 plt.title('shaded relief background')
-map.shadedrelief()
+bmap.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))
+bmap.drawmapboundary()
+bmap.drawmeridians(np.arange(0,360,30))
+bmap.drawparallels(np.arange(-90,90,30))
 # plot filled circles at the locations of the cities.
-map.plot(xc,yc,'wo')
+bmap.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)
+cs = bmap.contour(x,y,wave+mean,15,linewidths=1.5)
 plt.title('etopo background')
-map.etopo()
+bmap.etopo()
+
+# as above, but use etopo image as map background overlaid with
+# land-sea mask image where land areas are transparent (so etopo
+# image shows through over land).
+fig = plt.figure()
+bmap.drawmapboundary()
+bmap.drawmeridians(np.arange(0,360,30))
+bmap.drawparallels(np.arange(-90,90,30))
+# plot filled circles at the locations of the cities.
+bmap.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 = bmap.contour(x,y,wave+mean,15,linewidths=1.5)
+plt.title('etopo background with oceans masked')
+bmap.etopo()
+bmap.drawlsmask(ocean_color='DarkBlue',land_color=(255,255,255,1))
 
 plt.show()

lib/mpl_toolkits/basemap/__init__.py

@@ -3679,14 +3679,14 @@ def drawlsmask(self,land_color="0.8",ocean_color="w",lsmask=None,
                     mask[j,:]=np.where(np.logical_or(xx<xmin[j],xx>xmax[j]),\
                                         255,mask[j,:])
             self.lsmask = mask
-        ny, nx = mask.shape
+        ny, nx = self.lsmask.shape
         rgba = np.ones((ny,nx,4),np.uint8)
         rgba_land = np.array(rgba_land,np.uint8)
         rgba_ocean = np.array(rgba_ocean,np.uint8)
         for k in range(4):
-            rgba[:,:,k] = np.where(mask,rgba_land[k],rgba_ocean[k])
+            rgba[:,:,k] = np.where(self.lsmask,rgba_land[k],rgba_ocean[k])
         # make points outside projection limb transparent.
-        rgba[:,:,3] = np.where(mask==255,0,rgba[:,:,3])
+        rgba[:,:,3] = np.where(self.lsmask==255,0,rgba[:,:,3])
         # plot mask as rgba image.
         im = self.imshow(rgba,interpolation='nearest',ax=ax,**kwargs)
         # clip for round polar plots.