SF.net SVN: matplotlib:[6977] trunk/toolkits/basemap

[<js...@us...>]

Revision: 6977
          http://matplotlib.svn.sourceforge.net/matplotlib/?rev=6977&view=rev
Author:   jswhit
Date:     2009-03-14 13:53:24 +0000 (Sat, 14 Mar 2009)

Log Message:
-----------
added shaded relief plot example.

Modified Paths:
--------------
    trunk/toolkits/basemap/Changelog
    trunk/toolkits/basemap/MANIFEST.in
    trunk/toolkits/basemap/examples/README

Added Paths:
-----------
    trunk/toolkits/basemap/examples/plotmap_shaded.py

Modified: trunk/toolkits/basemap/Changelog
===================================================================
--- trunk/toolkits/basemap/Changelog	2009-03-14 13:49:09 UTC (rev 6976)
+++ trunk/toolkits/basemap/Changelog	2009-03-14 13:53:24 UTC (rev 6977)
@@ -1,4 +1,5 @@
 version 0.99.4 (not yet released)
+           * added new example "plotmap_shaded.py" (shaded relief plot).
            * added new example "plothighsandlows.py".
            * add fix_aspect kwarg to Basemap.__init__, when False
              axes.set_aspect is set to 'auto' instead of default 'equal'.

Modified: trunk/toolkits/basemap/MANIFEST.in
===================================================================
--- trunk/toolkits/basemap/MANIFEST.in	2009-03-14 13:49:09 UTC (rev 6976)
+++ trunk/toolkits/basemap/MANIFEST.in	2009-03-14 13:53:24 UTC (rev 6977)
@@ -40,6 +40,7 @@
 include examples/plotmap.py
 include examples/plotmap_oo.py
 include examples/plotmap_masked.py
+include examples/plotmap_shaded.py
 include examples/contour_demo.py
 include examples/customticks.py
 include examples/quiver_demo.py

Modified: trunk/toolkits/basemap/examples/README
===================================================================
--- trunk/toolkits/basemap/examples/README	2009-03-14 13:49:09 UTC (rev 6976)
+++ trunk/toolkits/basemap/examples/README	2009-03-14 13:53:24 UTC (rev 6977)
@@ -20,6 +20,9 @@
 in test.py) which shows the ETOPO topography as an image on a Lambert
 Conformal projection (using imshow).
 
+plotmap_shaded.py shows how to make a 'shaded relief' plot by specifying
+the location of a lightsource.
+
 plotmap_oo.py is a version of plotmap.py that does not import pylab - it uses
 the matplotlib OO interface instead.
 

Added: trunk/toolkits/basemap/examples/plotmap_shaded.py
===================================================================
--- trunk/toolkits/basemap/examples/plotmap_shaded.py	                        (rev 0)
+++ trunk/toolkits/basemap/examples/plotmap_shaded.py	2009-03-14 13:53:24 UTC (rev 6977)
@@ -0,0 +1,48 @@
+# make shaded relief plot of etopo bathymetry/topography data on
+# lambert conformal conic map projection.
+
+# the data is interpolated to the native projection grid.
+
+from mpl_toolkits.basemap import Basemap, shiftgrid
+import numpy as np
+import matplotlib.pyplot as plt
+import matplotlib.mlab as mlab
+from matplotlib.colors import lightsource
+
+# read in topo data (on a regular lat/lon grid)
+# longitudes go from 20 to 380.
+topoin = mlab.load('etopo20data.gz')
+lons = mlab.load('etopo20lons.gz')
+lats = mlab.load('etopo20lats.gz')
+# shift data so lons go from -180 to 180 instead of 20 to 380.
+topoin,lons = shiftgrid(180.,topoin,lons,start=False)
+
+# setup of basemap ('lcc' = lambert conformal conic).
+# use major and minor sphere radii from WGS84 ellipsoid.
+m = Basemap(llcrnrlon=-145.5,llcrnrlat=1.,urcrnrlon=-2.566,urcrnrlat=46.352,\
+            rsphere=(6378137.00,6356752.3142),\
+            resolution='l',area_thresh=1000.,projection='lcc',\
+            lat_1=50.,lon_0=-107.)
+# transform to nx x ny regularly spaced native projection grid
+nx = int((m.xmax-m.xmin)/40000.)+1; ny = int((m.ymax-m.ymin)/40000.)+1
+topodat,x,y = m.transform_scalar(topoin,lons,lats,nx,ny,returnxy=True)
+ls = lightsource(azdeg = 90, altdeg = 20)
+print topodat.shape
+rgb = ls.shade(topodat, plt.cm.jet)
+# create the figure.
+fig=plt.figure(figsize=(8,8))
+# plot image over map with imshow.
+im = m.imshow(rgb)
+# draw coastlines and political boundaries.
+m.drawcoastlines()
+m.drawcountries()
+# draw parallels and meridians.
+# label on left, right and bottom of map.
+parallels = np.arange(0.,80,20.)
+m.drawparallels(parallels,labels=[1,1,0,1])
+meridians = np.arange(10.,360.,30.)
+m.drawmeridians(meridians,labels=[1,1,0,1])
+# set title.
+plt.title('ETOPO Shaded Relief - Lambert Conformal Conic')
+#plt.savefig('plotmap.pdf')
+plt.show()


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