diverging colormaps with centered norms

endolith · endolith · commit 2df660994088 · 2012-06-05T13:01:18.000-04:00
diff --git a/examples/pylab_examples/griddata_demo.py b/examples/pylab_examples/griddata_demo.py
@@ -16,7 +16,7 @@
 zi = griddata(x,y,z,xi,yi,interp='linear')
 # contour the gridded data, plotting dots at the nonuniform data points.
 CS = plt.contour(xi,yi,zi,15,linewidths=0.5,colors='k')
-CS = plt.contourf(xi,yi,zi,15,cmap=plt.cm.jet)
+CS = plt.contourf(xi,yi,zi,15,cmap=plt.cm.rainbow, vmax=abs(zi).max(), vmin=-abs(zi).max())
 plt.colorbar() # draw colorbar
 # plot data points.
 plt.scatter(x,y,marker='o',c='b',s=5,zorder=10)
diff --git a/examples/pylab_examples/hexbin_demo2.py b/examples/pylab_examples/hexbin_demo2.py
@@ -39,14 +39,14 @@
 gridsize=30
 
 plt.subplot(211)
-plt.hexbin(x,y, C=z, gridsize=gridsize, marginals=True)
+plt.hexbin(x,y, C=z, gridsize=gridsize, marginals=True, cmap=cm.RdBu, vmax=abs(z).max(), vmin=-abs(z).max()) # NEEDS NORM
 plt.axis([xmin, xmax, ymin, ymax])
 cb = plt.colorbar()
 cb.set_label('mean value')
 
 
 plt.subplot(212)
-plt.hexbin(x,y, gridsize=gridsize)
+plt.hexbin(x,y, gridsize=gridsize, cmap=cm.Blues_r)
 plt.axis([xmin, xmax, ymin, ymax])
 cb = plt.colorbar()
 cb.set_label('N observations')
diff --git a/examples/pylab_examples/image_demo.py b/examples/pylab_examples/image_demo.py
@@ -11,8 +11,9 @@
 Z2 = mlab.bivariate_normal(X, Y, 1.5, 0.5, 1, 1)
 Z = Z2-Z1  # difference of Gaussians
 
-im = plt.imshow(Z, interpolation='bilinear', cmap=cm.gray,
-                origin='lower', extent=[-3,3,-3,3])
+im = plt.imshow(Z, interpolation='bilinear', cmap=cm.RdYlGn,
+                origin='lower', extent=[-3,3,-3,3],
+                vmax=abs(Z).max(), vmin=-abs(Z).max())
 
 plt.show()
 
diff --git a/examples/pylab_examples/pcolor_demo.py b/examples/pylab_examples/pcolor_demo.py
@@ -19,7 +19,7 @@ def func3(x,y):
 X,Y = meshgrid(x, y)
 
 Z = func3(X, Y)
-pcolor(X, Y, Z)
+pcolor(X, Y, Z, cmap=cm.RdBu, vmax=abs(Z).max(), vmin=-abs(Z).max())
 colorbar()
 axis([-3,3,-3,3])
 
diff --git a/examples/pylab_examples/pcolor_demo2.py b/examples/pylab_examples/pcolor_demo2.py
@@ -20,7 +20,7 @@ def func3(x,y):
 
 
 ax = subplot(111)
-im = imshow(Z, cmap=cm.jet)
+im = imshow(Z, cmap=cm.RdBu, vmax=abs(Z).max(), vmin=-abs(Z).max())
 #im.set_interpolation('nearest')
 #im.set_interpolation('bicubic')
 im.set_interpolation('bilinear')
diff --git a/examples/pylab_examples/poormans_contour.py b/examples/pylab_examples/poormans_contour.py
@@ -18,9 +18,9 @@
 Z2 = bivariate_normal(X, Y, 1.5, 0.5, 1, 1)
 Z = Z2 - Z1 # difference of Gaussians
 
-cmap = cm.get_cmap('jet', 10)    # 10 discrete colors
-
-im = imshow(Z, cmap=cmap, interpolation='bilinear')
+cmap = cm.get_cmap('PiYG', 11)    # 11 discrete colors
+#NORM
+im = imshow(Z, cmap=cmap, interpolation='bilinear', vmax=abs(Z).max(), vmin=-abs(Z).max())
 axis('off')
 colorbar()
 
