Clean up and move streamplot demos

tonysyu · tonysyu · commit a97d05840368 · 2013-04-18T20:58:06.000-05:00
diff --git a/doc/users/whats_new.rst b/doc/users/whats_new.rst
@@ -295,7 +295,7 @@ In addition to simply plotting the streamlines of the vector field,
 line widths of the streamlines to a separate parameter, such as the speed or
 local intensity of the vector field.
 
-.. plot:: mpl_examples/pylab_examples/streamplot_demo.py
+.. plot:: mpl_examples/images_contours_and_fields/streamplot_demo_features.py
 
 
 New hist functionality
diff --git a/examples/images_contours_and_fields/streamplot_demo_features.py b/examples/images_contours_and_fields/streamplot_demo_features.py
@@ -1,3 +1,13 @@
+"""
+Demo of the `streamplot` function.
+
+A streamplot, or streamline plot, is used to display 2D vector fields. This
+example shows a few features of the stream plot function:
+
+    * Varying the color along a streamline.
+    * Varying the density of streamlines.
+    * Varying the line width along a stream line.
+"""
 import numpy as np
 import matplotlib.pyplot as plt
 
diff --git a/examples/images_contours_and_fields/streamplot_demo_masking.py b/examples/images_contours_and_fields/streamplot_demo_masking.py
@@ -1,6 +1,8 @@
 """
-Demonstrate the use of the `streamplot` function using a masked array
-and NaN values.
+Demo of the streamplot function with masking.
+
+This example shows how streamlines created by the streamplot function skips
+masked regions and NaN values.
 """
 import numpy as np
 import matplotlib.pyplot as plt
@@ -17,7 +19,9 @@
 U[:20, :20] = np.nan
 
 plt.streamplot(X, Y, U, V, color='r')
-plt.imshow(~mask, extent=(-w, w, -w, w), alpha=0.5, interpolation='nearest')
+
+plt.imshow(~mask, extent=(-w, w, -w, w), alpha=0.5,
+           interpolation='nearest', cmap=plt.cm.gray)
 
 plt.show()
 
