Cleaning up example mplot3d/bars3d_demo

TrishGillett · TrishGillett · commit cc9e1bd5ef61 · 2016-04-14T14:17:49.000-04:00
diff --git a/examples/mplot3d/bars3d_demo.py b/examples/mplot3d/bars3d_demo.py
@@ -1,21 +1,35 @@
+'''
+Demonstrates making a 3D plot which has 2D bar graphs projected onto
+planes y=0, y=1, etc.
+'''
+
 from mpl_toolkits.mplot3d import Axes3D
 import matplotlib.pyplot as plt
 import numpy as np
 
 fig = plt.figure()
 ax = fig.add_subplot(111, projection='3d')
-for c, z in zip(['r', 'g', 'b', 'y'], [30, 20, 10, 0]):
+
+colors = ['r', 'g', 'b', 'y']
+yticks = [3, 2, 1, 0]
+for c, k in zip(colors, yticks):
+    # Generate the random data for the y=k 'layer'.
     xs = np.arange(20)
     ys = np.random.rand(20)
 
-    # You can provide either a single color or an array. To demonstrate this,
-    # the first bar of each set will be colored cyan.
+    # You can provide either a single color or an array with the same length as
+    # xs and ys. To demonstrate this, we color the first bar of each set cyan.
     cs = [c] * len(xs)
     cs[0] = 'c'
-    ax.bar(xs, ys, zs=z, zdir='y', color=cs, alpha=0.8)
+
+    # Plot the bar graph given by xs and ys on the plane y=k with 80% opacity.
+    ax.bar(xs, ys, zs=k, zdir='y', color=cs, alpha=0.8)
 
 ax.set_xlabel('X')
 ax.set_ylabel('Y')
 ax.set_zlabel('Z')
 
+# On the y axis let's only label the discrete values that we have data for.
+ax.set_yticks(yticks)
+
 plt.show()
