Edit to fit on 6x9 book.

Somewhat arbitrary, but I want the code to be readable on
narrow paper than 8.5x11.

code/kf_internal.py

@@ -0,0 +1,34 @@
+# -*- coding: utf-8 -*-
+"""
+Created on Sat Jul 25 17:13:23 2015
+
+@author: rlabbe
+"""
+
+import book_plots as bp
+import matplotlib.pyplot as plt
+
+def plot_dog_track(xs, measurement_var, process_var):
+    N = len(xs)
+    bp.plot_track([0, N-1], [1, N])
+    bp.plot_measurements(xs, label='Sensor')
+    bp.set_labels('variance = {}, process variance = {}'.format(
+              measurement_var, process_var), 'time', 'pos')
+    plt.ylim([0, N])
+    bp.show_legend()
+    plt.show()
+
+
+def print_gh(predict, update, z):
+    predict_template = 'PREDICT: {: 6.2f} {: 6.2f}'
+    update_template = 'UPDATE: {: 6.2f} {: 6.2f}\tZ: {:.2f}'
+
+    print(predict_template.format(predict[0], predict[1]),end='\t')
+    print(update_template.format(update[0], update[1], z))
+
+
+def print_variance(positions):
+    print('Variance:')
+    for i in range(0, len(positions), 5):
+        print('\t{:.4f} {:.4f} {:.4f} {:.4f} {:.4f}'.format(
+                *[v[1] for v in positions[i:i+5]]))