Fixed bug in EKF residual function.

Comment was wrong, it normalizes to [-pi, pi].

Also, code didn't handle cases where a-b > 2Pi

10-Unscented-Kalman-Filter.ipynb

@@ -3433,7 +3433,7 @@
    "source": [
     "def normalize_angle(x):\n",
     "    x = x % (2 * np.pi)    # force in range [0, 2 pi)\n",
-    "    if x > np.pi:          # move to [-pi, pi]\n",
+    "    if x > np.pi:          # move to [-pi, pi)\n",
     "        x -= 2 * np.pi\n",
     "    return x"
    ]

code/book_format.py

@@ -12,7 +12,7 @@ sys.path.insert(0,'./code') # allow us to import book_format
 
 def test_filterpy_version():
     import filterpy
-    min_version = [0,0,22]
+    min_version = [0,0,25]
     v = filterpy.__version__
     tokens = v.split('.')
     for i,v in enumerate(tokens):