@@ -0,0 +1,46 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+"""sisotooldemo.py
+
+Shows some different systems with sisotool. 
+
+All should produce smooth root-locus plots, also zoomable and clickable, 
+with proper branching
+"""
+
+#%%
+import matplotlib.pyplot as plt
+from control.matlab import *
+
+# first example, aircraft attitude equation
+s = tf([1,0],[1])
+Kq = -24
+T2 = 1.4
+damping = 2/(13**.5)
+omega = 13**.5
+H = (Kq*(1+T2*s))/(s*(s**2+2*damping*omega*s+omega**2))
+plt.close('all')
+sisotool(-H)
+
+#%%
+
+# a simple RL, with multiple poles in the origin
+plt.close('all')
+H = (s+0.3)/(s**4 + 4*s**3 + 6.25*s**2)
+sisotool(H)
+
+#%%
+
+# a branching and emanating example
+b0 = 0.2
+b1 = 0.1
+b2 = 0.5
+a0 = 2.3
+a1 = 6.3
+a2 = 3.6
+a3 = 1.0
+
+plt.close('all')
+H = (b0 + b1*s + b2*s**2) / (a0 + a1*s + a2*s**2 + a3*s**3)
+
+sisotool(H)