added various root_locus plotting examples

philn128 · philn128 · commit 3d57885423db · 2020-02-23T11:15:58.000-07:00
diff --git a/examples/root_locus.py b/examples/root_locus.py
@@ -0,0 +1,30 @@
+#!/usr/bin/env python
+import control as ct
+# from control.rlocus import root_locus
+import numpy as np
+import matplotlib.pyplot as plt
+import sys
+
+# create a transfer function
+gs_tf=ct.tf([1,10,5],[1,0,0])
+
+kvect=np.linspace(0,1.5,1000)
+
+rlist,klist=ct.root_locus(gs_tf,kvect=None,plot=True)
+plt.title("None")
+plt.show()
+
+# root locus plot
+rlist,klist=ct.root_locus(gs_tf,kvect=kvect,plot=True)
+plt.title("kvect")
+plt.legend(loc='best')
+plt.show()
+
+# calculate the root locus for matplotlib plot
+rlist,klist=ct.root_locus(gs_tf,kvect=kvect,Plot=False)
+
+# matplotlib plot
+plt.title("matplotlib")
+for index in range(len(rlist[0])):
+	plt.plot(np.real(rlist[:,index]),np.imag(rlist[:,index]))
+plt.show()
