import numpy as np
import control
import matplotlib.pyplot as plt

# L = control.TransferFunction((1), (1, 6, 5, 0, 0))
# L = control.TransferFunction((1, 2), (1, 10, 0, 0))
L = control.TransferFunction((1, 1), (1, -3, 0))

rlist, klist = control.rlocus(L, kvect=np.linspace(100, -100, num=1000))

plt.show()