Minimal example: ``` import control import matplotlib.pyplot as pltimport control import matplotlib.pyplot as plt tf1 = control.tf([1],[1,1]) fig, ax = plt.subplots(1, 2) control.root_locus(tf1, ax=ax[0]) control.root_locus(tf1, ax=ax[1]) plt.show() ``` Produces:  Expected:  PR incoming :-)