from sympy.abc import a, b, c, d, s
from sympy.physics.control.lti import TransferFunction
from spb import plot_pole_zero
tf1 = TransferFunction(s**2 + 1, s**4 + 4*s**3 + 6*s**2 + 5*s + 2, s)
tf2 = TransferFunction(s**2 + b, s**4 + a*s**3 + b*s**2 + c*s + d, s)
plot_pole_zero(
    (tf1, "A"), (tf2, "B"),
    params={
        a: (3, 0, 5),
        b: (5, 0, 10),
        c: (4, 0, 8),
        d: (3, 0, 5),
    },
    xlim=(-4, 1), ylim=(-4, 4),
    show_axes=True)