from sympy.abc import s
from sympy.physics.control.lti import TransferFunction
from spb import *
tf1 = TransferFunction(
    1*s**2 + 0.1*s + 7.5, 1*s**4 + 0.12*s**3 + 9*s**2, s)
graphics(
    bode_phase(tf1, initial_exp=0.2, final_exp=0.7),
    xscale="log", xlabel="Frequency [rad/s]",
    ylabel="Magnitude [dB]"
)