from sympy.abc import a, b, c, d, e, f, s
from sympy.physics.control.lti import TransferFunction
from spb import *
tf = TransferFunction(a * s**2 + b * s + c, d**2 * s**2 + e * s + f, s)
params = {
    a: (2, 0, 10),
    b: (5, 0, 10),
    c: (1, 0, 10),
    d: (1, 0, 10),
    e: (2, 0, 10),
    f: (3, 0, 10),
}
graphics(
    nyquist(tf, params=params),
    xlabel="Real", ylabel="Imaginary",
    xlim=(-1, 4), ylim=(-2.5, 2.5), aspect="equal"
)