"""
    Appears to not provide a valid value for this transfer function.  Provides the return
    value "nand" instead.
"""

import matplotlib.pyplot as plt
import control as ct

Gc = ct.tf([6.67, 1], [66.7, 1])
Gs = ct.tf([20], [0.5, 1, 0])
sys_series = ct.series(Gs, Gc)
Ls = ct.tf(sys_series)

plt.style.use('dark_background') 

# Also tried passing in "Ls" as the argument to no avail
bw = ct.bandwidth(sys_series, dbdrop=-3)
print(bw)

plt.figure()
ct.nichols(Ls, grid=True)
plt.show()

"""
   Test with simpler transfer functions
"""
num1 = [1]; den1 = [1, 1]
sys1 = ct.tf(num1, den1)

# System 2 (Bandwidth ~10 rad/s)
num2 = [10]; den2 = [1, 10]
sys2 = ct.tf(num2, den2)

# System 3 (Bandwidth ~50 rad/s)
num3 = [50]; den3 = [1, 50]
sys3 = ct.tf(num3, den3)

# 2. Calculate the bandwidth for each system
bw1 = ct.bandwidth(sys1)
bw2 = ct.bandwidth(sys2)
bw3 = ct.bandwidth(sys3)

print(f"System 1 Bandwidth: {bw1:.2f} rad/s")
print(f"System 2 Bandwidth: {bw2:.2f} rad/s")
print(f"System 3 Bandwidth: {bw3:.2f} rad/s")

# Test with two simple functions in series - does work
sys4 = ct.series(sys1, sys2)
bw4 = ct.bandwidth(sys4)
print(f"System 4 Bandwidth: {bw4:.2f} rad/s")