Theory :
Bode computes the magnitude and phase of the frequency response of LTI models. When invoked without left-side arguments, bode produces a Bode plot on the screen.
The magnitude is plotted in decibels (dB), and the phase in degrees.
The decibel calculation for magnitude is computed as 20log10 (|H(jw)|), where H(jw) is the system's frequency response.
Bode plots are used to analyze system properties such as the gain margin, phase margin, DC gain, bandwidth, disturbance rejection, and stability.