Bode Plot vs Nyquist Plot vs Nichols Chart for Minimum Phase Systems in MATLAB

Minimum phase systems have all poles and zeros in the left-half s-plane. In MATLAB, plot stability margins using bode(), nyquist(), and margin():

% Define open-loop transfer function G(s)
G = tf([10], [1 4 5 0]);

figure;
margin(G); % Plots Bode diagram with GM and PM markers

figure;
nyquist(G); % Plots Nyquist stability locus

% Calculate numerical margins
[GM, PM, wcg, wcp] = margin(G);
fprintf('Gain Margin: %.2f dB\n', 20*log10(GM));
fprintf('Phase Margin: %.2f deg\n', PM);