WT = 0.4*s/(s + 1); w = logspace(-2, 2, 200); % omega WT_jw = frd(WT, w); % frequency response P0_jw = frd(P0, w); figure(3); bodemag(WT_jw, 'r'); hold on; for c=0.8:0.05:1.2 Ptilde = 1/((s-1)*(c*s + 1)); Ptilde_jw = frd(Ptilde, w); bodemag(Ptilde_jw/P0_jw - 1, 'b'); end legh = legend('$W_T$', '$\Delta$', 'Location', 'SouthEast'); set(legh, 'interpreter', 'latex'); for phi=0:30:360 Delta_jw = exp(1i*phi*pi/180); P_jw = P0_jw * (1 + WT_jw * Delta_jw); figure(1); bode(P_jw, 'g'); end