%
% Nyquist Plot
%
% SEM 5928 - Sistemas de Controle 
% Escola de Engenharia de São Carlos - USP
%
% Adriano Siqueira - 2016
%
close all
G = tf(1,[1 1]);

%w = .1:.1:100;
w = logspace(-5,2,1000);

for i=1:length(w),

re(i) = 1/(1 + w(i)^2);

im(i) = - w(i)/(1 + w(i)^2);

Gw = re +j*im;

MGw = abs(Gw);

MGwdecibel = 20*log10(MGw);

FGw = angle(Gw);

FGwgraus = FGw*180/pi;

end

figure;plot(re,im);grid
axis([-1 1 -.5 .5])
figure;nyquist(G)