%  Example 5.1.  Nyquist plot generation.
clear
%  Define the loop transfer fucntion.
nu=2;
de=[1 -1];
%  Generate and plot the nyquist locus.
set(0,'DefaultAxesFontName','times')
set(0,'DefaultAxesFontSize',16)
set(0,'DefaultTextFontName','times')
figure(1)
clf
[re,im]=nyquist(nu,de);
plot(re,im,'r-',re,-im,'r-',-1,0,'r+',re(47),im(47),...
   'r>',re(47),-im(47),'r<')
axis([-2 2 -2 2])
axis('square')
xlabel('Real axis')
ylabel('Imaginary axis')
grid
