% PIPE FLOW SETUP 
% OPEN LOOP PLOT 

clear all
X=0.25;Y=1.0;Z=1.0;
A=0.1;B=1.0;T=0.5;
GP=1.5;GI=0.0;GD=0.0;
W=0.05;DW=0.25;
NIT=500;
for K=1:NIT
S=complex(0.0,W);
PID=GD*S+GP+GI/S;
num=PID*Z*exp(-T*S);
den=(X*S+Y)*(A*S+B);
p(K)=real(num/den);
q(K)=imag(num/den);
W=W+DW;
end
plot(p,q,p,-q);
title('lab gh plot')
xlabel('real')
ylabel('imag')
grid