s=%s;
t=0:0.15:5;
k=2;
T1=0.5;
T2=0.42;
T3=0.25;
F=k/((T1*s+1)*(T2*s+1)*(T3*s+1));
F1=syslin('c',F);
y1=csim('step',t,F1);
y2=csim('impulse',t,F1);
figure(0);
clf;
plot(t,y1)
figure(1);
clf;
plot(t,y2)
figure(2);
clf;
bode(F1)
figure(3);
nyquist(F1)
figure(4);
black(F1)
figure(5);
show_margins(F1)

G=(s*T1+1)/(T1*(s+1/T1));
G1=syslin('c',G);
y3=csim('step',t,G1);
y4=csim('impulse',t,G1);
figure(6);
clf;
plot(t,y3)
figure(7);
clf;
plot(t,y4)
figure(8);
clf;
bode(G1)
figure(9);
nyquist(G1)
figure(10);
black(G1)
figure(11);
show_margins(G1)