%24.13
%{
G1=tf(1,[1,0.5,1])
stepinfo(G1,'SettlingTimeThreshold',0.1)
impulse(G1)
G2=tf(1,[5,0.5,1])
stepinfo(G2,'SettlingTimeThreshold',0.1)
impulse(G2)
%}

%24.17 inte klar
%{
G1=tf(1,[1,2])
G2=tf(2,[1,3,2])
G3=tf(1,[0.2,1])

%R->Y
sys = series(G1,G2)
sys = feedback(sys,G3)

%sys2= feedback(G2,G1)

%}

%24.19
%{
G1=tf(2,[5,1]);
G2=tf(5,[6,2,0]);
G3=tf(3,[1,0.4,4]);
G4=tf(5,[1,1.2,4]);
[G1mag,G1phase] = bode(G1,0.5)
[G1mag,G1phase] = bode(G1,2.5)
[G2mag,G2phase] = bode(G2,0.5)
[G2mag,G2phase] = bode(G2,2.5)
[G3mag,G3phase] = bode(G3,0.5)
[G3mag,G3phase] = bode(G3,2.5)
[G4mag,G4phase] = bode(G4,0.5)
[G4mag,G4phase] = bode(G4,2.5)
%}

%24.21


%a
%{
G1=tf(8,[1,2]);
G2=tf(2,[1,3,2]);
G3=tf(1,[0.2,1]);


sys = series(G1,G2)
sys = series(sys,G3);
margin(sys)
[Gm,Pm,Wcg,Wcp] = margin(sys);
20*log10(Gm);


%step(sys)
%}
%b
%{
G1=tf(1,[1,2,0]);
G2=tf(2,[1,4,2]);
G3=tf(1);
sys = series(G1,G2)
sys = series(sys,G3);
[Gm,Pm,Wcg,Wcp] = margin(sys);
20*log10(Gm)


%}
%c
%{
G1=tf(1,[1,2,0]);
G2=tf(2,[1,4,2]);
G3=tf(1);
sys = series(G1,G2)
sys = feedback(sys,G3);

step(sys)
%}





%%
%24.22

s=conv([5,1],[2,1]);
s=conv(s,[1,1]);
G=tf(5,s);

%k=1.59385=>Pm=15
%k=0.574039=>Pm=60
%k=1.078046=>Pm=30
%k=0.768916=>Pm=45

bode(G)

for v=1.59385
b=b+1;
G=v*G;
%margin(G);
[Gm,Pm,Wcg,Wcp] = margin(G);
sys2=feedback(G,1);
%step(sys2)
end