% Problem 7.11
A=[ 0        1   0       0  0     0 
   -0.80435 -0.1 0.80435 0 48.261 0
    0        0   0       1  0     0
    1.6086   0  -1.6087  0  0     0
    0        0   0       0  0     1
    0        0.5 0       0  0    -2];

B=[0; 0; 0; 0; 0; 1];

C=[1 0 0 0 0 0];

D=0;

[num,den]=ss2tf(A,B,C,D,1);
for j=1:length(num),
    if abs(num(j))<1.e-10
       num(j)=0;
    end
end
for j=1:length(den),
    if abs(den(j))<1.e-10
       den(j)=0;
    end
end
printsys(num,den,'s')
[p,z]=pzmap(num,den)
rlocus(num,den)
axis([-3 3 -3 3])
grid
