A = [   -0.7   -0.0458     -12.2        0
           0    -0.014   -0.2904   -0.562
           1   -0.0057      -1.4        0
           1         0         0        0 ];
 
B = [  -19.1      -3.1
     -0.0119   -0.0096
       -0.14     -0.72
           0         0 ];
 
C = [      0         0        -1        1
           0         0     0.733        0 ];
 
D = [      0         0
      0.0768    0.1134 ];

sys = ss (A, B, C, D);

z = zero (sys)

% Expected Results from the "Dark Side"
%
%  -13.2759
%   12.5774
%   -0.0155
%

% Results from tzero.m
%
%   -5.708333
%   -0.015561
%   31.509741
