% mysos

% clear command window and variable memory
clc
clear

% define 2nd order system parameters
wn = .1;     % natural frequency
z = .1;      % damping constant

% step response
n = [wn^2];
d = [1 2*z*wn wn^2];
g = tf(n, d);
step (g)

% pause for the user
display ('Hit Enter to continue');
pause
figure    % create new plot window

% frequency response
w = 0 : wn/10 : 5*wn;
gjw = freqs(n, d, w);
gmag = abs (gjw);
plot (w, gmag);
% alternative method:
%gjw = freqresp (g, w);
%gmag = abs (gjw);
%[m n] = size(w);
%i = 1 : n;
%yw(i) = gmag (1, 1, i);
%plot (w, yw);

% pause for the user
display ('Hit Enter to continue');
pause

% remove figures
close all
clc