function [sys,x0,str,ts] =obser3(t,x,u,flag)
switch flag,
case 0,
[sys,x0,str,ts]=mdlInitializeSizes;
case 1,
sys=mdlDerivatives(t,x,u);
case 3,
sys=mdlOutputs(t,x,u);
case {2,4,9}
sys=[];
otherwise
error(['Unhandled flag= ', num2str(flag)]);
end
function [sys,x0,str,ts]=mdlInitializeSizes
sizes = simsizes;
sizes.NumContStates = 2;
sizes.NumDiscStates = 0;
sizes.NumOutputs = 4;
sizes.NumInputs = 1;
sizes.DirFeedthrough = 0;
sizes.NumSampleTimes = 0;
sys = simsizes(sizes);
x0 = [0 0];
str = [];
ts = [];
function sys=mdlDerivatives (t,x,u)
ut=u(1);
fx=sin(x(1))*x(2)^2/(x(1)^2+1);
gx=2*x(1)^2+2;
sys(1)=x(2);
sys(2)=fx+gx*ut;
function sys=mdlOutputs(t,x,u)
fx=sin(x(1))*x(2)^2/(x(1)^2+1);
gx=2*x(1)^2+2;
sys(1)=x(1);
sys(2)=x(2);
sys(3)=fx;
sys(4)=gx;
