%S-function for continuous state equation
function [sys,x0,str,ts]=s_function(t,x,u,flag)

switch flag,
%Initialization
  case 0,
    [sys,x0,str,ts]=mdlInitializeSizes;
case 1,
    sys=mdlDerivatives(t,x,u);
%Outputs
  case 3,
    sys=mdlOutputs(t,x,u);
%Unhandled flags
  case {2, 4, 9 }
    sys = [];
%Unexpected flags
  otherwise
    error(['Unhandled flag = ',num2str(flag)]);
end

%mdlInitializeSizes
function [sys,x0,str,ts]=mdlInitializeSizes
sizes = simsizes;
sizes.NumContStates  = 2;
sizes.NumDiscStates  = 0;
sizes.NumOutputs     = 1;
sizes.NumInputs      = 1;
sizes.DirFeedthrough = 0;
sizes.NumSampleTimes = 0;

sys=simsizes(sizes);
x0=[0,0];
str=[];
ts=[];

function sys=mdlDerivatives(t,x,u)
A=[0 1;2 3];
B=[0;10];

sys(1)=x(2);
sys(2)=A(2,1)*x(1)+A(2,2)*x(2)+B(2)*(u+sin(2*pi*t));
function sys=mdlOutputs(t,x,u)
sys(1)=x(1);