如何在用M文件编写的s函数中定义一个向量变量啊？

zxhbuaa

我用M文件编写的s函数，想定义一个向量变量用于存储数据，可是总是提示我说变量未定义，这是怎么回事啊？那位给看看，多谢了。
function [sys,x0,str,ts] = para(t,x,u,flag,w,r)
W(1:1:64)=0;
r(1:1:64)=0;
mo=0.033;
switch flag,
    case 0,
    [sys,x0,str,ts]=mdlInitializeSizes;
   case 1,
    sys=mdlDerivatives(t,x,u);
   case 2,
    sys=mdlUpdate(t,x,u);
   case 3,
    sys=mdlOutputs(t,x,u);
   case 4,
    sys=mdlGetTimeOfNextVarHit(t,x,u);
   case 9,
    sys=mdlTerminate(t,x,u);
    otherwise
    error(['Unhandled flag = ',num2str(flag)]);
end
function [sys,x0,str,ts]=mdlInitializeSizes
sizes = simsizes;
sizes.NumContStates  = 0;
sizes.NumDiscStates  = 2;
sizes.NumOutputs     = 3;
sizes.NumInputs      = 2;
sizes.DirFeedthrough = 1;
sizes.NumSampleTimes = 1;   
sys = simsizes(sizes);

x0  = [0 0 ];
str = [];
ts  = [0.001 0];
function sys=mdlDerivatives(t,x,u)
sys = [];
function sys=mdlUpdate(t,x,u,w,r)
sys(1) = u(1)-u(2);
sys(2)=x(2)+2*0.033*sys(1)*u(1);
for i=1:1:64
    r(i)=r(i+1);
    r(i+1)=u(1);
    w(i)=w(i+1);
    w(i+1)=sys(2);      
end
function sys=mdlOutputs(t,x,u,w,r)
sys(1)=u(1);
sys(2)=u(1)-u(2);
sys(3)=u(1)*x(1);
   
function sys=mdlGetTimeOfNextVarHit(t,x,u)
sampleTime = 1;    %  Example, set the next hit to be one second later.
sys = t + sampleTime;
function sys=mdlTerminate(t,x,u)
sys = [];

zxhbuaa

找到错误了，多谢了