sifunction中多维输入的问题?

gildon

我最近碰到一个这样的问题.在编写s-function时.一般都是输出是多维的..但如果输入也是多维的..应该怎么写呢?
比如说这个例题: y''(t)+25y'(t)=0.5r'(t)   程序如下:  高手帮看下哪里错了？
function [sys,x0,str,ts] = twoinput(t,x,u,flag)
A=[0 1
   0 -5];
B=[0  0
   0 0.1];
C=[1 0];
switch flag,
  case 0,
    [sys,x0,str,ts]=mdlInitializeSizes(A,B,C);
  case 1,
    sys=mdlDerivatives(t,x,u,A,B);

  case 2,
    sys=mdlUpdate(t,x,u);
  case 3,
    sys=mdlOutputs(t,x,u,C);
  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(A,B,C)
sizes = simsizes;
sizes.NumContStates  = 1;
sizes.NumDiscStates  = 0;
sizes.NumOutputs     = 1;
sizes.NumInputs      = 1;
sizes.DirFeedthrough = 1;
sizes.NumSampleTimes = 1;   % at least one sample time is needed
sys = simsizes(sizes);
x0  = [0];
str = [];% str is always an empty matrix
ts  = [0 0];% initialize the array of sample times
function sys=mdlDerivatives(t,x,u,A,B)
sys = A*x+B*u;

function sys=mdlUpdate(t,x,u)
sys = [];
function sys=mdlOutputs(t,x,u,C)
sys = C*x;
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 = [];
% end mdlTerminate

[ 本帖最后由 16443 于 2008-6-30 11:11 编辑 ]