User`s guide

3 Writing S-Functions As C-MEX files
3-64
/* Function: mdlOutputs =======================================================
* Abstract:
* y = Cx + Du
*/
static void mdlOutputs(SimStruct *S, int_T tid)
{
real_T *y = ssGetOutputPortRealSignal(S,0);
real_T *x = ssGetRealDiscStates(S);
InputRealPtrsType uPtrs = ssGetInputPortRealSignalPtrs(S,0);
/* y=Cx+Du */
y[0]=C[0][0]*x[0]+C[0][1]*x[1]+D[0][0]*U(0)+D[0][1]*U(1);
y[1]=C[1][0]*x[0]+C[1][1]*x[1]+D[1][0]*U(0)+D[1][1]*U(1);
}
#define MDL_UPDATE
/* Function: mdlUpdate ======================================================
* Abstract:
* xdot = Ax + Bu
*/
static void mdlUpdate(SimStruct *S, int_T tid)
{
real_T tempX[2] = {0.0, 0.0};
real_T *x = ssGetRealDiscStates(S);
InputRealPtrsType uPtrs = ssGetInputPortRealSignalPtrs(S,0);
/* xdot=Ax+Bu */
tempX[0]=A[0][0]*x[0]+A[0][1]*x[1]+B[0][0]*U(0)+B[0][1]*U(1);
tempX[1]=A[1][0]*x[0]+A[1][1]*x[1]+B[1][0]*U(0)+B[1][1]*U(1);
x[0]=tempX[0];
x[1]=tempX[1];
}
/* Function: mdlTerminate =====================================================
* Abstract:
* No termination needed, but we are required to have this routine.
*/
static void mdlTerminate(SimStruct *S)
{
}
#ifdef MATLAB_MEX_FILE /* Is this file being compiled as a MEX-file? */
#include "simulink.c" /* MEX-file interface mechanism */
#else
#include "cg_sfun.h" /* Code generation registration function */
#endif