[Matlab] C_MEX_S学习总结

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#define S_FUNCTION_NAME  Fcn  //这里把文件名修改为Fcn
#define S_FUNCTION_LEVEL 2
#define INPUT_NUM n	 //输入端口的数量
#define OUTPUT_NUM n  //输出端口的数量
#include "simstruc.h"
#include <math.h>
//定义 变量和函数如：
double  Ts;
double  para1,para2;

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A = *(mxGetPr(ssGetSFcnParam(S,0)));
B = *(mxGetPr(ssGetSFcnParam(S,1)));

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 double *para = ssGetRealDiscStates(S);
      para[0] = A ;
      para[1] = B;

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#define S_FUNCTION_NAME  Fcn //这里把文件名Fcn
#define S_FUNCTION_LEVEL 2
#define INPUT_NUM 1
#define OUTPUT_NUM 1

/*
 * Need to include simstruc.h for the definition of the SimStruct and
 * its associated macro definitions.
 */
 
#include "simstruc.h"
#include <math.h>


//定义 变量和函数如：
double  C;
double A,B;


/*====================*
 * S-function methods *
 *====================*/

/* Function: mdlInitializeSizes ===============================================
 * Abstract:
 *    The sizes information is used by Simulink to determine the S-function
 *    block's characteristics (number of inputs, outputs, states, etc.).
 */

static void mdlInitializeSizes(SimStruct *S)
{
    //这个函数用来设置输入、输出和参数的
    
    ssSetNumSFcnParams(S, 3);  /* 设置参数个数，这里为3 */
    if (ssGetNumSFcnParams(S) != ssGetSFcnParamsCount(S)) {
        /* Return if number of expected != number of actual parameters */
        return;
    }

    ssSetNumContStates(S,0);     //设置连续状态的个数，缺省为0
    ssSetNumDiscStates(S, 3);     //设置离散状态的个数，缺省为0；

    if (!ssSetNumInputPorts(S, INPUT_NUM)) return;   //设置输入变量的个数，这里为1
    ssSetInputPortWidth(S, 0, 2);                //设置输入变量0的维数为2
    ssSetInputPortRequiredContiguous(S, 0, true);   //设置input0的访问方式，true就是临近访问，这样指针的增量后就可以直接访问下个input端口了

    
    /*
     * Set direct feedthrough flag (1=yes, 0=no).
     * A port has direct feedthrough if the input is used in either
     * the mdlOutputs or mdlGetTimeOfNextVarHit functions.
     */
     
    ssSetInputPortDirectFeedThrough(S, 0, 1);       // 设置输入端口的信号是否mdlOutputs函数中使用，这儿设置为true。

    
    if (!ssSetNumOutputPorts(S, OUTPUT_NUM)) return;   //设置输出变量的个数，这里输出变量的个数为1
  ssSetOutputPortWidth(S, 0, 2); 

    
    ssSetNumSampleTimes(S, 1);      //设置采样个数，此处为1s。

    /* Specify the sim state compliance to be same as a built-in block */
    ssSetSimStateCompliance(S, USE_DEFAULT_SIM_STATE);

    ssSetOptions(S, 0);
}



/* Function: mdlInitializeSampleTimes =========================================
 * Abstract:
 *    This function is used to specify the sample time(s) for your
 *    S-function. You must register the same number of sample times as
 *    specified in ssSetNumSampleTimes.
 */
static void mdlInitializeSampleTimes(SimStruct *S)      
{
    ssSetSampleTime(S, 0, CONTINUOUS_SAMPLE_TIME);//继承系统采样时间
    ssSetOffsetTime(S, 0, 0.0);

}



#define MDL_INITIALIZE_CONDITIONS   /* Change to #undef to remove function */
#if defined(MDL_INITIALIZE_CONDITIONS)
  /* Function: mdlInitializeConditions ========================================
   * Abstract:
   *    In this function, you should initialize the continuous and discrete
   *    states for your S-function block.  The initial states are placed
   *    in the state vector, ssGetContStates(S) or ssGetRealDiscStates(S).
   *    You can also perform any other initialization activities that your
   *    S-function may require. Note, this routine will be called at the
   *    start of simulation and if it is present in an enabled subsystem
   *    configured to reset states, it will be call when the enabled subsystem
   *    restarts execution to reset the states.
   */
  static void mdlInitializeConditions(SimStruct *S)
  {
      double *para = ssGetRealDiscStates(S);
      para[0] = A + 1;
      para[1] = B + 2;
      para[2] = C;
  }
#endif /* MDL_INITIALIZE_CONDITIONS */



#define MDL_START  /* Change to #undef to remove function */
#if defined(MDL_START) 
  /* Function: mdlStart =======================================================
   * Abstract:
   *    This function is called once at start of model execution. If you
   *    have states that should be initialized once, this is the place
   *    to do it.
   */
  static void mdlStart(SimStruct *S)
  {
      A = *(mxGetPr(ssGetSFcnParam(S,0)));
      B = *(mxGetPr(ssGetSFcnParam(S,1)));
      C = *(mxGetPr(ssGetSFcnParam(S,2)));
  }
#endif /*  MDL_START */

  
//这里填入相关的运算、算法等
/* Function: mdlOutputs =======================================================
 * Abstract:
 *    In this function, you compute the outputs of your S-function
 *    block.
 */
static void mdlOutputs(SimStruct *S, int_T tid)  
//这里填入相关的运算、算法等
{
     double *para = ssGetRealDiscStates(S);
     const double *u = (const double*) ssGetInputPortSignal(S,0);
     double *y = ssGetOutputPortSignal(S,0); 
     
     A = para[0]; 
     B = para[1]
     y[0] = A*u[0]+5;
     y[1] = B*u[1]+3;
 
}

#define MDL_UPDATE  /* Change to #undef to remove function */
#if defined(MDL_UPDATE)
  /* Function: mdlUpdate ======================================================
   * Abstract:
   *    This function is called once for every major integration time step.
   *    Discrete states are typically updated here, but this function is useful
   *    for performing any tasks that should only take place once per
   *    integration step.
   */
  static void mdlUpdate(SimStruct *S, int_T tid)
  {
      double *para = ssGetRealDiscStates(S);
      para[0] = A;
      para[1] = B;
      para[2] = C;
  }
#endif /* MDL_UPDATE */



#define MDL_DERIVATIVES  /* Change to #undef to remove function */
#if defined(MDL_DERIVATIVES)
  /* Function: mdlDerivatives =================================================
   * Abstract:
   *    In this function, you compute the S-function block's derivatives.
   *    The derivatives are placed in the derivative vector, ssGetdX(S).
   */
  static void mdlDerivatives(SimStruct *S)
  {
  }
#endif /* MDL_DERIVATIVES */



/* Function: mdlTerminate =====================================================
 * Abstract:
 *    In this function, you should perform any actions that are necessary
 *    at the termination of a simulation.  For example, if memory was
 *    allocated in mdlStart, this is the place to free it.
 */
static void mdlTerminate(SimStruct *S)
{
}


/*=============================*
 * Required S-function trailer *
 *=============================*/

#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