swriwks.c

数字通信第四版原书的例程

/*
 * SWRITFIL  A SIMULINK trigged write to a workspace variable.
 *
 *  Syntax:  [sys, x0] = swritwks(t,x,u,flag, varname, format, pulnum, threshold)
 *  This function has two inputs and no outputs. The first input is
 *  the signal to be stored. The second signal is the clock pulse.
 *
 *  varname is a string for the variable name.
 *  format   is the format to be written into the variable. The choices are:
 *            "data", "ascii"
 *  pulnum   number of pulses between saved data. If pulnum is a two 
 *           dimentional vector, the second element is the number of
 *           'offset' pulse before the first data is saved.
 *
 * Wes Wang  Feb. 7, 1995
 * Copyright (c) 1995-96 by The MathWorks, Inc.
 * All Rights Reserved
 * $Revision: 1.1 $  $Date: 1996/04/01 19:07:12 $
 */

#define S_FUNCTION_NAME swritwks

#include <stdio.h>    /* needed for declaration of sprintf */
#include <string.h>    /* needed for string operation */

#ifdef MATLAB_MEX_FILE
#include "mex.h"      /* needed for declaration of mexErrMsgTxt */
#endif

/*
 * need to include simstruc.h for the definition of the SimStruct and
 * its associated macro definitions.
 */

#include "simstruc.h"

/*
 * Defines for easy access of the input parameters
 */

#define NUM_ARGS      6
/* file name for the data to be saved */
#define VARNAME       ssGetArg(S, 0)
/* data type, which is a string of ASCII, Integer, float, or binary */
#define DATA_TYPE     ssGetArg(S, 1)
/* number of pulse count to trigger one saving record */
#define NUM_IN_BT     ssGetArg(S, 2)
/* maximum size of the data storage */
#define MAX_SIZE      ssGetArg(S, 3)
/* keep which part of the data 0--begin 1--end */
#define CUT_FLAG      ssGetArg(S, 4)
/* threshold in detecting the raising edge. */
#define THRESHOLD     ssGetArg(S, 5)

/*
 * mdlInitializeSizes - called to initialize the sizes array stored in
 *                      the SimStruct.  The sizes array defines the
 *                      characteristics (number of inputs, outputs,
 *                      states, etc.) of the S-Function.
 */

static void mdlInitializeSizes(S)
     SimStruct *S;
{
    /*
     * Set-up size information.
     */ 
    
    if (ssGetNumArgs(S) == NUM_ARGS) {
	int i;
	if ((mxGetN(VARNAME) > 1) && (mxGetM(VARNAME) > 1)) {
#ifdef MATLAB_MEX_FILE
	    char err_msg[256];
	    sprintf(err_msg, "Variable name should be a string vector.");
	    mexErrMsgTxt(err_msg);
#endif  
        }

	if ((mxGetN(DATA_TYPE) > 1) && (mxGetM(DATA_TYPE) > 1)) {
#ifdef MATLAB_MEX_FILE
	    char err_msg[256];
	    sprintf(err_msg, "Data Type should be a string vector.");
	    mexErrMsgTxt(err_msg);
#endif  
        }

	if (mxGetN(MAX_SIZE) * mxGetM(MAX_SIZE) > 1) {
#ifdef MATLAB_MEX_FILE
	    char err_msg[256];
	    sprintf(err_msg, "Data maximum storage size must be scalar.");
	    mexErrMsgTxt(err_msg);
#endif  
        }

	if (mxGetN(CUT_FLAG) * mxGetM(CUT_FLAG) > 1) {
#ifdef MATLAB_MEX_FILE
	    char err_msg[256];
	    sprintf(err_msg, "Storage keeping flag must be a scalar.");
	    mexErrMsgTxt(err_msg);
#endif  
        }

	if ((mxGetN(NUM_IN_BT) * mxGetM(NUM_IN_BT) > 2) || (mxGetN(NUM_IN_BT) * mxGetM(NUM_IN_BT) < 1) ) {
#ifdef MATLAB_MEX_FILE
	    char err_msg[256];
	    sprintf(err_msg, "Dimension for trigger pulse number is incorrect.");
	    mexErrMsgTxt(err_msg);
#endif  
        }
       
	ssSetNumContStates(    S, 0);
	ssSetNumDiscStates(    S, 0);
	ssSetNumInputs(        S, -1);
	ssSetNumOutputs(       S, 1);
	ssSetDirectFeedThrough(S, 0);
	ssSetNumInputArgs(     S, NUM_ARGS);
	ssSetNumSampleTimes(   S, 1);
	ssSetNumRWork(         S, 0);
	ssSetNumIWork(         S, 4);
	/* 1st: 0--start, not passed offset; 1--regular calculation
	 * 2nd: accumulate accounting for the how many pulse passed
	 * 3rd: 0: last trigger signal was below threshold 1: last trigger signal was above threshold
	 * 4th: index of the saving point
	 */
	ssSetNumPWork(         S, 0);
    } else {
#ifdef MATLAB_MEX_FILE
	char err_msg[256];
	sprintf(err_msg, "Wrong number of input arguments passed to S-function MEX-file.\n"
		"%d input arguments were passed in when expecting %d input arguments.\n", ssGetNumArgs(S) + 4, NUM_ARGS + 4);
	mexErrMsgTxt(err_msg);
#endif
    }
}

/*
 * mdlInitializeSampleTimes - initializes the array of sample times stored in
 *                            the SimStruct associated with this S-Function.
 */

static void mdlInitializeSampleTimes(S)
     SimStruct *S;
{
  /*
   * Note, blocks that are continuous in nature should have a single
   * sample time of 0.0.
   */
  
  ssSetSampleTimeEvent(S, 0, 0.0);
  ssSetOffsetTimeEvent(S, 0, 0.0);
}

/*
 * mdlInitializeConditions - initializes the states for the S-Function
 */

static void mdlInitializeConditions(x0, S)
     double *x0;
     SimStruct *S;
{
  int    *CountFlag      = ssGetIWork(S);
  int    *CountNum       = ssGetIWork(S) + 1;
  int    *LastTrig       = ssGetIWork(S) + 2;
  int    *RowIndex       = ssGetIWork(S) + 3;

  *CountFlag = 0;
  *CountNum  = 0;
  *LastTrig  = 0;
}

/*
 * mdlOutputs - computes the outputs of the S-Function
 */

static void mdlOutputs(y, x, u, S, tid)
     double *y, *x, *u;
     SimStruct *S;
     int tid;
{
  int    *CountFlag      = ssGetIWork(S);
  int    *CountNum       = ssGetIWork(S) + 1;
  int    *LastTrig       = ssGetIWork(S) + 2;
  int    *RowIndex       = ssGetIWork(S) + 3;
  
  double  trigThreshold   = mxGetPr(THRESHOLD)[0];
  
  int     numInput       = ssGetNumInputs(S);
  int     i;
  
  char   varname[32];
  char   dataType[10];
  
  if ((*RowIndex > mxGetPr(MAX_SIZE)[0]) && (mxGetPr(CUT_FLAG)[0] <= 0)) {
    /* need not process */
    y[0] = 0;
    return;
  }
  
  /*
   * acquire the buffer data
   */
  if ((u[numInput-1] >= trigThreshold) & (*LastTrig == 0)){
   
/*    if (mxGetString(DATA_TYPE, dataType, sizeof(dataType)) != 0)
#ifdef MATLAB_MEX _FILE
      mexErrMsgTxt("Error in Data Type specification.");
#endif
*/
    *CountNum += 1;
    if (*CountFlag) {
      /* action when count number is larger or equal to number count */
      int NumberInBetween = (int)mxGetPr(NUM_IN_BT)[0];
      
      if (*CountNum > NumberInBetween) {
	char eval_string[10240];
	char temp_string[10240];
	
	/* reset Count */
	*CountNum = 0;
	*RowIndex += 1;
	
	sprintf(temp_string, "[");
	for (i = 0; i < numInput-1; i++) {
	  sprintf(eval_string, "  %f", u[i]);
	  strcat(temp_string, eval_string);
	}
	sprintf(eval_string, "]");
	strcat(temp_string, eval_string);
	
	mxGetString(VARNAME, varname, sizeof(varname));
	
	/* assign the u value in varnae_temp to varname */
	if (*RowIndex <= mxGetPr(MAX_SIZE)[0]) {
	  if ((strcmp(dataType, "ascii") == 0) || (strcmp(dataType, "ASCII") == 0)) {
	    sprintf(eval_string, "%s = [%s, setstr( %s )];", varname, varname, temp_string);
	  } else {
	    sprintf(eval_string, "%s = [%s; %s];", varname, varname, temp_string);
	  }
	} else {
	  int max_m_1 = (int)mxGetPr(MAX_SIZE)[0];
	  
	  max_m_1 -= 1;
	  
	  if ((strcmp(dataType, "ascii") == 0) || (strcmp(dataType, "ASCII") == 0)) {
	    sprintf(eval_string, "%s = [%s(1 : %i), setstr( %s )];", varname, varname, (max_m_1) * (numInput-1), temp_string);
	  } else {
	    sprintf(eval_string, "%s = [%s(1 : %i, :); %s];", varname, varname, max_m_1, temp_string);
	  }
	}
	if (strlen(eval_string) >= 10240) {
#ifdef MATLAB_MEX_FILE
	  mexErrMsgTxt("Input vector length is too big to handle in trigged to workspace block.");
#endif
	}
#ifdef MATLAB_MEX_FILE
	mexEvalString(eval_string);
#endif
      }
    } else {
      i = 0;
      if ((mxGetN(NUM_IN_BT) * mxGetM(NUM_IN_BT)) < 2) {
	i = 1;
      } else {
	if (*CountNum > mxGetPr(NUM_IN_BT)[1])
	  i = 1;
      }
      if (i) {
	/* this part will be run once only. */
	char eval_string[10240];
	char temp_string[10240];
	sprintf(temp_string, "[");
	for (i = 0; i < numInput - 1; i++) {
	  sprintf(eval_string, "  %f", u[i]);
	  strcat(temp_string, eval_string);
	}
	sprintf(eval_string, "]");
	strcat(temp_string, eval_string);
	
	mxGetString(VARNAME, varname, sizeof(varname));
	
	/* assign the u value in varname_temp to varname */
	if ((strcmp(dataType, "ascii") == 0) || (strcmp(dataType, "ASCII") == 0)) {
	  sprintf(eval_string, "%s = setstr( %s );", varname, temp_string);
	} else {
	  sprintf(eval_string, "%s = %s;", varname, temp_string);
	}
	if (strlen(eval_string) >= 10240) {
#ifdef MATLAB_MEX_FILE
	  mexErrMsgTxt("Input vector length is too big to handle in trigged to workspace block.");
#endif
	}
#ifdef MATLAB_MEX_FILE
	mexEvalString(eval_string);
#endif
	/* set flag, the Count flag setting avoid duplication of open file */
	*CountFlag = 1;
	*CountNum  = 0;
	*RowIndex  = 1;
      }
    }
  }
  if (u[numInput-1] >= trigThreshold) {
    *LastTrig = 1;
  } else {
    *LastTrig = 0;
  }
  y[0] = 0;
}

/*
 * mdlUpdate - computes the discrete states of the S-Function
 */

static void mdlUpdate(x, u, S, tid)
     double *x, *u;
     SimStruct *S;
     int tid;
{
}

/*
 * mdlDerivatives - computes the derivatives of the S-Function
 */

static void mdlDerivatives(dx, x, u, S, tid)
     double *dx, *x, *u; 
     SimStruct *S;
     int tid;
{
}

/*
 * mdlTerminate - called at termination of model execution.
 */

static void mdlTerminate(S)
     SimStruct *S;
{
  char varname[40], eval_string[256];
  mxGetString(VARNAME, varname, sizeof(varname));
  strcat(varname, "_temp_sww");
  
  /* make temperary space */
  sprintf(eval_string, "clear %s;", varname);
#ifdef  MATLAB_MEX_FILE
  mexEvalString(eval_string);
#endif
}

#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