swritwks.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 19:07:00 $
 */
#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)) {
#ifdef MATLAB_MEX_FILE
	if (mxGetString(DATA_TYPE, dataType, sizeof(dataType)) != 0) {
	    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);
		    }
		}
#ifdef MATLAB_MEX_FILE
		if (strlen(eval_string) >= 10240) {
		    mexErrMsgTxt("Input vector length is too big to handle in trigged to workspace block.");
		}
		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);
		}
#ifdef MATLAB_MEX_FILE
		if (strlen(eval_string) >= 10240) {
		    mexErrMsgTxt("Input vector length is too big to handle in trigged to workspace block.");
		}
		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(double *dx, double *x, double *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");
#ifdef MATLAB_MEX_FILE
    /* make temperary space */
    sprintf(eval_string, "clear %s;", varname);
    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