reading ASCII data in s-function from a file

Question

Tushar 2011-4-7

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/4984-reading-ascii-data-in-s-function-from-a-file

Hello all,

I am interested in reading ASCII data in s-function from a file. I am trying to read the data [21;77;46;183;202;84;199;198;27;84] from the file datafile.dat. I am trying to display the data in Scope using *z = ssGetOutputPortSignal(S,0); . But when I run the corresponding Model I could see that only first 5 numbers are read i.e. 21;77;46;183;202. Following is the code:

#define S_FUNCTION_NAME  sfunread
#define S_FUNCTION_LEVEL 2
#include "simstruc.h"
#include <stdio.h>
static void mdlInitializeSizes(SimStruct *S)
{
    ssSetNumSFcnParams(S, 0); 
    if (ssGetNumSFcnParams(S) != ssGetSFcnParamsCount(S)) {
        return;
    }
    ssSetNumContStates(S, 0);
    ssSetNumDiscStates(S, 0);
    if (!ssSetNumInputPorts(S, 0)) return;
    if (!ssSetNumOutputPorts(S, 1)) return;
    ssSetOutputPortWidth(S, 0, 10);
    ssSetOutputPortDataType(S,0,SS_SINGLE);
    ssSetNumPWork(S,1);
    ssSetNumSampleTimes(S, 1);
}
static void mdlInitializeSampleTimes(SimStruct *S)
{
    ssSetSampleTime(S, 0, 1.0);
    ssSetOffsetTime(S, 0, 0.0);
}
#define MDL_START  
#if defined(MDL_START)   
  static void mdlStart(SimStruct *S)
  {
      void** pwork = ssGetPWork(S);
      FILE *datafile;
      datafile = fopen("datafile.dat","r");
      pwork[0] =  datafile;
}
#endif /*  MDL_START */
static void mdlOutputs(SimStruct *S, int_T tid)
{
  int l;
  real_T       *z = ssGetOutputPortSignal(S,0);
    void** pwork = ssGetPWork(S);
    for (l=0;l<10;l++){
         real_T temp;
         fscanf(pwork[0],"%f",&temp);
         z[l]=temp;
}
static void mdlTerminate(SimStruct *S)
{
     void** pwork = ssGetPWork(S);
      FILE *datafile;
      datafile = pwork[0];
      fclose(datafile);      
}
#ifdef  MATLAB_MEX_FILE    
#include "simulink.c"      
#else
#include "cg_sfun.h"       
#endif

Please let me know if I am using the correct way to read the ASCII data from a file.

Tushar

2 个评论
显示无隐藏无

Kaustubha Govind 2011-4-7

How is the data in your file delimited? Are there spaces between the numbers?

Tushar 2011-4-11

The delimiter is next line character '\n'. Each element of the array is on the next line.

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Jarrod Rivituso 2011-4-7

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/4984-reading-ascii-data-in-s-function-from-a-file#answer_6939

Your overall approach looks good. I would suggest debugging the S-function so you can step through it. There are steps on how to do that here:

http://www.mathworks.com/support/tech-notes/1800/1819.html

Also, did you copy and paste that code directly? There seems to be a missing } to end your for loop. I was looking for something subtle in your code and noticed that (I doubt that is the problem, but it makes me suspicious of whether this code actually contains the problem).

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

Answer 2

Tushar 2011-4-13

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/4984-reading-ascii-data-in-s-function-from-a-file#answer_7563

Hello

I tried to debug my s-function in Visual C. For simplicity I tried to read array with 5 elements [21;77;46;183;202] from a file. But the values of the elements in z array in the above code are displayed like

5.442276802756e-315#DEN

5.520634191278e-315#DEN

5.488902686835e-315#DEN

5.571469356558e-315#DEN

5.577621382930e-315#DEN

in stead of the true values [21;77;46;183;202]. Please some one comment on this.

5 个评论
显示 3更早的评论隐藏 3更早的评论

Tushar 2011-4-15

Thanks Jarrod. The code runs correctly with real32_T.

Its not clear why I had to change to real32_T from real_T. What is the difference between real_T, real32_T and real64_T? I did not find any reference for these data types in Matlab help files. real_T does not work even for integer type data in the file. Also "%lf" could not read the data from the file.

Jarrod Rivituso 2011-4-17