Read binary data

Library

Sources

Description

This block allows user to read datas in a C file. Output record selection and Time record Selection allows the user to select data among file records. Each call to the block advance one record in the file.

Dialog Box

Set READC block parameters
Time record selection	[]
Outputs record selection	1
Input file name	foo
Input Format	d
Record size	1
Buffer size (in records)	20
Initial record index	1
Swap mode 0/1	0

• Time record selection: an empty matrix or a positive integer. If an integer i is given the i th element of the read record is assumed to be the date of the output event. If empty no output event exists.
• Outputs record selection: a vector of positive integer. $[k_1,\cdots,k_n]$ ,The $k_i$ th element of the read record gives the value of $i$th output.
• Input file name:a character string defining the path of the file.
• Input Format: a character string defining the format to use.
• Record size: The file is supposed to be formed by a sequence of data with same format. these data are organized in a sequence of record each of them containing Record size data.
• Buffer size : To improve efficiency it is possible to buffer the input data. read on the file is only done after each Buffer size call to the block.
• Initial record index: a scalar. This fixes the first record of the file to use.
• Swap mode 0/1: With Swap mode=1 the file is supposed to be coded in "little endian IEEE format" and data are swaped if necessary to match the IEEE format of the processor. If Swap mode=0 then automatic bytes swap is disabled.

Default properties

• always active: no
• direct-feedthrough: no
• zero-crossing: no
• mode: no
• number/sizes of inputs: 0 /
• number/sizes of outputs: 1 / 1
• number/sizes of activation inputs: 1 / 1
• number/sizes of activation outputs: 0 /
• continuous-time state: no
• discrete-time state: yes
• name of computational function: readc

Interfacing function

scilab/macros/scicos_blocks/sources/READC_f.sci

Computational function (type 2)

#include <stdio.h>
#include <string.h>

#include "../machine.h"
extern  int C2F(cvstr)  __PARAMS((integer *,integer *,char *,integer *,unsigned long int));
extern void sciprint __PARAMS((char *fmt,...));
extern void mget2 __PARAMS((FILE *fa, integer swap, double *res, integer n, char *type, integer *ierr));


int worldsize(type)
char type[4];
{
  char c;
  int wsz;

  c=type[0];
  if (c=='u') c=type[1];
  switch ( c )
    {
    case 'l' : wsz=sizeof(long);
      break;
    case 's' : wsz=sizeof(short);
      break;
    case 'c' : wsz=sizeof(char);
      break;
    case 'd' : wsz=sizeof(double);
      break;
    case 'f' : wsz=sizeof(float); 
      break;
    }
  return wsz;
}
void 
readc(flag,nevprt,t,xd,x,nx,z,nz,tvec,ntvec,rpar,nrpar,
	       ipar,nipar,inptr,insz,nin,outptr,outsz,nout)
     /*
     ipar[1]   = lfil : file name length
     ipar[2:4] = fmt  : numbers type ascii code
     ipar[5]   = is there a time record
     ipar[6]   = n : buffer length in number of records
     ipar[7]   = maxvoie : record size
     ipar[8]   = swap
     ipar[9]   = first : first record to read
     ipar[10:9+lfil] = character codes for file name
     ipar[10+lfil:9+lfil++ny+ievt] = reading mask
     */
integer *flag,*nevprt,*nx,*nz,*ntvec,*nrpar,ipar[],*nipar;
integer insz[],*nin,outsz[],*nout;
double x[],xd[],z[],tvec[],rpar[];
double *inptr[],*outptr[],*t;

{
  char str[100],type[4];
  int job = 1,three=3;
  FILE *fd;
  int n, k, ievt, kmax,/* no,*//* lfil,*/ m, i, irep,/* nm,*/ ierr;
  double *buffer,*record;
  int *mask;
  long offset;
  

  --ipar;
  --z;
  fd=(FILE *)(long)z[3];
  buffer = (z+4);
  mask = ipar+11+ipar[1]-ipar[5];
    
  /*
    k    : record counter within the buffer
    kmax :  number of records in the buffer
  */

  if (*flag==1) {
    n    = ipar[6];
    ievt = ipar[5];
    k    = (int)z[1];
    /* copy current record to output */
    record=buffer+(k-1)*ipar[7]-1;

    for (i=0;i<outsz[0];i++)
      *(outptr[0]+i)=record[mask[ievt+i]];

    if (*nevprt>0) {
      /*     discrete state */
      kmax = (int)z[2];
      if (k>=kmax&&kmax==n) {
	/*     read a new buffer */
	m=ipar[6]*ipar[7];
	F2C(cvstr)(&three,&(ipar[2]),type,&job, strlen(type));
	for (i=2;i>=0;i--)
	  if (type[i]!=' ') { type[i+1]='\0';break;}
	ierr=0;
	mget2(fd,ipar[8],buffer,m,type,&ierr);
	if (ierr>0) {
	  sciprint("Read error!\n");
	  fclose(fd);
	  z[3] = 0.0;
	  *flag = -1;
	  return;
	}
	else if (ierr<0) { /* EOF reached */
	  kmax=-(ierr+1)/ipar[7];
	}
	else
	  kmax=ipar[6];

	z[1] = 1.0;
	z[2] = kmax;
      }
      else if (k<kmax) 
	z[1] = z[1]+1.0;
    }
  }
  else if (*flag==3) {
    ievt = ipar[5];
    n    = ipar[6];
    k    = (int)z[1];
    kmax = (int) z[2];
    if (k > kmax && kmax < n) {
      if(ievt) 
	tvec[0] = *t-1.0;
      else
	tvec[0] = *t*(1.0+0.0000000001);
    }
    else {
      record=buffer+(k-1)*ipar[7]-1;
      if(ievt) tvec[0] = record[mask[0]];
    }
  }
  else if (*flag==4) {
    F2C(cvstr)(&(ipar[1]),&(ipar[10]),str,&job,strlen(str));
    str[ipar[1]] = '\0';
    fd = fopen(str,"rb");
    if (!fd ) {
      sciprint("Could not open the file!\n");
      *flag = -1;
      return;
    }
    z[3]=(long)fd;
    /* skip first records */
    if (ipar[9]>1) {
      F2C(cvstr)(&three,&(ipar[2]),type,&job,strlen(type));
      for (i=2;i>=0;i--)
	  if (type[i]!=' ') { type[i+1]='\0';break;}
      offset=(ipar[9]-1)*ipar[7]*worldsize(type);
      irep = fseek(fd,offset,0) ;
      if ( irep != 0 ) 
	{
	  sciprint("Read error\r\n");
	  *flag = -1;
	  fclose(fd);
	  z[3] = 0.0;
	  return;
	}
    }
    /* read first buffer */
    m=ipar[6]*ipar[7];
    F2C(cvstr)(&three,&(ipar[2]),type,&job,strlen(type));
    for (i=2;i>=0;i--)
	  if (type[i]!=' ') { type[i+1]='\0';break;}
    mget2(fd,ipar[8],buffer,m,type,&ierr);
    if (ierr>0) {
      sciprint("Read error!\n");
      *flag = -1;
      fclose(fd);
      z[3] = 0.0;
      return;
    }
    else if (ierr<0) { /* EOF reached */
      kmax=-(ierr+1)/ipar[7];
    }
    else
      kmax=ipar[6];

    z[1] = 1.0;
    z[2] = kmax;
  }
  else if (*flag==5) {
    if(z[3]==0) return;
    fclose(fd);
    z[3] = 0.0;
  }
  return;
}