How can I declare an "uint8 RowVector"?

[Roberto Vidmar]

Hi to all,

I need to read and process a binary file made of 553 byte records. 
Every record contains many data and, among these, 3 arrays of uint8 values.
First I wrote an octave function to store every record in an octave 
structure using fread and uint8 convertion funcion:

...
RpfRecord.ret2 = uint8(fread(rpfid, 220, 'uint8'));
...

...but this is far to slow for my purpouses so I tried to move the 
reading part into a dynamic loadable function written in C++ (but I'm 
NOT a C++ programmer, I know only non-object oriented languages).

My C++ function opens the file, reads it, and returns a structure, at 
preset just a single record not yet a vector. The code follows:

#include <octave/oct.h>
#include <octave/ov-struct.h>
#include <rpf-a.h>

DEFUN_DLD (readrpf, args, ,
"Read RPF file into RPF structure.\n\
\n\
Reference:\n\
\n\
Roberto Vidmar Jannuary 2006.\n\
Last Update: 20060111.")

{
octave_value_list  retval;
rpf_record_t       rpf_record;
RowVector          t0(40);  # I know this declares an array of double, 
but I'm not able to declare an uint8 array.....
FILE *             rpf_fp;
int                bytesread=0;

rpf_fp=fopen("outfile.rpf.recs", "r");
bytesread=fread(&rpf_record.gpstime,       1, 
sizeof(rpf_record.gpstime),      rpf_fp);
bytesread+=fread(&rpf_record.pulsecount,   1, 
sizeof(rpf_record.pulsecount),   rpf_fp);
bytesread+=fread(&rpf_record.range,        1, 
sizeof(rpf_record.range),        rpf_fp);
bytesread+=fread(&rpf_record.intensity,    1, 
sizeof(rpf_record.intensity),    rpf_fp);
bytesread+=fread(&rpf_record.scanangle,    1, 
sizeof(rpf_record.scanangle),    rpf_fp);
bytesread+=fread(&rpf_record.roll,         1, 
sizeof(rpf_record.roll),         rpf_fp);
bytesread+=fread(&rpf_record.pitch,        1, 
sizeof(rpf_record.pitch),        rpf_fp);
bytesread+=fread(&rpf_record.heading,      1, 
sizeof(rpf_record.heading),      rpf_fp);
bytesread+=fread(&rpf_record.aircraft_lat, 1, 
sizeof(rpf_record.aircraft_lat), rpf_fp);
bytesread+=fread(&rpf_record.aircraft_lon, 1, 
sizeof(rpf_record.aircraft_lon), rpf_fp);
bytesread+=fread(&rpf_record.aircraft_ele, 1, 
sizeof(rpf_record.aircraft_ele), rpf_fp);
bytesread+=fread(&rpf_record.t1,           1, 
sizeof(rpf_record.t1),           rpf_fp);
bytesread+=fread(&rpf_record.t2,           1, 
sizeof(rpf_record.t2),           rpf_fp);
bytesread+=fread(&rpf_record.t0,           1, 
sizeof(rpf_record.t0),           rpf_fp);
bytesread+=fread(&rpf_record.ret1,         1, 
sizeof(rpf_record.ret1),         rpf_fp);
bytesread+=fread(&rpf_record.ret2,         1, 
sizeof(rpf_record.ret2),         rpf_fp);
printf("----- bytesread=%d -----\n\n", bytesread);

Octave_map stru( "Field1" , "Filed1_value");  stru.assign("gpstime", 
rpf_record.gpstime);

stru.assign("pulsecount", rpf_record.pulsecount);
stru.assign("range", &rpf_record.range);
stru.assign("intensity", rpf_record.intensity);
stru.assign("scanangle", rpf_record.scanangle);
stru.assign("roll", rpf_record.roll);
stru.assign("pitch", rpf_record.pitch);
stru.assign("heading", rpf_record.heading);
stru.assign("aircraft_lat", rpf_record.aircraft_lat);
stru.assign("aircraft_lon", rpf_record.aircraft_lon);
stru.assign("aircraft_ele", rpf_record.aircraft_ele);
stru.assign("t1", rpf_record.t1);
stru.assign("t2", rpf_record.t2);
{
  int i;
  for (i=0; i<40; i++)
      t0(i)=rpf_record.t0[i];
}
stru.assign("t0", t0);
retval.append(stru);
return retval;
}

This works and returns the first record of the file in a structure. The 
problem is that t0 is a....

whos return_value.t0

*** local user variables:

Prot Name        Size                     Bytes  Class
==== ====        ====                     =====  =====
 rwd return_value.t0        1x40                       320  matrix

Total is 40 elements using 320 bytes

How can I declare t0 in a way that my function will return a 40 byte 
uint8 vector?
And is it possible to return directly an array of structures?

Any help will be appreciated

Roberto Vidmar

--
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Roberto Vidmar 
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