[Paraview] binary file error

[Massimiliano Di Domenico]

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Hello everybody
  I am starting to use Paraview why I would like to get a valid (and free :-) 
substitute of programs like Tecplot. 
I have two questions:
1- Is it possible to select different scalar variables from a VTK file? I have 
searched in the documentation but I did not find anything...

2- I am approaching the common problem to write a "translator" from my file 
format to VTK file format. If I write a ASCII file I have no problem to read 
it with Paraview, but when try to write a binary file I can not read it (I 
get a segmentation fault error). I am not a C expert but the code that I 
wrote (see attached file test.c) produce a valid output (see out.vtk), at 
least for points coordinates.
 Can you help me?

Thank you

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

#define VTKVERSION "3.0"

static FILE *vtkfile;

static int binary;

/*------------------------------------------------------------------------------
| Initialize VTK file
------------------------------------------------------------------------------*/
void vtkinit(char *vtkfilename, char *title, int bin_flg)
{
  if( bin_flg )
  {
    vtkfile = fopen(vtkfilename, "wb");
    binary = TRUE;
  }
  else
  {
    vtkfile = fopen(vtkfilename, "w");
    binary = FALSE;
  }
  
  if(vtkfile == NULL)
    fatal_error("Can not open file %s!!\n", vtkfilename);
    
  fprintf(vtkfile, "# vtk DataFile Version %s\n", VTKVERSION);
    
  fprintf(vtkfile, "%s\n", title);
  
  if(bin_flg)
    fprintf(vtkfile, "BINARY\n");
  else
    fprintf(vtkfile, "ASCII\n");
    
  fprintf(vtkfile, "DATASET UNSTRUCTURED_GRID\n");

}


/*------------------------------------------------------------------------------
| Write coordinates of gridpoints
------------------------------------------------------------------------------*/
void writegridpoint(double (*x)[3], PointMapping *pm)
{
  int pnt, i;
  long int ngridpnts = pm->np_grid;
  double dmydbl;
  int dmyint;
  
  fprintf(vtkfile, "POINTS %d double\n", ngridpnts);
  
  if( binary )
    for(pnt = 0; pnt < ngridpnts; pnt++)
      for(i = 0; i < 3; i++)
  	fwrite(&x[pnt][i], sizeof( double ), 1, vtkfile);
  }
  else
  {  
    for(pnt = 0; pnt < ngridpnts; pnt++)
    {
       for(i = 0; i < 3; i++)
  	  fprintf(vtkfile, " %g ", x[pnt][i]);
  	fprintf(vtkfile, "\n");
    }
  }

}


/*------------------------------------------------------------------------------
| Close VTK file
------------------------------------------------------------------------------*/
void vtkend(char *vtkfilename)
{
  fclose(vtkfile);
  printf("File %s closed\n", vtkfilename);
  printf("\n");
  fflush(stdout);
}


/*------------------------------------------------------------------------------
| test output file
------------------------------------------------------------------------------*/
void testgridpoint(char *vtkfilename, PointMapping *pm, int bin_flg)
{
  int pnt, i;
  int ngridpnts = pm->np_grid;
  char dummystr[1024];
  double x;
  
  if( bin_flg )
  {
    vtkfile = fopen(vtkfilename, "rb");
    binary = TRUE;
  }
  else
  {
    vtkfile = fopen(vtkfilename, "r");
    binary = FALSE;
  }
  
  
  for(i = 0; i < 4; i++)
  {
    fgets(dummystr, 1024, vtkfile);
    printf("%s\n", dummystr);
  }
  
  fscanf(vtkfile, "%s %d %s\n", dummystr, &ngridpnts, dummystr);

  printf("%s\n", dummystr);
  
  printf("Number of points:\t%d\n", ngridpnts);
  
  for(pnt = 0; pnt < ngridpnts; pnt++)
    for(i = 1; i < 3; i++)
    {
      fread(&x, sizeof( double ), 1, vtkfile);
      printf("val = %f\n", x);
    }
  
  
  fclose(vtkfile);
  
  
}



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Content-Disposition: attachment; filename="out.vtk"

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QVRBU0VUIFVOU1RSVUNUVVJFRF9HUklEClBPSU5UUyAxMCBkb3VibGUKAAAAAAAAAAC9CgDAd7yx
P9lQ/V/heqQ/AAAAAAAAAADZUP1f4Xq0PwAAAAAAAAAAAAAAAAAAAADXTPt/v2BMP3kk+d9NYkA/
AAAAAAAAAAC3/tzfTWJQPwAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAABg
He3fZ9glPwAAAAAAAAAAAAAAAAAAAAAiQwngZ9g1PwAAAAAAAAAAAAAAAAAAAAB5JPnfTWJAPwAA
AAAAAAAAAAAAAAAAAABBMPvfZ9hFPwAAAAAAAAAAAAAAAAAAAAAMUP6/gU5LPwAAAAAAAAAACgo=

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