title: c++ save matrix data into text or XML (better)
body: <p>I created a file.dat whith this function</p>
  
  <pre><code>int writeData(double* v, int length, FILE* fh)
  {
      FILE *Stream;     //Stream for output.
      double*Elem;     //Pointer to all the element to save.
  
      assert( fh!=NULL );
      Stream = fh;
  
      Elem=(double*)malloc((length+2)*sizeof(double));//Allocate memory to Elem.
      if(Elem==NULL)
      {
          printf("Can't allocate memory for saving the matrix!");
          return(0);
      }
  
      Elem[0]=(double)1;//Save the dimensions of the matrix.
      Elem[1]=(double)length;
  
      int i;
      for(i=0;i&lt;length ;i++) 
          Elem[i+2]=v[i];
  
      if(fwrite((void*)Elem,sizeof(double),(length+2),Stream) &lt; (unsigned)(length+2)) //Save the data.
      {
          printf("Error, can't save the matrix!");
          return(0);
      }
      free(Elem);
      return(1);
  }
  </code></pre>
  
  <p>Now I'd like to convert this file into an xml one or into a text file...</p>
  
  <p>Any tips?
  Thanks</p>