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Required Reading


   CSPICE_DSKB02 return bookkeeping data from a DSK type 2 segment.



      handle    the handle of a DSK file containing a type 2
                segment from which data are to be fetched.

                [1,1] = size(handle); int32 = class(handle)

      dladsc    the DLA descriptor associated with the segment
                from which data are to be fetched.

                [SPICE_DLA_DSCSIZ,1]  = size(dladsc)
                                int32 = class(dladsc)

   the call:


      nv         the number of vertices belonging to the specified plate

                 [1,1] = size(nv); int32 = class(nv)

      np         the number of plates belonging to the specified plate

                 [1,1] = size(np); int32 = class(np)

      nvxtot     Total number of voxels in fine grid.

                 [1,1] = size(nvxtot); int32 = class(nvxtot)

      vtxbds     Vertex bounds. This is an array of six values giving
                 the minimum and maximum values of each component of
                 the vertex set. Units are km.

                 [2,3] = size(vtxbds); double = class(vtxbds)

      voxsiz     Fine grid voxel size.  DSK voxels are cubes; the edge
                 length of each cube is given by the voxel size.  This
                 size applies to the fine voxel grid.  Units are km.

                 [1,1] = size(voxsiz); double = class(voxsiz)

      voxori     Voxel grid origin.  This is the location of the voxel
                 grid origin in the body-fixed frame associated with
                 the target body.  Units are km.

                 [3,1] = size(voxori); double = class(voxori)

      vgrext     Voxel grid extent.  This extent is an array of three
                 integers indicating the number of voxels in the X, Y, and
                 Z directions in the fine voxel grid.

                 [3,1] = size(vgrext); int32 = class(vgrext)

      cgscal     Coarse voxel grid scale.  The extent of the fine voxel
                 grid is related to the extent of the coarse voxel grid by
                 this scale factor.

                 [1,1] = size(cgscal); int32 = class(cgscal)

      vtxnpl     Vertex-plate correspondence list size.

                 [1,1] = size(vtxnpl); int32 = class(vtxnpl)

      voxnpt     Size of the voxel-to-plate pointer list.

                 [1,1] = size(voxnpt); int32 = class(voxnpt)

      voxnpl     Voxel-plate correspondence list size.

                 [1,1] = size(voxnpl); int32 = class(voxnpl)


   Any numerical results shown for this example may differ between
   platforms as the results depend on the SPICE kernels used as input
   and the machine specific arithmetic implementation.


      Dump several parameters from the first DLA segment of
      a DSK file. The segment is assumed to be of type 2.

      function dskb02_t( dsk )

         % Open the DSK file for read access. We use the
         % DAS-level interface for this function.
         handle = cspice_dasopr( dsk );

         % Begin a forward search through the kernel. In
         % this example, it's a very short search.
         [ dladsc, found] = cspice_dlabfs( handle );

         if ~found

            txt = sprintf( ...
               'SPICE(NOSEGMENT): No segment found in file %s.', ...



         % Loop over each segment.
         while found

            % If we made it this far, DLADSC is the
            % DLA descriptor of the first segment.
            % Read and display type 2 bookkeeping data.
            [ nv, np, nvxtot, vtxbds, voxsiz, voxori, vgrext, ...
            cgscal, vtxnpl, voxnpt, voxnpl] = cspice_dskb02( handle, dladsc);

            fprintf( ['\n'                                              ...
                     'Number of vertices:                 %ld\n'        ...
                     'Number of plates:                   %ld\n'        ...
                     'Number of voxels:                   %ld\n'        ...
                     'Vertex bounds in X direction (km):  %f : %f\n'    ...
                     'Vertex bounds in Y direction (km):  %f : %f\n'    ...
                     'Vertex bounds in Z direction (km):  %f : %f\n'    ...
                     'Voxel edge length (km):             %f\n'         ...
                     'Voxel grid origin (km):           ( %f %f %f )\n' ...
                     'Voxel grid extents:                 %ld %ld %ld\n'...
                     'Coarse voxel grid scale:            %ld\n'        ...
                     'Size of vertex-plate list:          %ld\n'        ...
                     'Size of voxel-plate pointer array:  %ld\n'        ...
                     'Size of voxel-plate list:           %ld\n'],      ...
                     nv,                              ...
                     np,                              ...
                     nvxtot,                          ...
                     vtxbds(1,1), vtxbds(2,1),        ...
                     vtxbds(1,2), vtxbds(2,2),        ...
                     vtxbds(1,3), vtxbds(2,3),        ...
                     voxsiz,                          ...
                     voxori(1), voxori(2), voxori(3), ...
                     vgrext(1), vgrext(2), vgrext(3), ...
                     cgscal,                          ...
                     vtxnpl,                          ...
                     voxnpt,                          ...
                     voxnpl )

               % Search for the segment after that described by 'dladsc'.
               % 'found' returns as false if no such segment located.
               [nxtdsc, found] = cspice_dlafns( handle, dladsc);

               dladsc = nxtdsc;


         % Close the kernel. This frees program and system resources.
         cspice_dascls( handle );

   MATLAB outputs:

      >> dskb02_t( 'phobos512.bds' )

      Number of vertices:                 1579014
      Number of plates:                   3145728
      Number of voxels:                   11914500
      Vertex bounds in X direction (km):  -13.440030 : 12.762800
      Vertex bounds in Y direction (km):  -11.520650 : 12.061140
      Vertex bounds in Z direction (km):  -9.570780 : 10.055000
      Voxel edge length (km):             0.104248
      Voxel grid origin (km):           ( -14.073520 -11.988554 -9.903588 )
      Voxel grid extents:                 260 235 195
      Coarse voxel grid scale:            5
      Size of vertex-plate list:          11010050
      Size of voxel-plate pointer array:  1151500
      Size of voxel-plate list:           6419540


   This routine supports computations involving bookkeeping information
   stored in DSK type 2 segments. User applications typically will not
   need to call this routine.

   DSK files are built using the DLA low-level format and the DAS
   architecture; DLA files are a specialized type of DAS file in which
   data are organized as a doubly linked list of segments.  Each
   segment's data belong to contiguous components of character, double
   precision, and integer type.

Required Reading

   For important details concerning this module's function, please
   refer to the CSPICE routine dskb02_c.



   -Mice Version 1.0.0, 27-APR-2016, EDW (JPL), NJB (JPL)


   fetch parameters from a type 2 dsk segment

Wed Apr  5 18:00:30 2017