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Abstract
I/O
Examples
Particulars
Required Reading
Version
Index_Entries

Abstract


   CSPICE_DSKP02 returns a specified set of triangular plates from a
   type 2 DSK segment.

I/O


   Given:

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

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

      start     is the ID of the first plate to be fetched from the
                segment designated by `handle' and `dladsc'. The ID
                of a plate is its ordinal position within the
                segment. Plate IDs range from 1 to NP, where NP is
                the number of plates in the segment.

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

                Note that Fortran-style 1-based indexing is used for
                plate IDs because these IDs must be consistent with
                the IDs used in DSK files, across all languages
                supported by SPICE.

      room      is the maximum number of plates to return.

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

   the call:

      [plates] = cspice_dskp02( handle, dladsc, start, room )

   returns:

      plates    is an array representing a contiguous set of `n' plates,
                where `n' is between 1 and `room' inclusive. The returned
                plates are arranged in order of increasing plate
                ID. The IDs of the returned plates range from

                   start

                to

                   start + n - 1

                Each "plate" consists of three vertex indices.
                The range of vertex indices is from 1 to NV, where NV is
                the number of vertices in the segment.

                [3,n] = size(plates); int32 = class(plates)

                The correspondence of elements of `plates' with the
                elements of the set of plates contained in the segment
                is:

                   plates(1,1)      plate_set(1, start)
                   plates(2,1)      plate_set(2, start)
                   plates(3,1)      plate_set(3, start)
                     ...             ...
                   plates(1,n)      plate_set(1, start+n-1)
                   plates(2,n)      plate_set(2, start+n-1)
                   plates(3,n)      plate_set(3, start+n-1)

                If an error occurs on the call, `plates' is
                undefined.

Examples


   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.

   Look up all the vertices associated with each plate
   of the model contained in a specified type 2 segment. For each
   plate, display the plate's vertices and normal vector.

   For this example, we'll show the context of this look-up:
   opening the DSK file for read access, traversing a trivial,
   one-segment list to obtain the segment of interest.

      function dskz02_t( dsk )

         %
         % Declare DSK Mice parameters for use in API calls.
         %
         DSKMiceUser

         %
         % Constants
         %
         PBUFSIZ = 10000;

         %
         % Initial values
         %
         verts = zeros(3,3);

         %
         % 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, treating the file as a DLA.
         % In this example, it's a very short
         % search.
         %
         [dladsc, found] = cspice_dlabfs( handle );

         if ~found

            %
            % We arrive here only if the kernel
            % contains no segments. This is
            % unexpected, but we're prepared for it.
            %
            fprintf( 'No segments found in DSK file %s\n', dsk )
            return

         end

         %
         % If we made it this far, `dladsc' is the
         % DLA descriptor of the first segment.
         %
         % Get segment vertex and plate counts.
         %
         [nv, np] = cspice_dskz02( handle, dladsc );

         fprintf( '\n' )
         fprintf( 'Number of vertices:  %d\n', nv )
         fprintf( 'Number of plates:    %d\n', np )

         %
         %  Display the vertices of each plate.
         %
         remain = np;
         start  = 1;

         while (remain > 0 )

            %
            % `nread' is the number of plates we"ll read on this
            % loop pass. Set `nread' to the minimum of PBUFSIZ
            % and `remain'.
            %
            nread = min(PBUFSIZ, remain);

            plates = cspice_dskp02( handle, dladsc, start, nread );

            for  i = 1:(nread)

               plix = start + i - 1;

               %
               %  Read the vertices of the current plate.
               %
               for  j = 1:3

                  verts(j,:) = cspice_dskv02( handle, ...
                                              dladsc, plates(j,i), 1 );

               end


               %
               % Display the vertices of the ith plate:
               %
               fprintf( '\n' )
               fprintf( 'Plate number: %d\n', i )

               for  j = 1:3
                  fprintf( '   Vertex %d: ( %16.8e %16.8e %16.8e )\n', ...
                                                         j, verts(j,:) )
               end

               %
               % Display the normal vector of the current plate:
               %
               normal = cspice_dskn02( handle, dladsc, plix );
               fprintf( '   Normal:   ( %16.8e %16.8e %16.8e )\n', normal )

            end

            start  = start  + nread;
            remain = remain - nread;

         end

         %
         % Close file.
         %
         cspice_dascls( handle )

   MATLAB outputs:

      >> dskz02_t('solid.bds' )

      Number of vertices:  12
      Number of plates:    20

      Plate number: 1
         Vertex 1: (   0.00000000e+00   0.00000000e+00   1.17557000e+00 )
         Vertex 2: (   1.05146000e+00   0.00000000e+00   5.25731000e-01 )
         Vertex 3: (   3.24920000e-01   1.00000000e+00   5.25731000e-01 )
         Normal:   (   4.91124160e-01   3.56821347e-01   7.94654382e-01 )

      Plate number: 2
         Vertex 1: (   0.00000000e+00   0.00000000e+00   1.17557000e+00 )
         Vertex 2: (   3.24920000e-01   1.00000000e+00   5.25731000e-01 )
         Vertex 3: (  -8.50651000e-01   6.18034000e-01   5.25731000e-01 )
         Normal:   (  -1.87592328e-01   5.77350079e-01   7.94654645e-01 )

           ...

      Plate number: 19
         Vertex 1: (  -3.24920000e-01  -1.00000000e+00  -5.25731000e-01 )
         Vertex 2: (   0.00000000e+00   0.00000000e+00  -1.17557000e+00 )
         Vertex 3: (   8.50651000e-01  -6.18034000e-01  -5.25731000e-01 )
         Normal:   (   1.87592328e-01  -5.77350079e-01  -7.94654645e-01 )

      Plate number: 20
         Vertex 1: (   8.50651000e-01  -6.18034000e-01  -5.25731000e-01 )
         Vertex 2: (   0.00000000e+00   0.00000000e+00  -1.17557000e+00 )
         Vertex 3: (   8.50651000e-01   6.18034000e-01  -5.25731000e-01 )
         Normal:   (   6.07061680e-01   0.00000000e+00  -7.94654715e-01 )

Particulars


   None.

Required Reading


   For important details concerning this module's function, please
   refer to the CSPICE routine dskp02_c.

   MICE.REQ
   DAS.REQ
   DSK.REQ

Version


   -Mice Version 1.0.0, 04-APR-2017, NJB (JPL), EDW (JPL), ML (JPL)

Index_Entries


   return specified plates from type 2 DSK segment


Wed Apr  5 18:00:31 2017