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Abstract
I/O
Examples
Particulars
Required Reading
Version
Index_Entries

Abstract


   CSPICE_DSKMI2 makes a spatial index for type 2 DSK segment.

I/O


   Given:

      vrtces      is an array of coordinates of the vertices. The Ith
                  vertex occupies elements [1:3,I] of this array.

                  [3,m] = size(vrtces); double = class(vrtces)

      plates      is an array representing the triangular plates of a
                  shape model. The elements of `plates' are vertex
                  indices; vertex indices are 1-based. The vertex
                  indices of the Ith plate occupy elements [1:3,I] of
                  this array.

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

      finscl      is the fine voxel scale.

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

                  This scale determines the edge length of the cubical
                  voxels comprising the fine voxel grid: the edge length
                  `voxsiz' is approximately

                      finscl * {average plate extent}

                  where the extents of a plate are the respective
                  differences between the maximum and minimum
                  coordinate values of the plate's vertices.

                  The relationship between `voxsiz' and the average plate
                  extent is approximate because the `voxsiz' is adjusted
                  so that each dimension of the fine voxel grid is an
                  integer multiple of the coarse voxel scale.

                  See the Particulars section below for further
                  information on voxel scales.

      corscl      is the coarse voxel scale. This integer scale is the
                  ratio of the edge length of coarse voxels to that of
                  fine voxels. The coarse scale must be large enough so
                  that the total number of coarse voxels does not exceed
                  SPICE_DSK02_MAXCGR (see DSKMice02.m).

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

      worksz      is the second dimension of the workspace array `work'.

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

                  `worksz' must be at least as large as the greater of

                     - the number of fine voxel-plate associations

                       This number is equal to

                          np * {average number of fine voxels
                                intersected by each plate}

                     - the number of vertex-plate associations, if
                       the vertex-plate mapping is constructed.

                       This number is equal to

                          nv + ( 3 * np )

      voxpsz      is the size of the fine voxel-plate pointer array.

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

                  This array maps fine voxels to lists of plates that
                  intersect those voxels. `voxpsz' must be at least as
                  large as

                           3
                     corscl  * {number of non-empty coarse voxels}

      voxlsz      is the size of the fine voxel-plate list array.

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

                  This array contains, for each non-empty fine voxel, the
                  count of plates that intersect that voxel and the
                  IDs of those plates. `voxlsz' must be at least as large
                  as

                          `np' * {average number of fine voxels
                                intersected by each plate}

                      +   {number of non-empty fine voxels}

      makvtl      is a logical flag that, when set to true, indicates
                  that a  vertex-plate association list is to be
                  constructed.

                  [1,1] = size(makvtl); logical = class(makvtl)

                  The amount of workspace that is needed may depend on
                  whether a vertex-plate association list is
                  constructed. When this list is constructed, the size
                  of the integer component of the spatial index is
                  increased by the size of the list and the size of a
                  vertex-plate pointer array; the total of these sizes
                  is

                     ( 2 * nv ) + ( 3 * np )

      spxisz      is the declared size of the output array SPAIXI.

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

                   This size must be at least as large as the sum of

                     - the fixed-size part of the integer component of
                       the index, which includes the coarse voxel grid;
                       this value is

                          SPICE_DSK02_IDXFIX

                     - the size `voxpsz' of the voxel-plate pointer array

                     - the size `voxlsz' of the voxel-plate association
                       list

                  plus, if the vertex-plate association list is
                  constructed,

                     - the size `nv' of the vertex-plate pointer array

                     - the size of the vertex-plate association list;
                       this size is

                          nv + ( 3 * np )

   the call:

      [spaixd, spaixi] = cspice_dskmi2( vrtces, plates, finscl, ...
                                        corscl, worksz, voxpsz, ...
                                        voxlsz, makvtl,         ...
                                        spaisz );

   returns:

      spaixd,
      spaixi      are, respectively, the double precision and integer
                  components of the spatial index of the segment.

                  [p,1] = size(spaixd); double = class(spaixd)
                  [q,1] = size(spaixi); int32 = class(spaixi)

                  `spaixd' must be declared with size at least
                  SPICE_DSK02_IXDFIX.

                  `spaixi' must be declared with size at least `spxisz'.

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.

   Example(1):

      function dskmi2_t

         %
         % MiceUser globally defines DSK parameters.
         % For more information, please see DSKMiceUser.m and
         % DSKMice02.m.
         %
         MiceUser

         NSEG = 3;

         cornam = { 'radius', 'Z-coordinate', 'Z-coordinate', 'altitude'};

         %
         % Assign names of input and output DSK files.
         %
         indsk = '/kernels/gen/dsk/phobos_3_3.bds';
         dsk   = 'phobos_3_3_3seg.bds';

         if ( exist( dsk, 'file' ) == 2 )
            delete( dsk )
         end


         %
         % Open input DSK for read access; find first segment.
         %
         inhan           = cspice_dasopr( indsk );
         [dladsc, found] = cspice_dlabfs( inhan );


         %
         % Fetch vertices and plates from input DSK file.
         %
         % Note that vertex and plate indices are 1-based.
         %
         disp( 'Reading input data...' )

         vrtces = cspice_dskv02( inhan, dladsc, 1, SPICE_DSK02_MAXVRT );
         plates = cspice_dskp02( inhan, dladsc, 1, SPICE_DSK02_MAXPLT );

         disp( 'Done.' )


         %
         % Set input array sizes required by cspice_dskmi2.
         %
         voxpsz = SPICE_DSK02_MAXVXP;
         voxlsz = SPICE_DSK02_MXNVLS;
         worksz = SPICE_DSK02_MAXCEL;
         spaisz = SPICE_DSK02_SPAISZ;
         makvtl = true;

         %
         % Set fine and coarse voxel scales. (These usually
         % need to determined by experimentation.)
         %
         finscl = 5.0;
         corscl = 4;

         %
         % Open a new DSK file.
         %
         handle = cspice_dskopn( dsk, dsk, 0 );

         for segno=1:NSEG

            %
            % Create spatial index. We won't generate a
            % vertex-plate mapping, so we set the flag
            % for creating this map to "false."
            %
            fprintf( 'Creating segment %d\n', segno )
            fprintf( 'Creating spatial index...\n' )

            [spaixd, spaixi] = cspice_dskmi2( vrtces, plates, finscl, ...
                                              corscl, worksz, voxpsz, ...
                                              voxlsz, makvtl,         ...
                                              spaisz );

            fprintf( 'Done.\n')

            %
            % Set up inputs describing segment attributes:
            %
            % - Central body: Phobos
            % - Surface ID code: user's choice.
            %   We use the segment number here.
            % - Data class: general (arbitrary) shape
            % - Body-fixed reference frame
            % - Time coverage bounds (TBD)
            %
            center = 401;
            surfid = segno;
            dclass = SPICE_DSK_GENCLS;
            frame  = 'IAU_PHOBOS';

            first = -50. * cspice_jyear();
            last  =  50. * cspice_jyear();

            %
            % Set the coordinate system and coordinate system
            % bounds based on the segment index.
            %
            % Zero out the coordinate parameters to start.
            %
            corpar = zeros(SPICE_DSK_NSYPAR,1);

            switch segno

               case 1

                  %
                  % Use planetocentric latitudinal coordinates. Set
                  % the longitude and latitude bounds.
                  %
                  corsys = SPICE_DSK_LATSYS;

                  mncor1 = -cspice_pi();
                  mxcor1 =  cspice_pi();
                  mncor2 = -cspice_halfpi();
                  mxcor2 =  cspice_halfpi();

               case 2

                  %
                  % Use rectangular coordinates. Set the
                  % X and Y bounds.
                  %
                  % The bounds shown here were derived from
                  % the plate data. They lie slightly outside
                  % of the range spanned by the plates.
                  %
                  corsys = SPICE_DSK_RECSYS;

                  mncor1 = -1.3;
                  mxcor1 =  1.31;
                  mncor2 = -1.21;
                  mxcor2 =  1.2;

               case 3

                  %
                  % Set the coordinate system to planetodetic.
                  %
                  corsys    = SPICE_DSK_PDTSYS;

                  mncor1    = -cspice_pi();
                  mxcor1    =  cspice_pi();
                  mncor2    = -cspice_halfpi();
                  mxcor2    =  cspice_halfpi();

                  %
                  % We'll use equatorial and polar radii from
                  % pck00010.tpc. These normally would be fetched
                  % at run time, but for simplicity, we'll use
                  % hard-coded values.
                  %
                  re        = 13.0;
                  rp        =  9.1;
                  f         = ( re - rp ) / re;

                  corpar = [ re, f ]';

               otherwise

                  error( 'Mice(BUG)' )

            end

            %
            % Compute plate model radius bounds.
            %
            fprintf( 'Computing %s bounds of plate set...\n', ...
                                            char(cornam(corsys)) )

            [mncor3, mxcor3] = cspice_dskrb2( vrtces, plates, corsys, corpar );

            fprintf ( 'Done.\n' )

            %
            % Write the segment to the file.
            %
            fprintf( 'Writing segment...\n' )

            cspice_dskw02( handle, ...
                              center, ...
                              surfid, ...
                              dclass, ...
                              frame,  ...
                              corsys, ...
                              corpar, ...
                              mncor1, ...
                              mxcor1, ...
                              mncor2, ...
                              mxcor2, ...
                              mncor3, ...
                              mxcor3, ...
                              first,  ...
                              last,   ...
                              vrtces, ...
                              plates, ...
                              spaixd,  ...
                              spaixi )

         end

         cspice_dascls( inhan )
         cspice_dskcls( handle, true )

         %
         % Close the input DSK.
         %
         cspice_dascls( inhan )

   MATLAB outputs:

      Reading input data...
      Done.
      Creating segment 1
      Creating spatial index...
      Done.
      Computing radius bounds of plate set...
      Done.
      Writing segment...
      Creating segment 2
      Creating spatial index...
      Done.
      Computing Z-coordinate bounds of plate set...
      Done.
      Writing segment...
      Creating segment 3
      Creating spatial index...
      Done.
      Computing altitude bounds of plate set...
      Done.
      Writing segment...

      After run completion, A DSK exists in the output directory.

Particulars


   None.

Required Reading


   For important details concerning this module's function, please refer to
   the CSPICE routine dskmi2_c.

   MICE.REQ
   DAS.REQ
   DSK.REQ

Version


   -Mice Version 1.0.0, 04-FEB-2016, EDW (JPL), NJB (JPL)

Index_Entries


   make spatial index for type 2 dsk segment


Wed Apr  5 18:00:30 2017