spkobj_c

Index Page spkobj_c
A B C D E F G H I J K L M N O P Q R S T U V W X
Procedure Abstract Required_Reading Keywords Brief_I/O Detailed_Input | Detailed_Output Parameters Exceptions Files Particulars Examples | Restrictions Literature_References Author_and_Institution Version Index_Entries
#### Procedure
       void spkobj_c ( ConstSpiceChar  * spk,
                       SpiceCell       * ids )
#### Abstract
       Find the set of ID codes of all objects in a specified SPK file.
#### Required_Reading
       CELLS
       DAF
       SETS
       SPK
#### Keywords
       EPHEMERIS
       UTILITY
#### Brief_I/O
       Variable  I/O  Description
       --------  ---  --------------------------------------------------
       spk        I   Name of SPK file.
       ids       I/O  Set of ID codes of objects in SPK file.
#### Detailed_Input
       spk            is the name of an SPK file.

       ids            is an initialized CSPICE set data structure.
                      `ids' optionally may contain a set of ID codes on
                      input; on output, the data already present in
                      `ids' will be combined with ID code set found for the
                      file `spk'.

                      If `ids' contains no data on input, its size and
                      cardinality still must be initialized.
#### Detailed_Output
       ids            is a CSPICE set data structure which contains
                      the union of its contents upon input with the set
                      of ID codes of each object for which ephemeris
                      data are present in the indicated SPK file. The
                      elements of CSPICE sets are unique; hence each
                      ID code in `ids' appears only once, even if the SPK
                      file contains multiple segments for that ID code.

                      See the Examples section below for a complete
                      example program showing how to retrieve the ID
                      codes from `ids'.
#### Parameters
       None.
#### Exceptions
       1)  If the input file has transfer format, the error
           SPICE(INVALIDFORMAT) is signaled.

       2)  If the input file is not a transfer file but has architecture
           other than DAF, the error SPICE(BADARCHTYPE) is signaled.

       3)  If the input file is a binary DAF file of type other than
           SPK, the error SPICE(BADFILETYPE) is signaled.

       4)  If the SPK file cannot be opened or read, the error will
           be diagnosed by routines called by this routine.

       5)  If the size of the output set argument `ids' is insufficient to
           contain the actual number of ID codes of objects covered by
           the indicated SPK file, the error will be diagnosed by
           routines called by this routine.

       6) The error SPICE(EMPTYSTRING) is signaled if the input
          string `spk' does not contain at least one character, since the
          input string cannot be converted to a Fortran-style string in
          this case.

       7) The error SPICE(NULLPOINTER) is signaled if the input string
          pointer `spk' is null.
#### Files
       This routine reads an SPK file.
#### Particulars
       This routine provides an API via which applications can determine
       the set of objects for which there are ephemeris data in a
       specified SPK file.
#### Examples
       1)  Display the coverage for each object in a specified SPK file.
           Find the set of objects in the file.  Loop over the contents
           of the ID code set:  find the coverage for each item in the
           set and display the coverage.

              #include <stdio.h>
              #include "SpiceUsr.h"

              int main()
              {
                 /.
                 Local parameters
                 ./
                 #define  FILSIZ         256
                 #define  MAXIV          1000
                 #define  WINSIZ         ( 2 * MAXIV )
                 #define  TIMLEN         51
                 #define  MAXOBJ         1000

                 /.
                 Local variables
                 ./
                 SPICEDOUBLE_CELL        ( cover, WINSIZ );
                 SPICEINT_CELL           ( ids,   MAXOBJ );

                 SpiceChar               lsk     [ FILSIZ ];
                 SpiceChar               spk     [ FILSIZ ];
                 SpiceChar               timstr  [ TIMLEN ];

                 SpiceDouble             b;
                 SpiceDouble             e;

                 SpiceInt                i;
                 SpiceInt                j;
                 SpiceInt                niv;
                 SpiceInt                obj;

                 /.
                 Load a leapseconds kernel for output time conversion.
                 SPKCOV itself does not require a leapseconds kernel.
                 ./
                 prompt_c ( "Name of leapseconds kernel > ", FILSIZ, lsk );
                 furnsh_c ( lsk );

                 /.
                 Get name of SPK file.
                 ./
                 prompt_c ( "Name of SPK file           > ", FILSIZ, spk    );

                 /.
                 Find the set of objects in the SPK file.
                 ./
                 spkobj_c ( spk, &ids );

                 /.
                 We want to display the coverage for each object. Loop over
                 the contents of the ID code set, find the coverage for
                 each item in the set, and display the coverage.
                 ./
                 for ( i = 0;  i < card_c( &ids );  i++  )
                 {
                    /.
                    Find the coverage window for the current object.
                    Empty the coverage window each time so we don't
                    include data for the previous object.
                    ./
                    obj  =  SPICE_CELL_ELEM_I( &ids, i );

                    scard_c  ( 0,        &cover );
                    spkcov_c ( spk, obj, &cover );

                    /.
                    Get the number of intervals in the coverage window.
                    ./
                    niv = wncard_c ( &cover );

                    /.
                    Display a simple banner.
                    ./
                    printf ( "%s\n", "========================================" );

                    printf ( "Coverage for object %ld\n", obj );

                    /.
                    Convert the coverage interval start and stop times to TDB
                    calendar strings.
                    ./
                    for ( j = 0;  j < niv;  j++  )
                    {
                       /.
                       Get the endpoints of the jth interval.
                       ./
                       wnfetd_c ( &cover, j, &b, &e );

                       /.
                       Convert the endpoints to TDB calendar
                       format time strings and display them.
                       ./
                       timout_c ( b,
                                  "YYYY MON DD HR:MN:SC.### (TDB) ::TDB",
                                  TIMLEN,
                                  timstr                                  );

                       printf ( "\n"
                                "Interval:  %ld\n"
                                "Start:     %s\n",
                                j,
                                timstr            );

                       timout_c ( e,
                                  "YYYY MON DD HR:MN:SC.### (TDB) ::TDB",
                                  TIMLEN,
                                  timstr                                  );
                       printf ( "Stop:      %s\n", timstr );

                    }

                 }
                 return ( 0 );
              }
#### Restrictions
       1) If an error occurs while this routine is updating the set
          `ids', the set may be corrupted.
#### Literature_References
       None.
#### Author_and_Institution
       N.J. Bachman   (JPL)
#### Version
       -CSPICE Version 1.0.1, 30-NOV-2007 (NJB)

           Corrected bug in first example program in header:
           program now empties result window prior to collecting
           data for each object. Deleted declaration of unused
           constant NAMLEN.  Updated example to use wncard_c
           rather than card_c.

       -CSPICE Version 1.0.0, 30-DEC-2004 (NJB)
#### Index_Entries
       find id codes in spk file
#### Link to routine spkobj_c source file spkobj_c.c

    Thu Apr 16 08:59:14 2009