| spkobj_c |
|
Table of contents
Procedure
spkobj_c ( SPK objects )
void spkobj_c ( ConstSpiceChar * spkfnm,
SpiceCell * ids )
AbstractFind the set of ID codes of all objects in a specified SPK file. Required_ReadingCELLS DAF NAIF_IDS SETS SPK KeywordsEPHEMERIS UTILITY Brief_I/OVARIABLE I/O DESCRIPTION -------- --- -------------------------------------------------- spkfnm I Name of SPK file. ids I-O Set of ID codes of objects in SPK file. Detailed_Input
spkfnm is the name of an SPK file.
ids is an initialized SPICE 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 `spkfnm'.
If `ids' contains no data on input, its size and
cardinality still must be initialized.
`ids' must be declared as an integer SpiceCell.
CSPICE provides the following macro, which declares and
initializes the cell
SPICEINT_CELL ( ids, IDSSZ );
where IDSSZ is the maximum capacity of `ids'.
Detailed_Output
ids is a SPICE 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 SPICE 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'.
ParametersNone. Exceptions
1) If the input file has transfer format, the error
SPICE(INVALIDFORMAT) is signaled by a routine in the call tree
of this routine.
2) If the input file is not a transfer file but has architecture
other than DAF, the error SPICE(INVALIDARCHTYPE) is signaled
by a routine in the call tree of this routine.
3) If the input file is a binary DAF file of type other than SPK,
the error SPICE(INVALIDFILETYPE) is signaled by a routine in
the call tree of this routine.
4) If the SPK file cannot be opened or read, an error is signaled
by a routine in the call tree of 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, an error is signaled by a routine in
the call tree of this routine.
6) If the `spkfnm' input string pointer is null, the error
SPICE(NULLPOINTER) is signaled.
7) If the `spkfnm' input string has zero length, the error
SPICE(EMPTYSTRING) is signaled.
8) If the `ids' cell argument has a type other than SpiceInt, the
error SPICE(TYPEMISMATCH) is signaled.
FilesThis routine reads an SPK file. ParticularsThis 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
The numerical results shown for this example may differ across
platforms. The results depend on the SPICE kernels used as
input, the compiler and supporting libraries, and the machine
specific arithmetic implementation.
1) This example demonstrates combined usage of spkobj_c and the
related SPK utility spkcov_c.
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.
Example code begins here.
/.
Program spkobj_ex1
./
#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 spkfnm [ 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_c 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, spkfnm );
/.
Find the set of objects in the SPK file.
./
spkobj_c ( spkfnm, &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 ( spkfnm, 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 %d\n", (int)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: %d\n"
"Start: %s\n",
(int)j,
timstr );
timout_c ( e,
"YYYY MON DD HR:MN:SC.### (TDB) ::TDB",
TIMLEN,
timstr );
printf ( "Stop: %s\n", timstr );
}
}
return ( 0 );
}
When this program was executed on a Mac/Intel/cc/64-bit
platform, using the LSK file named naif0012.tls and the SPK
file named mar097.bsp, the output was:
Name of leapseconds kernel > naif0012.tls
Name of SPK file > mar097.bsp
========================================
Coverage for object 3
Interval: 0
Start: 1900 JAN 04 00:00:41.184 (TDB)
Stop: 2100 JAN 01 00:01:07.183 (TDB)
========================================
Coverage for object 4
Interval: 0
Start: 1900 JAN 04 00:00:41.184 (TDB)
Stop: 2100 JAN 01 00:01:07.183 (TDB)
========================================
Coverage for object 10
Interval: 0
Start: 1900 JAN 04 00:00:41.184 (TDB)
Stop: 2100 JAN 01 00:01:07.183 (TDB)
========================================
Coverage for object 399
Interval: 0
Start: 1900 JAN 04 00:00:41.184 (TDB)
Stop: 2100 JAN 01 00:01:07.183 (TDB)
========================================
Coverage for object 401
Interval: 0
Start: 1900 JAN 04 00:00:41.184 (TDB)
Stop: 2100 JAN 01 00:01:07.183 (TDB)
========================================
Coverage for object 402
Interval: 0
Start: 1900 JAN 04 00:00:41.184 (TDB)
Stop: 2100 JAN 01 00:01:07.183 (TDB)
========================================
Coverage for object 499
Interval: 0
Start: 1900 JAN 04 00:00:41.184 (TDB)
Stop: 2100 JAN 01 00:01:07.183 (TDB)
Restrictions
1) If an error occurs while this routine is updating the set
`ids', the set may be corrupted.
Literature_ReferencesNone. Author_and_InstitutionN.J. Bachman (JPL) J. Diaz del Rio (ODC Space) E.D. Wright (JPL) Version
-CSPICE Version 1.1.0, 24-AUG-2021 (JDR)
Changed input argument name "spk" to "spkfnm" for consistency with other
routines.
Edited the header to comply with NAIF standard. Added example's
solution. Corrected short error message in entries #2 and #3 in
-Exceptions section and added entry #8.
Added NAIF_IDS to -Required_Reading section.
Extended description of argument "ids" in -Detailed_Input to include
type and preferred declaration method.
-CSPICE Version 1.0.3, 14-JUN-2016 (EDW)
Edit to example program to use "%d" with explicit casts
to int for printing SpiceInts with printf.
-CSPICE Version 1.0.2, 01-JUL-2014 (NJB)
Updated index entries.
-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_Entriesfind id codes of ephemeris objects in SPK file find id codes of bodies in SPK file |
Fri Dec 31 18:41:12 2021