| pckcov_c |
|
Table of contents
Procedure
pckcov_c ( PCK coverage )
void pckcov_c ( ConstSpiceChar * pckfnm,
SpiceInt idcode,
SpiceCell * cover )
AbstractFind the coverage window for a specified reference frame in a specified binary PCK file. Required_ReadingCELLS DAF PCK TIME WINDOWS KeywordsORIENTATION TIME UTILITY Brief_I/OVARIABLE I/O DESCRIPTION -------- --- -------------------------------------------------- pckfnm I Name of PCK file. idcode I Class ID code of PCK reference frame. cover I-O Window giving coverage in `pckfnm' for `idcode'. Detailed_Input
pckfnm is the name of a binary PCK file.
idcode is the integer frame class ID code of a PCK reference
frame for which data are expected to exist in the
specified PCK file.
cover is an initialized SPICE window data structure. `cover'
optionally may contain coverage data on input; on output,
the data already present in `cover' will be combined with
coverage found for the reference frame designated by
`idcode' in the file `pckfnm'.
If `cover' contains no data on input, its size and
cardinality still must be initialized.
`cover' must be declared as a double precision SpiceCell.
CSPICE provides the following macro, which declares and
initializes the cell
SPICEDOUBLE_CELL ( cover, COVERSZ );
where COVERSZ is the maximum capacity of `cover'.
Detailed_Output
cover is a SPICE window data structure which represents the
merged coverage for the reference frame having frame
class ID `idcode'. This is the set of time intervals for
which data for `idcode' are present in the file `pckfnm',
merged with the set of time intervals present in `cover' on
input. The merged coverage is represented as the union of
one or more disjoint time intervals. The window `cover'
contains the pairs of endpoints of these intervals.
The interval endpoints contained in `cover' are ephemeris
times, expressed as seconds past J2000 TDB.
See the -Examples section below for a complete example
program showing how to retrieve the endpoints from `cover'.
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 PCK,
the error SPICE(INVALIDFILETYPE) is signaled by a routine in
the call tree of this routine.
4) If the PCK file cannot be opened or read, an error is signaled
by a routine in the call tree of this routine. The output
window will not be modified.
5) If the size of the output window argument `cover' is
insufficient to contain the actual number of intervals in the
coverage window for `idcode', an error is signaled by a routine
in the call tree of this routine.
6) If the `pckfnm' input string pointer is null, the error
SPICE(NULLPOINTER) is signaled.
7) If the `pckfnm' input string has zero length, the error
SPICE(EMPTYSTRING) is signaled.
8) If the `cover' cell argument has a type other than
SpiceDouble, the error SPICE(TYPEMISMATCH) is signaled.
FilesThis routine reads a PCK file. ParticularsThis routine provides an API via which applications can determine the coverage a specified PCK file provides for a specified PCK class reference frame. Examples
The numerical results shown for these examples 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 pckcov_c and the
related PCK utility pckfrm_c.
Display the coverage for each object in a specified PCK file.
Find the set of objects in the file; for each object, find
and display the coverage.
Example code begins here.
/.
Program pckcov_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 pckfnm [ FILSIZ ];
SpiceChar timstr [ TIMLEN ];
SpiceDouble b;
SpiceDouble e;
SpiceInt i;
SpiceInt j;
SpiceInt niv;
SpiceInt obj;
/.
Load a leapseconds kernel for output time conversion.
pckcov_c itself does not require a leapseconds kernel.
./
prompt_c ( "Name of leapseconds kernel > ", FILSIZ, lsk );
furnsh_c ( lsk );
/.
Get name of PCK file.
./
prompt_c ( "Name of PCK file > ", FILSIZ, pckfnm );
/.
Find the set of frames in the PCK file.
./
pckfrm_c ( pckfnm, &ids );
/.
We want to display the coverage for each frame. 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 frame.
Empty the coverage window each time so we don't
include data for the previous frame.
./
obj = SPICE_CELL_ELEM_I( &ids, i );
scard_c ( 0, &cover );
pckcov_c ( pckfnm, 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 frame %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 PCK file
named earth_720101_070426.bpc, the output was:
Name of leapseconds kernel > naif0012.tls
Name of PCK file > earth_720101_070426.bpc
========================================
Coverage for frame 3000
Interval: 0
Start: 1962 JAN 20 00:00:41.184 (TDB)
Stop: 2007 APR 26 00:01:05.185 (TDB)
2) Find the coverage for the frame designated by `idcode'
provided by the set of PCK files loaded via a metakernel.
Use the meta-kernel shown below to load the required SPICE
kernels.
KPL/MK
File name: pckcov_ex2.tm
This meta-kernel is intended to support operation of SPICE
example programs. The kernels shown here should not be
assumed to contain adequate or correct versions of data
required by SPICE-based user applications.
In order for an application to use this meta-kernel, the
kernels referenced here must be present in the user's
current working directory.
The names and contents of the kernels referenced
by this meta-kernel are as follows:
File name Contents
--------- --------
earth_720101_070426.bpc Earth historical
binary PCK
earth_070425_370426_predict.bpc Earth predicted
binary PCK
naif0012.tls Leapseconds
\begindata
KERNELS_TO_LOAD = ( 'earth_070425_370426_predict.bpc',
'earth_720101_070426.bpc',
'naif0012.tls' )
\begintext
End of meta-kernel.
Example code begins here.
/.
Program pckcov_ex2
./
#include <stdio.h>
#include "SpiceUsr.h"
int main()
{
/.
Local parameters
./
#define FILSIZ 256
#define LNSIZE 81
#define MAXCOV 100000
#define WINSIZ ( 2 * MAXCOV )
#define TIMLEN 51
/.
Local variables
./
SPICEDOUBLE_CELL ( cover, WINSIZ );
SpiceBoolean found;
SpiceChar file [ FILSIZ ];
SpiceChar idch [ LNSIZE ];
SpiceChar meta [ FILSIZ ];
SpiceChar source [ FILSIZ ];
SpiceChar timstr [ TIMLEN ];
SpiceChar type [ LNSIZE ];
SpiceDouble b;
SpiceDouble e;
SpiceInt count;
SpiceInt handle;
SpiceInt i;
SpiceInt idcode;
SpiceInt niv;
/.
Prompt for the metakernel name; load the metakernel.
The metakernel lists the PCK files whose coverage
for `idcode' we'd like to determine. The metakernel
must also specify a leapseconds kernel.
./
prompt_c ( "Name of metakernel > ", FILSIZ, meta );
furnsh_c ( meta );
/.
Get the ID code of interest.
./
prompt_c ( "Enter ID code > ", LNSIZE, idch );
prsint_c ( idch, &idcode );
/.
Find out how many kernels are loaded. Loop over the
kernels: for each loaded PCK file, add its coverage
for `idcode', if any, to the coverage window.
./
ktotal_c ( "PCK", &count );
for ( i = 0; i < count; i++ )
{
kdata_c ( i, "PCK", FILSIZ, LNSIZE, FILSIZ,
file, type, source, &handle, &found );
pckcov_c ( file, idcode, &cover );
}
/.
Display results.
Get the number of intervals in the coverage window.
./
niv = wncard_c ( &cover );
/.
Display a simple banner.
./
printf ( "\nCoverage for frame %d\n", (int)idcode );
/.
Convert the coverage interval start and stop times to TDB
calendar strings.
./
for ( i = 0; i < niv; i++ )
{
/.
Get the endpoints of the ith interval.
./
wnfetd_c ( &cover, i, &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)i,
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 meta-kernel named pckcov_ex2.tm provided
above to find the coverage window for the ITRF93 frame using
its ID code, "3000", the output was:
Name of metakernel > pckcov_ex2.tm
Enter ID code > 3000
Coverage for frame 3000
Interval: 0
Start: 1962 JAN 20 00:00:41.184 (TDB)
Stop: 2037 JUL 17 00:01:05.183 (TDB)
Restrictions
1) If an error occurs while this routine is updating the window
`cover', the window 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, 25-AUG-2021 (JDR)
Changed input argument name "pck" to "pckfnm" for consistency with other
routines.
Edited the header to comply with NAIF standard. Corrected short error
message in entries #2 and #3 in -Exceptions section. Added examples'
solution and meta-kernel for example #2.
Extended description of argument "cover" in -Detailed_Input to include
type and preferred declaration method.
Added entry #8 to -Exceptions section.
-CSPICE Version 1.0.2, 12-JUL-2016 (EDW)
Edit to example program to use "%d" with explicit casts
to int for printing SpiceInts with printf.
-CSPICE Version 1.0.1, 01-JUL-2014 (NJB)
Updated index entries.
-CSPICE Version 1.0.0, 30-NOV-2007 (NJB)
Index_Entriesget coverage window for binary PCK reference frame get coverage start and stop time for binary PCK frame |
Fri Dec 31 18:41:10 2021