| pckw02_c |
|
Table of contents
Procedure
pckw02_c ( PCK, write type 2 segment )
void pckw02_c ( SpiceInt handle,
SpiceInt clssid,
ConstSpiceChar * frame,
SpiceDouble first,
SpiceDouble last,
ConstSpiceChar * segid,
SpiceDouble intlen,
SpiceInt n,
SpiceInt polydg,
SpiceDouble cdata [],
SpiceDouble btime )
AbstractWrite a type 2 segment to a PCK binary file given the file handle, frame class ID, base frame, time range covered by the segment, and the Chebyshev polynomial coefficients. Required_ReadingDAF FRAMES NAIF_IDS PCK SPC KeywordsPCK Brief_I/OVARIABLE I/O DESCRIPTION -------- --- -------------------------------------------------- handle I Handle of binary PCK file open for writing. clssid I Frame class ID of body-fixed frame. frame I Name of base reference frame. first I Start time of interval covered by segment. last I End time of interval covered by segment. segid I Segment identifier. intlen I Length of time covered by logical record. n I Number of logical records in segment. polydg I Chebyshev polynomial degree. cdata I Array of Chebyshev coefficients. btime I Begin time of first logical record. Detailed_Input
handle is the DAF handle of an PCK file to which a type 2
segment is to be added. The PCK file must be open
for writing.
clssid is the frame class ID of a body-fixed reference frame
whose orientation is described by the segment to be
created.
frame is the NAIF name for a reference frame relative to
which the orientation information for the frame
designated by `clssid' is specified. The frame
designated by `frame' is called the "base frame."
first,
last are, respectively, the start and stop times of
the time interval over which the segment defines
the orientation of clssid.
segid is the segment identifier. A PCK segment
identifier may contain up to 40 characters.
intlen Length of time, in seconds, covered by each set of
Chebyshev polynomial coefficients (each logical
record). Each set of Chebyshev coefficients must
cover this fixed time interval, `intlen'.
n is the number of sets of Chebyshev polynomial
coefficients (number of logical records)
to be stored in the segment. There is one set
of Chebyshev coefficients for each time interval.
polydg Degree of each set of Chebyshev polynomials.
cdata Array containing all the sets of Chebyshev
polynomial coefficients to be contained in the
segment of the PCK file. The coefficients are
stored in cdata in order as follows:
the (degree + 1) coefficients for the first
Euler angle of the first logical record
the coefficients for the second Euler angle
the coefficients for the third Euler angle
the coefficients for the first Euler angle for
the second logical record, ...
and so on.
btime Begin time (seconds past J2000 TDB) of first set
of Chebyshev polynomial coefficients (first
logical record).
Detailed_OutputNone. ParametersNone. Exceptions
1) If the number of sets of coefficients is not positive, the
error SPICE(NUMCOEFFSNOTPOS) is signaled by a routine in the
call tree of this routine.
2) If the interval length is not positive, the error
SPICE(INTLENNOTPOS) is signaled by a routine in the call tree
of this routine.
3) If the integer code for the reference frame is not recognized,
the error SPICE(INVALIDREFFRAME) is signaled by a routine in
the call tree of this routine.
4) If segment stop time is not greater then the begin time, the
error SPICE(BADDESCRTIMES) is signaled by a routine in the
call tree of this routine.
5) If the time of the first record is not greater than or equal
to the descriptor begin time, the error SPICE(BADDESCRTIMES)
is signaled by a routine in the call tree of this routine.
6) If the end time of the last record is not greater than or
equal to the descriptor end time, the error
SPICE(BADDESCRTIMES) is signaled by a routine in the call tree
of this routine.
7) If any of the `frame' or `segid' input string pointers is
null, the error SPICE(NULLPOINTER) is signaled.
8) If any of the `frame' or `segid' input strings has zero
length, the error SPICE(EMPTYSTRING) is signaled.
FilesA new type 2 PCK segment is written to the PCK file attached to HANDLE. ParticularsThis routine writes an PCK type 2 data segment to the designated PCK file, according to the format described in the PCK Required Reading. Each segment can contain data for only one body-fixed frame and base reference frame. The Chebyshev polynomial degree and length of time covered by each logical record are also fixed. However, an arbitrary number of logical records of Chebyshev polynomial coefficients can be written in each segment. Minimizing the number of segments in a PCK file will help optimize how the SPICE system accesses the 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) Suppose that you have sets of Chebyshev polynomial
coefficients in an array pertaining to the orientation of
the Moon body-fixed frame with the frame class ID 301
relative to the J2000 reference frame, and want
to put these into a type 2 segment PCK file. The following
example could be used to add one new type 2 segment. To add
multiple segments, put the call to pckw02_c in a loop.
Example code begins here.
/.
Program pckw02_ex1
./
#include "SpiceUsr.h"
int main( )
{
/.
Local parameters
./
#define FNAME "pckw02_ex1.bpc"
#define BODY 301
#define POLYDG 9
#define SZCDAT 60
/.
Local variables
./
SpiceChar * ifname;
SpiceChar * segid;
SpiceDouble btime;
SpiceDouble first;
SpiceDouble intlen;
SpiceDouble last;
SpiceInt handle;
SpiceInt n;
SpiceInt nresvc;
/.
Set the input data: RA/DEC/W coefficients,
begin time for the first record, start/end times
for the segment, length of the time covered by
each record, and number of logical records.
`cdata' contains the ra/dec/w coefficients: first the
the polydeg + 1 for the RA first record, then the
polydeg + 1 for the DEC first record, then the
polydeg +1 for W first record, then the polydeg + 1
for the RA second record, and so on.
./
SpiceDouble cdata [SZCDAT] = {
-5.4242086033301107e-002, -5.2241405162792561e-005,
8.9751456289930307e-005, -1.5288696963234620e-005,
1.3218870864581395e-006, 5.9822156790328180e-007,
-6.5967702052551211e-008, -9.9084309118396298e-009,
4.9276055963541578e-010, 1.1612267413829385e-010,
0.42498898565916610, 1.3999219324235620e-004,
-1.8855140511098865e-005, -2.1964684808526649e-006,
1.4229817868138752e-006, -1.6991716166847001e-007,
-3.4824688140649506e-008, 2.9208428745895990e-009,
4.4217757657060300e-010, -3.9211207055305402e-012,
2565.0633504619473, 0.92003769451305328,
-8.0503797901914501e-005, 1.1960860244433900e-005,
-1.2237900518372542e-006, -5.3651349407824562e-007,
6.0843372260403005e-008, 9.0211287487688797e-009,
-4.6460429330339309e-010, -1.0446918704281774e-010,
-5.3839796353225056e-002, 4.3378021974424991e-004,
4.8130091384819459e-005, -1.2283066272873327e-005,
-5.4099296265403208e-006, -4.4237368347319652e-007,
1.3004982445546169e-007, 1.9017128275284284e-008,
-7.0368223839477803e-011, -1.7119414526133175e-010,
0.42507987850614548, -7.1844899448557937e-005,
-5.1052122872412865e-005, -8.9810401387721321e-006,
-1.4611718567948972e-007, 4.0883847771062547e-007,
4.6812854485029333e-008, -4.5698075960784951e-009,
-9.8679875320349531e-010, -7.9392503778178240e-011,
2566.9029069934054, 0.91952244801740568,
-6.0426151041179828e-005, 1.0850559330577959e-005,
5.1756033678137497e-006, 4.2127585555214782e-007,
-1.1774737441872970e-007, -1.7397191490163833e-008,
5.8908810244396165e-012, 1.4594279337955166e-010 };
first = -43200.0;
last = 1339200.0;
btime = first;
intlen = 691200.0;
n = 2;
/.
Open a new PCK file. For simplicity, we will not
reserve any space for the comment area, so the
number of reserved comment characters is zero.
The variable `ifname' is the internal file name.
./
nresvc = 0;
ifname = "Test PCK/Created 04-SEP-2019";
pckopn_c ( FNAME, ifname, nresvc, &handle );
/.
Create a segment identifier.
./
segid = "MY_SAMPLE_PCK_TYPE_2_SEGMENT";
/.
Write the segment.
./
pckw02_c ( handle, BODY, "J2000", first, last, segid,
intlen, n, POLYDG, cdata, btime );
/.
Close the file.
./
pckcls_c ( handle );
return ( 0 );
}
When this program is executed, no output is presented on
screen. After run completion, a new PCK type 2 exists in
the output directory.
RestrictionsNone. Literature_ReferencesNone. Author_and_InstitutionN.J. Bachman (JPL) J. Diaz del Rio (ODC Space) K.S. Zukor (JPL) Version
-CSPICE Version 1.0.1, 04-AUG-2021 (JDR)
Edited the header to comply with NAIF standard. Added
complete code examples based on existing fragment.
-CSPICE Version 1.0.0, 16-DEC-2016 (NJB) (KSZ)
Index_Entrieswrite PCK type_2 data segment |
Fri Dec 31 18:41:10 2021