void pckw02_c ( SpiceInt handle,
ConstSpiceChar * frame,
ConstSpiceChar * segid,
SpiceDouble cdata ,
SpiceDouble btime )
Write 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.
Variable 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.
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
clssid is the frame class ID of a body-fixed reference frame
whose orientation is described by the segment to be
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."
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
1) If the number of sets of coefficients is not positive
SPICE(NUMCOEFFSNOTPOS) is signaled.
2) If the interval length is not positive, SPICE(INTLENNOTPOS)
3) If the integer code for the reference frame is not recognized,
SPICE(INVALIDREFFRAME) is signaled.
4) If segment stop time is not greater then the begin time,
SPICE(BADDESCRTIMES) is signaled.
5) If the time of the first record is not greater than
or equal to the descriptor begin time, SPICE(BADDESCRTIMES)
6) If the end time of the last record is not greater than
or equal to the descriptor end time, SPICE(BADDESCRTIMES) is
7) If any input string pointers are null, the error
SPICE(NULLPOINTER) will be signaled.
8) If any input strings have length zero, the error
SPICE(EMPTYSTRING) will be signaled.
A new type 2 PCK segment is written to the PCK file attached
This routine writes an PCK type 2 data segment to the designated
PCK file, according to the format described in the PCK Required
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.
Suppose that you have sets of Chebyshev polynomial coefficients
in an array `cdata' pertaining to the position of the moon (NAIF ID
= 301) in the J2000 reference frame, and want to put these into a
type 2 segment in an existing PCK file. The following code could
be used to add one new type 2 segment. To add multiple segments,
put the call to pckw02_c in a loop.
First open the PCK file and get a handle for it.
dafopw_c ( pcknam, &handle );
Create a segment identifier.
segid = "MY_SAMPLE_PCK_TYPE_2_SEGMENT";
Write the segment.
pckw02_c ( handle, 301, "j2000",
first, last, segid, intlen,
n, polydg, cdata, btime );
Close the file.
pckcls_c ( handle );
N.J. Bachman (JPL)
K.S. Zukor (JPL)
-CSPICE Version 1.0.0, 16-DEC-2016 (NJB) (KSZ)
write pck type_2 data segment