Index of Functions: A B C D E F G H I J K L M N O P Q R S T U V W X
Index Page spk14b_c

Table of contents

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

       spk14b_c ( SPK, begin a type 14 segment )

       void spk14b_c (  SpiceInt           handle,
                        ConstSpiceChar   * segid,
                        SpiceInt           body,
                        SpiceInt           center,
                        ConstSpiceChar   * frame,
                        SpiceDouble        first,
                        SpiceDouble        last,
                        SpiceInt           chbdeg  )

#### Abstract

       Begin a type 14 SPK segment in the SPK file associated with
       `handle'.

#### Required_Reading

       SPK

#### Keywords

       SPK

#### Brief_I/O

       VARIABLE  I/O  DESCRIPTION
       --------  ---  --------------------------------------------------
       handle     I   The handle of an SPK file open for writing.
       segid      I   The string to use for segment identifier.
       body       I   The NAIF ID code for the body of the segment.
       center     I   The center of motion for body.
       frame      I   The reference frame for this segment.
       first      I   The first epoch for which the segment is valid.
       last       I   The last epoch for which the segment is valid.
       chbdeg     I   The degree of the Chebyshev Polynomial used.

#### Detailed_Input

       handle      is the file handle of an SPK file that has been
                   opened for writing.

       segid       is the segment identifier. An SPK segment identifier
                   may contain up to 40 printing ASCII characters.

       body        is the NAIF ID for the body whose states are
                   to be recorded in an SPK file.

       center      is the NAIF ID for the center of motion associated
                   with body.

       frame       is the reference frame that states are referenced to,
                   for example "J2000".

       first       is the starting epoch, in TDB seconds past J2000, for
                   the ephemeris data to be placed into the segment.

       last        is the ending epoch, in TDB seconds past J2000, for
                   the ephemeris data to be placed into the segment.

       chbdeg      is the degree of the Chebyshev Polynomials used to
                   represent the ephemeris information stored in the
                   segment.

#### Detailed_Output

       None.

       The input data is used to create the segment summary for the segment
       being started in the SPK file associated with `handle'.

       See the -Particulars section for details about the structure of a
       type 14 SPK segment.

#### Parameters

       None.

#### Exceptions

       1)  If the degree of the Chebyshev Polynomial to be used for this
           segment is negative, the error SPICE(INVALIDARGUMENT) is
           signaled by a routine in the call tree of this routine.

       2)  If there are issues in the structure or content of the inputs
           other than the degree of the Chebyshev Polynomial, an error is
           signaled by a routine in the call tree of this routine.

       3)  If a file access error occurs, the error is signaled by a
           routine in the call tree of this routine.

       4)  If any of the `frame' or `segid' input string pointers is
           null, the error SPICE(NULLPOINTER) is signaled.

       5)  If any of the `frame' or `segid' input strings has zero
           length, the error SPICE(EMPTYSTRING) is signaled.

#### Files

       See handle in the -Detailed_Input section.

#### Particulars

       This routine begins writing a type 14 SPK segment to the open SPK
       file that is associated with `handle'. The file must have been
       opened with write access.

       This routine is one of a set of three routines for creating and
       adding data to type 14 SPK segments. These routines are:

          spk14b_c: Begin a type 14 SPK segment. This routine must be
                    called before any data may be added to a type 14
                    segment.

          spk14a_c: Add data to a type 14 SPK segment. This routine may be
                    called any number of times after a call to spk14b_c to
                    add type 14 records to the SPK segment that was
                    started.

          spk14e_c: End a type 14 SPK segment. This routine is called to
                    make the type 14 segment a permanent addition to the
                    SPK file. Once this routine is called, no further type
                    14 records may be added to the segment. A new segment
                    must be started.

       A type 14 SPK segment consists of coefficient sets for fixed order
       Chebyshev polynomials over consecutive time intervals, where the
       time intervals need not all be of the same length. The Chebyshev
       polynomials represent the position, X, Y, and Z coordinates, and
       the velocities, dX/dt, dY/dt, and dZ/dt, of body relative to
       center.

       The ephemeris data supplied to the type 14 SPK writer is packed
       into an array as a sequence of records,

          -----------------------------------------------------
          | Record 1 | Record 2 | ... | Record N-1 | Record N |
          -----------------------------------------------------

       with each record has the following format.

             ------------------------------------------------
             |  The midpoint of the approximation interval  |
             ------------------------------------------------
             |  The radius of the approximation interval    |
             ------------------------------------------------
             |  chbdeg+1 coefficients for the X coordinate  |
             ------------------------------------------------
             |  chbdeg+1 coefficients for the Y coordinate  |
             ------------------------------------------------
             |  chbdeg+1 coefficients for the Z coordinate  |
             ------------------------------------------------
             |  chbdeg+1 coefficients for the X velocity    |
             ------------------------------------------------
             |  chbdeg+1 coefficients for the Y velocity    |
             ------------------------------------------------
             |  chbdeg+1 coefficients for the Z velocity    |
             ------------------------------------------------

#### 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 how to create an SPK type 14 kernel
          containing only one segment, given a set of Chebyshev
          coefficients and their associated epochs.

          Example code begins here.

          /.
             Program spk14b_ex1
          ./
          #include "SpiceUsr.h"

          int main( )
          {

             /.
             Define the segment identifier parameters.
             ./
             #define SPK14        "spk14b_ex1.bsp"
             #define REF          "J2000"
             #define BODY         3
             #define CENTER       10
             #define CHBDEG       2
             #define NRECS        4
             #define RECSIZ     ( 2 + 6*(CHBDEG+1) )

             /.
             Local variables.
             ./
             SpiceChar          * ifname;
             SpiceChar          * segid;

             SpiceDouble          first;
             SpiceDouble          last;

             SpiceInt             handle;
             SpiceInt             ncomch;

             /.
             Define the epochs and coefficients.
             ./
             SpiceDouble          epochs [NRECS+1] = {
                            100.0, 200.0, 300.0, 400.0, 500.0 };

             SpiceDouble          recrds [NRECS][RECSIZ] = {
                                       {150.0, 50.0,
                                        1.0101, 1.0102, 1.0103,
                                        1.0201, 1.0202, 1.0203,
                                        1.0301, 1.0302, 1.0303,
                                        1.0401, 1.0402, 1.0403,
                                        1.0501, 1.0502, 1.0503,
                                        1.0601, 1.0602, 1.0603},
                                       {250.0, 50.0,
                                        2.0101, 2.0102, 2.0103,
                                        2.0201, 2.0202, 2.0203,
                                        2.0301, 2.0302, 2.0303,
                                        2.0401, 2.0402, 2.0403,
                                        2.0501, 2.0502, 2.0503,
                                        2.0601, 2.0602, 2.0603},
                                       {350.0, 50.0,
                                        3.0101, 3.0102, 3.0103,
                                        3.0201, 3.0202, 3.0203,
                                        3.0301, 3.0302, 3.0303,
                                        3.0401, 3.0402, 3.0403,
                                        3.0501, 3.0502, 3.0503,
                                        3.0601, 3.0602, 3.0603},
                                       {450.0, 50.0,
                                        4.0101, 4.0102, 4.0103,
                                        4.0201, 4.0202, 4.0203,
                                        4.0301, 4.0302, 4.0303,
                                        4.0401, 4.0402, 4.0403,
                                        4.0501, 4.0502, 4.0503,
                                        4.0601, 4.0602, 4.0603} };

             /.
             Set the start and end times of interval covered by
             segment.
             ./
             first = epochs[0];
             last  = epochs[NRECS];

             /.
             `ncomch' is the number of characters to reserve for the
             kernel's comment area. This example doesn't write
             comments, so set to zero.
             ./
             ncomch = 0;

             /.
             Internal file name and segment ID.
             ./
             ifname = "Type 14 SPK internal file name.";
             segid  = "SPK type 14 test segment";

             /.
             Open a new SPK file.
             ./
             spkopn_c ( SPK14, ifname, ncomch, &handle );

             /.
             Begin the segment.
             ./
             spk14b_c ( handle, segid, BODY, CENTER, REF, first, last, CHBDEG );

             /.
             Add the data to the segment all at once.
             ./
             spk14a_c ( handle, NRECS, recrds, epochs );

             /.
             End the segment, making the segment a permanent addition
             to the SPK file.
             ./
             spk14e_c ( handle );

             /.
             Close the SPK file.
             ./
             spkcls_c ( handle );

             return ( 0 );
          }

          When this program is executed, no output is presented on
          screen. After run completion, a new SPK type 14 exists in
          the output directory.

#### Restrictions

       1)  The SPK file must be open with write access.

       2)  Only one segment may be written to a particular SPK file at a
           time. All of the data for the segment must be written and the
           segment must be ended before another segment may be started in
           the file.

#### Literature_References

       None.

#### Author_and_Institution

       N.J. Bachman        (JPL)
       J. Diaz del Rio     (ODC Space)
       K.R. Gehringer      (JPL)
       B.V. Semenov        (JPL)

#### Version

       -CSPICE Version 1.0.2, 27-AUG-2021 (JDR)

           Edited the header to comply with NAIF standard. Added
           complete example code from existing fragment.

           Removed reference to other routines from -Abstract section
           (already in -Particulars).

       -CSPICE Version 1.0.1, 30-OCT-2006 (BVS)

           Deleted "inertial" from the "frame" description in the -Brief_I/O
           section of the header.

       -CSPICE Version 1.0.0, 29-JUL-1999 (NJB) (KRG)

#### Index_Entries

       begin writing a type_14 SPK segment

#### Link to routine spk14b_c source file spk14b_c.c

    Fri Dec 31 18:41:12 2021