Index Page
spkw12_c
A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X 

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

   void spkw12_c ( SpiceInt             handle,
                   SpiceInt             body,
                   SpiceInt             center, 
                   ConstSpiceChar     * frame,
                   SpiceDouble          first,
                   SpiceDouble          last,
                   ConstSpiceChar     * segid,
                   SpiceInt             degree,
                   SpiceInt             n,
                   ConstSpiceDouble     states[][6],
                   SpiceDouble          epoch1,
                   SpiceDouble          step        )

Abstract

 
   Write a type 12 segment to an SPK file. 
 

Required_Reading

 
   NAIF_IDS 
   SPC 
   SPK 
   TIME 
 

Keywords

 
   EPHEMERIS 
   FILES 
 

Brief_I/O

 
   Variable  I/O  Description 
   --------  ---  -------------------------------------------------- 
   MAXDEG     P   Maximum degree of interpolating polynomials.
   TOLSCL     P   Scale factor used to compute time bound tolerance.
   handle     I   Handle of an SPK file open for writing. 
   body       I   NAIF code for an ephemeris object. 
   center     I   NAIF code for center of motion of body. 
   frame      I   Reference frame name. 
   first      I   Start time of interval covered by segment. 
   last       I   End time of interval covered by segment. 
   segid      I   Segment identifier. 
   degree     I   Degree of interpolating polynomials. 
   n          I   Number of states. 
   states     I   Array of states. 
   epoch1     I   Epoch of first state in states array.
   step       I   Time step separating epochs of states.
   MAXDEG     P   Maximum allowed degree of interpolating polynomial. 
 

Detailed_Input

 
   handle         is the file handle of an SPK file that has been 
                  opened for writing. 
 
   body           is the NAIF integer code for an ephemeris object 
                  whose state relative to another body is described 
                  by the segment to be created. 
 
   center         is the NAIF integer code for the center of motion 
                  of the object identified by body. 
 
   frame          is the NAIF name for a reference frame 
                  relative to which the state information for body 
                  is specified. 
 
   first, 
   last           are, respectively, the start and stop times of 
                  the time interval over which the segment defines 
                  the state of body. 
 
   segid          is the segment identifier.  An SPK segment 
                  identifier may contain up to 40 characters. 
 
   degree         is the degree of the Hermite polynomials used to 
                  interpolate the states.  All components of the 
                  state vectors are interpolated by polynomials of 
                  fixed degree. 
 
   n              is the number of states in the input state vector 
                  array. 
 
   states         contains a time-ordered array of geometric states 
                  ( x, y, z, dx/dt, dy/dt, dz/dt, in kilometers and 
                  kilometers per second ) of body relative to center, 
                  specified relative to frame. 
 
   epoch1         is the epoch corresponding to the first state in
                  the state array.  Because extra states are needed
                  at the beginning and end of the segment in order
                  for the interpolation method to work, epoch1 will
                  normally precede first.

   step           is the time step separating the epochs of adjacent
                  states in the input state array.  step is specified
                  in seconds.
 

Detailed_Output

 
   None.  See $Particulars for a description of the effect of this 
   routine. 
 

Parameters

 
   The parameters below are declared in the Fortran include file
   spk12.inc, which is part of the Fortran SPICE Toolkit (aka
   SPICELIB). The values of those parameters are used in CSPICE code
   generated by running f2c on SPICELIB source code. They are not
   directly referenced by code in this module.

      MAXDEG         is the maximum allowed degree of the interpolating 
                     polynomial. 
 
                     The value of MAXDEG is 27.


      TOLSCL         is a tolerance scale factor (also called a
                     "relative tolerance") used for time coverage bound
                     checking. TOLSCL is unitless. TOLSCL produces a
                     tolerance value via the formula
 
                        TOL = TOLSCL * max( abs(first), abs(last) )
 
                     where `first' and `last' are the coverage time
                     bounds of a type 12 segment, expressed as seconds
                     past J2000 TDB.
 
                     The resulting parameter TOL is used as a tolerance
                     for comparing the input segment descriptor time
                     bounds to the first and last epoch covered by the
                     sequence of time intervals defined by the inputs
                     to spkw12_c:
 
                        epoch1
                        step
                        n

                     The value of TOLSCL is 1.e-13.
 

Exceptions

 
   If any of the following exceptions occur, this routine will return 
   without creating a new segment. 
 
   1)  If frame is not a recognized name, the error 
       SPICE(INVALIDREFFRAME) is signaled. 
 
   2)  If the last non-blank character of segid occurs past index 40, 
       the error SPICE(SEGIDTOOLONG) is signaled. 
 
   3)  If segid contains any nonprintable characters, the error 
       SPICE(NONPRINTABLECHARS) is signaled. 
 
   4)  If degree is not at least 1 or is greater than MAXDEG, the 
       error SPICE(INVALIDDEGREE) is signaled. 
 
   5)  If degree is not odd, the error SPICE(INVALIDDEGREE) is  
       signaled. 
 
   6)  If the number of states n is not at least (degree+1)/2,  
       the error SPICE(TOOFEWSTATES) will be signaled. 
 
   7)  If first is greater than or equal to last then the error 
       SPICE(BADDESCRTIMES) will be signaled. 
 
   8)  If step is non-positive, the error SPICE(INVALIDSTEPSIZE) will
       be signaled.

   9)  If the start time of the first record exceeds the descriptor
       begin time by more than a computed tolerance, or if the end time
       of the last record precedes the descriptor end time by more than
       a computed tolerance, the error SPICE(COVERAGEGAP) is signaled.
       See the Parameters section above for a description of the
       tolerance.
 
   10) If either the input frame or segment ID string pointer is null,
       the error SPICE(NULLPOINTER) is signaled.
   
   11) If either the input frame or segment ID string is empty,
       the error SPICE(EMPTYSTRING) is signaled.
   
 

Files

 
   A new type 12 SPK segment is written to the SPK file attached 
   to HANDLE. 
 

Particulars

 
   This routine writes an SPK type 12 data segment to the open SPK 
   file according to the format described in the type 12 section of 
   the SPK Required Reading. The SPK file must have been opened with 
   write access. 
 

Examples

 
   Suppose that you have states and are prepared to produce 
   a segment of type 12 in an SPK file. 
 
   The following code fragment could be used to add the new segment 
   to a previously opened SPK file attached to handle. The file must 
   have been opened with write access. 
 
      #include "SpiceUsr.h"
           .
           .
           .
        
      /.
      Create a segment identifier. 
      ./
      #define  SEGID  "MY_SAMPLE_SPK_TYPE_12_SEGMENT" 
 
        
      /.
      Write the segment. 
      ./
        
      spkw12_c ( handle,  body,    center,  frame, 
                 first,   last,    segid,   degree, 
                 n,       states,  epoch1,  step   );
 

Restrictions

 
   None. 
 

Literature_References

 
   None. 
 

Author_and_Institution

 
   N.J. Bachman   (JPL) 
 

Version

 
   -CSPICE Version 2.0.0, 11-JAN-2014 (NJB) 

       Relaxed test on relationship between the time bounds of the
       input record set (determined by `epoch1', `step', and `n') and
       the descriptor bounds `first' and `last'. Now the descriptor
       bounds may extend beyond the time bounds of the record set by a
       ratio computed using the parameter TOLSCL (see Parameters above
       for details). Added checks on input polynomial degree.
       Renamed argument `epoch0' to `epoch1' for consistency with other
       CSPICE and SPICELIB interfaces.

   -CSPICE Version 1.0.0, 23-FEB-2000 (NJB)

Index_Entries

 
   write spk type_12 ephemeris data segment 
 
Wed Apr  5 17:54:44 2017