spkw12_c |

## Procedurevoid 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 ) ## AbstractWrite a type 12 segment to an SPK file. ## Required_ReadingNAIF_IDS SPC SPK TIME ## KeywordsEPHEMERIS FILES ## Brief_I/OVariable 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_Inputhandle 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_OutputNone. See $Particulars for a description of the effect of this routine. ## ParametersThe 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 ## ExceptionsIf 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. ## FilesA new type 12 SPK segment is written to the SPK file attached to HANDLE. ## ParticularsThis 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. ## ExamplesSuppose 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. ./ ## RestrictionsNone. ## Literature_ReferencesNone. ## Author_and_InstitutionN.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_Entrieswrite spk type_12 ephemeris data segment |

Wed Apr 5 17:54:44 2017