Open an existing SPK file for subsequent write.
VARIABLE I/O DESCRIPTION -------- --- -------------------------------------------------- file I The name of an existing SPK file. handle O A handle attached to the SPK file opened to append.
file is the name of an existing SPK file to which you wish to append additional SPK segments.
handle is the DAF integer handle that refers to the SPK file opened for appending.
This file provides an interface for opening existing SPK files for the addition of SPK segments. If you need to open an new SPK file for writing, call the routine SPKOPN.
Suppose you have collected data for a type 05 SPK segment and wish to place the new segment in an existing SPK file. The code fragment below shows one set of calls that you could perform to make the addition. (Note that you could add segments of other data types by replacing the call to spkw05_c with a suitably modified call to another spkwXX_c routine.) We assume that the following variables have already been assigned the proper values: body (integer) Body code for ephemeris object. center (integer) body code for the center of motion of the body. frame (string) the reference frame of the states. first (d.p.) first valid time for which states can be computed in seconds past 2000. last (d.p.) last valid time for which states can be computed in seconds past 2000. gm (d.p.) gravitational mass of central body. n (integer) number of states and epochs. states (d.p.) array of states (x,y,z,dx,dy,dz). epochs (d.p.) array of epochs (seconds past 2000.) segid (string) segment identifier #include "SpiceUsr.h" . . . /. Begin by opening the file. ./ spkopa_c ( file, &handle ); /. Now add the collected data as a new segment. ./ spkw05_c ( handle, body, center, frame, first, last, segid, gm, n, states, epochs ); /. Finally, close the file. ./ spkcls_c ( handle );
1) If the file specified does not exist the error SPICE(FILENOTFOUND) will be signalled. 2) If the file specified is not an SPK file, the error SPICE(FILEISNOTSPK) will be signalled. 3) If the string pointer file is null, the error SPICE(NULLPOINTER) will be signaled. 4) If the string file has length zero, the error SPICE(EMPTYSTRING) will be signaled. All other exceptions are determined by routines in the call tree of this routine. If any exceptions arise that prevent opening of the specified file for writing, HANDLE will be returned with the value 0.
See arguments file and handle.
F.S. Turner (JPL)
-CSPICE Version 1.0.0, 16-MAR-1999 (FST)
Open an existing SPK file for adding segments