pckopn_c |
Table of contents
Procedurepckopn_c ( PCK, open new file ) void pckopn_c ( ConstSpiceChar * name, ConstSpiceChar * ifname, SpiceInt ncomch, SpiceInt * handle ) AbstractCreate a new PCK file, returning the handle of the opened file. Required_ReadingPCK KeywordsPCK Brief_I/OVARIABLE I/O DESCRIPTION -------- --- -------------------------------------------------- name I The name of the PCK file to be opened. ifname I The internal filename for the PCK. ncomch I The number of characters to reserve for comments. handle O The handle of the opened PCK file. Detailed_Inputname is the name of the PCK file to be created. ifname is the internal filename for the PCK file that is being created. The internal filename may be up to 60 characters long. `ifname' may not contain non-printing characters; otherwise there are no restrictions on its contents. ncomch is the space, measured in characters, to be initially set aside for the comment area when a new PCK file is opened. The amount of space actually set aside may be greater than the amount requested, due to the manner in which comment records are allocated in an PCK file. However, the amount of space set aside for comments will always be at least the amount that was requested. The value of ncomch should be greater than or equal to zero, i.e., 0 <= ncomch. A negative value, should one occur, will be assumed to be zero. Detailed_Outputhandle is the handle of the opened PCK file. If an error occurs when opening the file, the value of this variable should not be used, as it will not represent a valid handle. ParametersNone. Exceptions1) If the value of `ncomch' is negative, a value of zero (0) will be used for the number of comment characters to be set aside for comments. 2) If an error occurs while attempting to open a CK file the value of `handle' will not represent a valid file handle. 3) If any of the `name' or `ifname' input string pointers is null, the error SPICE(NULLPOINTER) is signaled. 4) If any of the `name' or `ifname' input strings has zero length, the error SPICE(EMPTYSTRING) is signaled. FilesSee descriptions of `name' and `handle'. ParticularsOpen a new PCK file, reserving room for comments if requested. ExamplesThe 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) Suppose that you have sets of Chebyshev polynomial coefficients in an array pertaining to the orientation of the Moon body-fixed frame with the frame class ID 301 relative to the J2000 reference frame, and want to put these into a type 2 segment PCK file. The following example could be used to add one new type 2 segment. To add multiple segments, put the call to pckw02_c in a loop. Example code begins here. /. Program pckopn_ex1 ./ #include "SpiceUsr.h" int main( ) { /. Local parameters ./ #define FNAME "pckopn_ex1.bpc" #define BODY 301 #define POLYDG 9 #define SZCDAT 60 /. Local variables ./ SpiceChar * ifname; SpiceChar * segid; SpiceDouble btime; SpiceDouble first; SpiceDouble intlen; SpiceDouble last; SpiceInt handle; SpiceInt n; SpiceInt nresvc; /. Set the input data: RA/DEC/W coefficients, begin time for the first record, start/end times for the segment, length of the time covered by each record, and number of logical records. `cdata' contains the ra/dec/w coefficients: first the the polydeg + 1 for the RA first record, then the polydeg + 1 for the DEC first record, then the polydeg +1 for W first record, then the polydeg + 1 for the RA second record, and so on. ./ SpiceDouble cdata [SZCDAT] = { -5.4242086033301107e-002, -5.2241405162792561e-005, 8.9751456289930307e-005, -1.5288696963234620e-005, 1.3218870864581395e-006, 5.9822156790328180e-007, -6.5967702052551211e-008, -9.9084309118396298e-009, 4.9276055963541578e-010, 1.1612267413829385e-010, 0.42498898565916610, 1.3999219324235620e-004, -1.8855140511098865e-005, -2.1964684808526649e-006, 1.4229817868138752e-006, -1.6991716166847001e-007, -3.4824688140649506e-008, 2.9208428745895990e-009, 4.4217757657060300e-010, -3.9211207055305402e-012, 2565.0633504619473, 0.92003769451305328, -8.0503797901914501e-005, 1.1960860244433900e-005, -1.2237900518372542e-006, -5.3651349407824562e-007, 6.0843372260403005e-008, 9.0211287487688797e-009, -4.6460429330339309e-010, -1.0446918704281774e-010, -5.3839796353225056e-002, 4.3378021974424991e-004, 4.8130091384819459e-005, -1.2283066272873327e-005, -5.4099296265403208e-006, -4.4237368347319652e-007, 1.3004982445546169e-007, 1.9017128275284284e-008, -7.0368223839477803e-011, -1.7119414526133175e-010, 0.42507987850614548, -7.1844899448557937e-005, -5.1052122872412865e-005, -8.9810401387721321e-006, -1.4611718567948972e-007, 4.0883847771062547e-007, 4.6812854485029333e-008, -4.5698075960784951e-009, -9.8679875320349531e-010, -7.9392503778178240e-011, 2566.9029069934054, 0.91952244801740568, -6.0426151041179828e-005, 1.0850559330577959e-005, 5.1756033678137497e-006, 4.2127585555214782e-007, -1.1774737441872970e-007, -1.7397191490163833e-008, 5.8908810244396165e-012, 1.4594279337955166e-010 }; first = -43200.0; last = 1339200.0; btime = first; intlen = 691200.0; n = 2; /. Open a new PCK file. For simplicity, we will not reserve any space for the comment area, so the number of reserved comment characters is zero. The variable `ifname' is the internal file name. ./ nresvc = 0; ifname = "Test PCK/Created 04-SEP-2019"; pckopn_c ( FNAME, ifname, nresvc, &handle ); /. Create a segment identifier. ./ segid = "MY_SAMPLE_PCK_TYPE_2_SEGMENT"; /. Write the segment. ./ pckw02_c ( handle, BODY, "J2000", first, last, segid, intlen, n, POLYDG, cdata, btime ); /. Close the file. ./ pckcls_c ( handle ); return ( 0 ); } When this program is executed, no output is presented on screen. After run completion, a new PCK type 2 exists in the output directory. RestrictionsNone. Literature_ReferencesNone. Author_and_InstitutionN.J. Bachman (JPL) J. Diaz del Rio (ODC Space) K.R. Gehringer (JPL) Version-CSPICE Version 1.0.1, 04-AUG-2021 (JDR) Edited the header to comply with NAIF standard. Added complete code examples based on existing fragment. -CSPICE Version 1.0.0, 16-DEC-2016 (NJB) (KRG) Index_Entriesopen a new PCK file |
Fri Dec 31 18:41:10 2021