Table of contents
CSPICE_DAFGS returns the summary of the current DAF array,
i.e. the array found by the previous call to cspice_daffna
or cspice_daffpa.
Given:
nd a scalar integer defining the size of the return double
precision array.
help, nd
LONG = Scalar
ni a scalar integer defining the size of the return integer array.
help, ni
LONG = Scalar
For an SPK file, `nd' always equals 2, `ni' always equals 6.
The precise contents of the vectors depend on the type of DAF
but the final two elements of the `ic' (integer) vector always
contains the initial and final addresses respectively of the
array.
the call:
cspice_dafgs, nd, ni, dc, ic
returns:
dc the array of double precision components of the summary.
help, dc
DOUBLE = Array[nd]
ic the array of integer components of the summary.
help, ic
LONG = Array[ni]
None.
Any numerical results shown for this example may differ between
platforms as the results depend on the SPICE kernels used as input
and the machine specific arithmetic implementation.
1) Create a simple program to output the double precision and integer
values stored in an SPK's segments' descriptors. This program opens
a DAF for read, performs a forward search for the DAF arrays,
prints the segment descriptor for each array found, then closes
the DAF.
Use the SPK kernel below as input DAF file for the program.
de421.bsp
Example code begins here.
PRO dafgs_ex1
;;
;; Local constants
;;
kernel = 'de421.bsp'
;;
;; Open a DAF file for read. Return a `handle' referring
;; to the file.
;;
cspice_dafopr, kernel, handle
;;
;; Define the summary parameters appropriate
;; for an SPK file.
;;
ND = 2L
NI = 6L
;;
;; Begin a forward search on the file.
;;
cspice_dafbfs, handle
;;
;; Search until a DAF array is found.
;;
cspice_daffna, found
;;
;; Loop while the search finds subsequent DAF arrays.
;;
while found do begin
cspice_dafgs, ND, NI, dc, ic
print, 'Doubles: ', dc
print, FORMAT='(A,6I8)', 'Integers: ', ic
print, ' '
;;
;; Check for another segment.
;;
cspice_daffna, found
endwhile
;;
;; Safely close the DAF file.
;;
cspice_dafcls, handle
END
When this program was executed on a Mac/Intel/IDL8.x/64-bit
platform, the output was:
Doubles: -3.1691952e+09 1.6968528e+09
Integers: 1 0 1 2 641 310404
Doubles: -3.1691952e+09 1.6968528e+09
Integers: 2 0 1 2 310405 423048
Doubles: -3.1691952e+09 1.6968528e+09
Integers: 3 0 1 2 423049 567372
Doubles: -3.1691952e+09 1.6968528e+09
Integers: 4 0 1 2 567373 628976
Doubles: -3.1691952e+09 1.6968528e+09
Integers: 5 0 1 2 628977 674740
Doubles: -3.1691952e+09 1.6968528e+09
Integers: 6 0 1 2 674741 715224
Doubles: -3.1691952e+09 1.6968528e+09
Integers: 7 0 1 2 715225 750428
Doubles: -3.1691952e+09 1.6968528e+09
Integers: 8 0 1 2 750429 785632
Doubles: -3.1691952e+09 1.6968528e+09
Integers: 9 0 1 2 785633 820836
Doubles: -3.1691952e+09 1.6968528e+09
Integers: 10 0 1 2 820837 944040
Doubles: -3.1691952e+09 1.6968528e+09
Integers: 301 3 1 2 944041 1521324
Doubles: -3.1691952e+09 1.6968528e+09
Integers: 399 3 1 2 1521325 2098608
Doubles: -3.1691952e+09 1.6968528e+09
Integers: 199 1 1 2 2098609 2098620
Doubles: -3.1691952e+09 1.6968528e+09
Integers: 299 2 1 2 2098621 2098632
Doubles: -3.1691952e+09 1.6968528e+09
Integers: 499 4 1 2 2098633 2098644
Note, the specific contents of `ic' and `dc' depend on the
type of DAF.
Note, the final entries in the integer array contain the segment
start/end indexes. The output indicates the search proceeded
from the start of the file (low value index) towards the end
(high value index).
A single call to cspice_dafgs equates to the C calls:
dafgs_c( sum );
dafus_c( sum, nd, ni, dc, ic );
without use of the `sum' variable.
1) If this routine is called when no search is in progress in the
the current DAF, the error SPICE(DAFNOSEARCH) is signaled by a
routine in the call tree of this routine.
2) If the DAF for which the "current" array's summary is to be
returned has actually been closed, an error is signaled by a
routine in the call tree of this routine.
3) If no array is current in the current DAF, the error
SPICE(NOCURRENTARRAY) is signaled by a routine in the call tree
of this routine. There is no current array when a search is
started by cspice_dafbfs or cspice_dafbbs, but no calls to
cspice_daffna or cspice_daffpa have been made yet, or whenever
cspice_daffna or cspice_daffpa return the value False.
4) If `nd' is zero or negative, no double precision components
are returned.
5) If `ni' is zero or negative, no integer components are returned.
6) If any of the input arguments, `nd' or `ni', is undefined, an
error is signaled by the IDL error handling system.
7) If any of the input arguments, `nd' or `ni', is not of the
expected type, or it does not have the expected dimensions and
size, an error is signaled by the Icy interface.
8) If any of the output arguments, `dc' or `ic', is not a named
variable, an error is signaled by the Icy interface.
None.
None.
ICY.REQ
DAF.REQ
None.
J. Diaz del Rio (ODC Space)
E.D. Wright (JPL)
-Icy Version 1.0.2, 09-JUL-2021 (JDR)
Edited the header to comply with NAIF standard.
Modified code example to hardcode the input DAF file.
Added -Parameters, -Exceptions, -Files, -Restrictions,
-Literature_References and -Author_and_Institution sections.
Removed reference to the routine's corresponding CSPICE header from
-Abstract section.
Added arguments' type and size information in the -I/O section.
-Icy Version 1.0.1, 11-NOV-2013 (EDW)
Edits and clean up to header text.
-Icy Version 1.0.0, 16-JUN-2003 (EDW)
get DAF summary
|