Table of contents
CSPICE_DAFUS unpacks an array summary into its double precision and
integer components.
Given:
sum an containing the DAF array summary. This identifies the
contents and location of a single array within a DAF.
[n,1] = size(sum); double = class(sum)
nd the size of the return double precision array.
[1,1] = size(nd); int32 = class(nd)
ni the size of the return integer array.
[1,1] = size(ni); int32 = class(ni)
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:
[dc, ic] = cspice_dafus( sum, nd, ni )
returns:
dc the array of double precision components of the summary.
[1,nd] = size(dc); double = class(dc)
ic the array of integer components of the summary.
[1,ni] = size(ic); int32 = class(ic)
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) Find a segment for the Pluto barycenter, with coverage for
a specified epoch, in a JPL planetary SPK file, and display
the segment's information.
Use the meta-kernel shown below to load the required SPICE
kernels.
KPL/MK
File name: dafus_ex1.tm
This meta-kernel is intended to support operation of SPICE
example programs. The kernels shown here should not be
assumed to contain adequate or correct versions of data
required by SPICE-based user applications.
In order for an application to use this meta-kernel, the
kernels referenced here must be present in the user's
current working directory.
The names and contents of the kernels referenced
by this meta-kernel are as follows:
File name Contents
--------- --------
de421.bsp Planetary ephemeris
naif0010.tls Leapseconds
\begindata
KERNELS_TO_LOAD = ( 'de421.bsp',
'naif0010.tls' )
\begintext
End of meta-kernel
Example code begins here.
function dafus_ex1()
%
% Local constants
%
META = 'dafus_ex1.tm';
ND = 2;
NI = 6;
%
% Load a meta-kernel that specifies a planetary SPK file
% and leapseconds kernel. The contents of this meta-kernel
% are displayed above.
%
cspice_furnsh( META )
%
% Get the NAIF ID code for the Pluto system barycenter.
% This is a built-in ID code, so something's seriously
% wrong if we can't find the code.
%
[idcode, found] = cspice_bodn2c( 'PLUTO BARYCENTER' );
if ~found
cspice_kclear
error( 'SPICE(BUG)' )
end
%
% Pick a request time; convert to seconds past J2000 TDB.
%
reqtim = '2011 FEB 18 UTC';
et = cspice_str2et( reqtim );
%
% Find a loaded segment for the specified body and time.
%
[handle, descr, segid, found] = cspice_spksfs( idcode, et );
if ~found
cspice_kclear
txt = sprintf( ['No descriptor found for the ', ...
'body %d at time %s'], idcode, et );
error( txt )
else
%
% Display the DAF file handle.
%
fprintf( 'DAF handle: %d\n', handle )
%
% Display the segment ID.
%
%
% Unpack the descriptor. Display the contents.
%
[dc, ic] = cspice_dafus( descr, ND, NI );
fprintf( 'Segment ID: %s\n', segid )
fprintf( 'Body ID code: %d\n', ic(1) )
fprintf( 'Center ID code: %d\n', ic(2) )
fprintf( 'Frame ID code: %d\n', ic(3) )
fprintf( 'SPK data type: %d\n', ic(4) )
fprintf( 'Start time (TDB): %f\n', dc(1) )
fprintf( 'Stop time (TDB): %f\n', dc(2) )
end
%
% It's always good form to unload kernels after use,
% particularly in Matlab due to data persistence.
%
cspice_kclear
When this program was executed on a Mac/Intel/Octave6.x/64-bit
platform, the output was:
DAF handle: 1
Segment ID: DE-0421LE-0421
Body ID code: 9
Center ID code: 0
Frame ID code: 1
SPK data type: 2
Start time (TDB): -3169195200.000000
Stop time (TDB): 1696852800.000000
The components of array summaries are packed into double
precision arrays.
The total size of the summary is
(ni - 1)
nd + -------- + 1
2
double precision words (where `nd', `ni' are nonnegative).
1) If `nd' is zero or negative, no double precision components
are returned.
2) If `ni' is zero or negative, no integer components are returned.
3) If the total size of the summary is greater than 125 double
precision words, some components may not be returned.
4) If any of the input arguments, `sum', `nd' or `ni', is
undefined, an error is signaled by the Matlab error handling
system.
5) If any of the input arguments, `sum', `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 Mice interface.
None.
None.
MICE.REQ
DAF.REQ
None.
J. Diaz del Rio (ODC Space)
E.D. Wright (JPL)
-Mice Version 1.1.0, 10-AUG-2021 (EDW) (JDR)
Corrected size information of input argument "sum".
Edited the -Examples section to comply with NAIF standard. Added
example's problem statement and meta-kernel.
Added -Parameters, -Exceptions, -Files, -Restrictions,
-Literature_References and -Author_and_Institution sections.
Eliminated use of "lasterror" in rethrow.
Removed reference to the function's corresponding CSPICE header from
-Required_Reading section.
-Mice Version 1.0.0, 29-OCT-2012 (EDW)
get DAF summary
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