Table of contents
CSPICE_DSKB02 returns bookkeeping data from a DSK type 2 segment.
Given:
handle the handle of a DSK file containing a type 2 segment from
which data are to be fetched.
[1,1] = size(handle); int32 = class(handle)
dladsc the DLA descriptor associated with the segment from which
data are to be fetched.
[SPICE_DLA_DSCSIZ,1] = size(dladsc)
int32 = class(dladsc)
the call:
[nv, np, nvxtot, ...
vtxbds, voxsiz, voxori, vgrext, ...
cgscal, vtxnpl, voxnpt, voxnpl] = cspice_dskb02( handle, dladsc )
returns:
nv the number of vertices belonging to the specified plate
model.
[1,1] = size(nv); int32 = class(nv)
np the number of plates belonging to the specified plate
model.
[1,1] = size(np); int32 = class(np)
nvxtot the total number of voxels in fine grid.
[1,1] = size(nvxtot); int32 = class(nvxtot)
vtxbds the vertex bounds.
[2,3] = size(vtxbds); double = class(vtxbds)
This is an array of six values giving the minimum and maximum
values of each component of the vertex set. Units are km.
voxsiz the fine grid voxel size.
[1,1] = size(voxsiz); double = class(voxsiz)
DSK voxels are cubes; the edge length of each cube is given by
the voxel size. This size applies to the fine voxel grid.
Units are km.
voxori the voxel grid origin.
[3,1] = size(voxori); double = class(voxori)
This is the location of the voxel grid origin in the
body-fixed frame associated with the target body.
Units are km.
vgrext the voxel grid extent.
[3,1] = size(vgrext); int32 = class(vgrext)
This extent is an array of three integers indicating the
number of voxels in the X, Y, and Z directions in the fine
voxel grid.
cgscal the coarse voxel grid scale.
[1,1] = size(cgscal); int32 = class(cgscal)
The extent of the fine voxel grid is related to the extent of
the coarse voxel grid by this scale factor.
vtxnpl the vertex-plate correspondence list size.
[1,1] = size(vtxnpl); int32 = class(vtxnpl)
voxnpt the size of the voxel-to-plate pointer list.
[1,1] = size(voxnpt); int32 = class(voxnpt)
voxnpl the voxel-plate correspondence list size.
[1,1] = size(voxnpl); int32 = class(voxnpl)
See the parameter definitions file
MiceDLA.m
for declarations of DLA descriptor sizes and documentation of the
contents of DLA descriptors.
See the parameter definitions file
MiceDSK.m
for declarations of DSK descriptor sizes and documentation of the
contents of DSK descriptors.
See the parameter definitions file
MiceDSK.m
for declarations of DSK data type 2 (plate model) parameters.
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) Dump several parameters from the first DLA segment of
a DSK file. The segment is assumed to be of type 2.
Example code begins here.
function dskb02_ex1( )
%
% Prompt for the name of the file to search.
%
fname = input( 'Name of DSK file > ', 's' );
%
% Open the DSK file for read access. We use the
% DAS-level interface for this function.
%
handle = cspice_dasopr( fname );
%
% Begin a forward search through the kernel. In
% this example, it's a very short search.
%
[ dladsc, found] = cspice_dlabfs( handle );
if ~found
txt = sprintf( ...
'SPICE(NOSEGMENT): No segment found in file %s.', ...
dsk);
error(txt)
end
%
% Loop over each segment.
%
while found
%
% If we made it this far, DLADSC is the
% DLA descriptor of the first segment.
% Read and display type 2 bookkeeping data.
%
[ nv, np, nvxtot, vtxbds, voxsiz, voxori, vgrext, ...
cgscal, vtxnpl, voxnpt, voxnpl] = cspice_dskb02( handle, dladsc);
fprintf( ['\n' ...
'Number of vertices: %ld\n' ...
'Number of plates: %ld\n' ...
'Number of voxels: %ld\n' ...
'Vertex bounds in X direction (km): %f : %f\n' ...
'Vertex bounds in Y direction (km): %f : %f\n' ...
'Vertex bounds in Z direction (km): %f : %f\n' ...
'Voxel edge length (km): %f\n' ...
'Voxel grid origin (km): ( %f %f %f )\n' ...
'Voxel grid extents: %ld %ld %ld\n' ...
'Coarse voxel grid scale: %ld\n' ...
'Size of vertex-plate list: %ld\n' ...
'Size of voxel-plate pointer array: %ld\n' ...
'Size of voxel-plate list: %ld\n'], ...
nv, ...
np, ...
nvxtot, ...
vtxbds(1,1), vtxbds(2,1), ...
vtxbds(1,2), vtxbds(2,2), ...
vtxbds(1,3), vtxbds(2,3), ...
voxsiz, ...
voxori(1), voxori(2), voxori(3), ...
vgrext(1), vgrext(2), vgrext(3), ...
cgscal, ...
vtxnpl, ...
voxnpt, ...
voxnpl )
%
% Search for the segment after that described by `dladsc'.
% `found' returns as false if no such segment located.
%
[nxtdsc, found] = cspice_dlafns( handle, dladsc);
dladsc = nxtdsc;
end
%
% Close the kernel. This frees program and system resources.
%
cspice_dascls( handle );
When this program was executed on a Mac/Intel/Octave5.x/64-bit
platform, using the DSK file named phobos512.bds, the output
was:
Name of DSK file > phobos512.bds
Number of vertices: 1579014
Number of plates: 3145728
Number of voxels: 11914500
Vertex bounds in X direction (km): -13.440030 : 12.762800
Vertex bounds in Y direction (km): -11.520650 : 12.061140
Vertex bounds in Z direction (km): -9.570780 : 10.055000
Voxel edge length (km): 0.104248
Voxel grid origin (km): ( -14.073520 -11.988554 -9.903588 )
Voxel grid extents: 260 235 195
Coarse voxel grid scale: 5
Size of vertex-plate list: 11010050
Size of voxel-plate pointer array: 1151500
Size of voxel-plate list: 6419540
This routine supports computations involving bookkeeping information
stored in DSK type 2 segments. User applications typically will not
need to call this routine.
DSK files are built using the DLA low-level format and the DAS
architecture; DLA files are a specialized type of DAS file in which
data are organized as a doubly linked list of segments. Each
segment's data belong to contiguous components of character, double
precision, and integer type.
1) If the input handle is invalid, an error is signaled by a
routine in the call tree of this routine.
2) If a file read error occurs, the error is signaled by a
routine in the call tree of this routine.
3) If the input DLA descriptor is invalid, the effect of this
routine is undefined. The error *may* be diagnosed by
routines in the call tree of this routine, but there are no
guarantees.
4) If any of the input arguments, `handle' or `dladsc', is
undefined, an error is signaled by the Matlab error handling
system.
5) If any of the input arguments, `handle' or `dladsc', is not of
the expected type, or it does not have the expected dimensions
and size, an error is signaled by the Mice interface.
See input argument `handle'.
1) The caller must verify that the segment associated with
the input DLA descriptor is a DSK type 2 segment.
DAS.REQ
DSK.REQ
MICE.REQ
None.
N.J. Bachman (JPL)
J. Diaz del Rio (ODC Space)
E.D. Wright (JPL)
-Mice Version 1.1.0, 07-AUG-2020 (EDW) (JDR)
Edited the header and the error message format to comply with
NAIF standard.
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, 27-APR-2016 (EDW) (NJB)
fetch parameters from a type 2 DSK segment
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