| dasopr_c |
|
Table of contents
Procedure
dasopr_c ( DAS, open for read )
void dasopr_c ( ConstSpiceChar * fname,
SpiceInt * handle )
AbstractOpen a DAS file for reading. Required_ReadingDAS KeywordsDAS FILES Brief_I/OVARIABLE I/O DESCRIPTION -------- --- -------------------------------------------------- fname I Name of a DAS file to be opened. handle O Handle assigned to the opened DAS file. Detailed_Input
fname is the name of a DAS file to be opened with read
access.
Detailed_Output
handle is the handle that is associated with the file. This
handle is used to identify the file in subsequent
calls to other DAS routines.
ParametersNone. Exceptions
1) If the input filename is blank, the error SPICE(BLANKFILENAME)
is signaled by a routine in the call tree of this routine.
2) If the specified file does not exist, the error
SPICE(FILENOTFOUND) is signaled by a routine in the call tree
of this routine.
3) If the specified file has already been opened for read
access, the handle already associated with the file is
returned.
4) If the specified file has already been opened for write
access, the error SPICE(DASRWCONFLICT) is signaled by a
routine in the call tree of this routine.
5) If the specified file has already been opened by a non-DAS
routine, the error SPICE(DASIMPROPOPEN) is signaled by a
routine in the call tree of this routine.
6) If the specified file cannot be opened without exceeding the
maximum allowed number of open DAS files, the error
SPICE(DASFTFULL) is signaled by a routine in the call tree of
this routine.
7) If the named file cannot be opened properly, an error is
signaled by a routine in the call tree of this routine.
8) If the file record cannot be read, the error
SPICE(FILEREADFAILED) is signaled by a routine in the call
tree of this routine.
9) If the specified file is not a DAS file, as indicated by the
file's ID word, an error is signaled by a routine in the call
tree of this routine.
10) If no logical units are available, an error is signaled
by a routine in the call tree of this routine.
11) If the `fname' input string pointer is null, the error
SPICE(NULLPOINTER) is signaled.
12) If the `fname' input string has zero length, the error
SPICE(EMPTYSTRING) is signaled.
FilesSee argument `fname'. ParticularsMost DAS files require only read access. If you do not need to change the contents of a file, you should open it using dasopr_c. Examples
The 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) Dump several parameters from the first DLA segment of a DSK
file. Note that DSK files are based on DAS. The segment is
assumed to be of type 2.
Example code begins here.
/.
Program dasopr_ex1
./
#include <stdio.h>
#include "SpiceUsr.h"
int main()
{
/.
Constants
./
#define FILSIZ 256
/.
Local variables
./
SpiceBoolean found;
SpiceChar dsk [ FILSIZ ];
SpiceDLADescr dladsc;
SpiceDouble voxori [3];
SpiceDouble voxsiz;
SpiceDouble vtxbds [3][2];
SpiceInt cgscal;
SpiceInt handle;
SpiceInt np;
SpiceInt nv;
SpiceInt nvxtot;
SpiceInt vgrext [3];
SpiceInt voxnpl;
SpiceInt voxnpt;
SpiceInt vtxnpl;
/.
Prompt for the name of DSK to read.
./
prompt_c ( "Enter DSK name > ", FILSIZ, dsk );
/.
Open the DSK file for read access. We use the
DAS-level interface for this function.
./
dasopr_c ( dsk, &handle );
/.
Begin a forward search through the kernel. In
this example, it's a very short search.
./
dlabfs_c ( handle, &dladsc, &found );
if ( !found )
{
setmsg_c ( "No segment found in file #." );
errch_c ( "#", dsk );
sigerr_c ( "SPICE(NOSEGMENT)" );
}
/.
If we made it this far, DLADSC is the
DLA descriptor of the first segment.
Read and display type 2 bookkeeping data.
./
dskb02_c ( handle, &dladsc, &nv, &np, &nvxtot,
vtxbds, &voxsiz, voxori, vgrext, &cgscal,
&vtxnpl, &voxnpt, &voxnpl );
printf ( "\n"
"Number of vertices: %d\n"
"Number of plates: %d\n"
"Number of voxels: %d\n",
(int)nv,
(int)np,
(int)nvxtot );
printf ( "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",
vtxbds[0][0], vtxbds[0][1],
vtxbds[1][0], vtxbds[1][1],
vtxbds[2][0], vtxbds[2][1] );
printf ( "Voxel edge length (km): %f\n"
"Voxel grid origin (km): ( %f %f %f )\n"
"Voxel grid extents: %d %d %d\n"
"Coarse voxel grid scale: %d\n"
"Size of vertex-plate list: %d\n"
"Size of voxel-plate pointer array: %d\n"
"Size of voxel-plate list: %d\n",
voxsiz,
voxori[0], voxori[1], voxori[2],
(int)vgrext[0], (int)vgrext[1], (int)vgrext[2],
(int)cgscal,
(int)vtxnpl,
(int)voxnpt,
(int)voxnpl );
/.
Close the kernel. This isn't necessary in a stand-
alone program, but it's good practice in subroutines
because it frees program and system resources.
./
dascls_c ( handle );
return ( 0 );
}
When this program was executed on a Mac/Intel/cc/64-bit
platform, using the DSK file named phobos512.bds,
the output was:
Enter DSK name > 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
RestrictionsNone. Literature_ReferencesNone. Author_and_InstitutionN.J. Bachman (JPL) J. Diaz del Rio (ODC Space) K.R. Gehringer (JPL) W.L. Taber (JPL) F.S. Turner (JPL) I.M. Underwood (JPL) Version
-CSPICE Version 1.0.1, 10-AUG-2021 (JDR)
Improved the -Exceptions section.
Edited the header to comply with NAIF standard. Added
complete code example using example from dskb02_c.
-CSPICE Version 1.0.0, 05-OCT-2006 (NJB) (KRG) (WLT) (FST) (IMU)
Index_Entriesopen a DAS file for reading open a DAS file for read access |
Fri Dec 31 18:41:04 2021