| dskcls_c |
|
Table of contents
Procedure
dskcls_c ( DSK, close file )
void dskcls_c ( SpiceInt handle,
SpiceBoolean optmiz )
AbstractClose a DSK file. Required_ReadingDAS DSK KeywordsDAS DSK FILES TOPOGRAPHY Brief_I/OVARIABLE I/O DESCRIPTION -------- --- -------------------------------------------------- handle I Handle assigned to the opened DSK file. optmiz I Flag indicating whether to segregate the DSK. Detailed_Input
handle is the DAS file handle associated with the file.
The file may be open for read or write access.
optmiz is a logical flag indicating whether the DSK
should be segregated before it is closed. This
option applies only to files open for write
access. The value of `optmiz' has no effect for
files opened for read access.
See the DAS Required Reading das.req for a
discussion of segregation of DAS files.
Detailed_OutputNone. This routine operates by side effects. ParametersNone. Exceptions
1) If an error occurs when the file is closed, the error is
signaled by a routine in the call tree of this routine.
FilesSee argument `handle'. ParticularsThis routine provides a DSK-level interface for closing DSK files. In cases where DSKs opened for write access are to be closed without segregation, this interface is slightly simpler than that available at the DAS level. Examples
The numerical results shown for these examples 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) Create a three-segment DSK file using plate model data for
Phobos. Use latitudinal, rectangular, and planetodetic
coordinates in the respective segments. This is not a
realistic example, but it serves to demonstrate use of
the supported coordinate systems.
Use the DSK kernel below to provide, for simplicity, the
input plate and vertex data. The selected input file has one
segment.
phobos_3_3.bds
Example code begins here.
/.
Program dskcls_ex1
Example program for dskw02_c, dskmi2_c, and dskrb2_c
Create a three-segment DSK file using plate model data for
Phobos. Use latitudinal, rectangular, and planetodetic
coordinates in the respective segments.
For simplicity, use an existing DSK file to provide the
input plate and vertex data. The selected input file has one
segment.
Version 1.0.0 22-JAN-2016 (NJB)
./
#include <stdio.h>
#include "SpiceUsr.h"
int main()
{
/.
Local constants
./
#define FILSIZ 256
#define LNSIZE 81
#define NCOR 4
#define NSEG 3
#define NAMLEN 21
/.
Local variables
./
/.
Below, we declare large arrays static to avoid stack
overflow problems.
./
SpiceBoolean found;
SpiceChar cornam [ NCOR ][ NAMLEN ] =
{ "radius",
"Z-coordinate",
"Z-coordinate",
"altitude" };
SpiceChar * dsk;
SpiceChar * frame;
SpiceChar * indsk;
SpiceDLADescr dladsc;
SpiceDouble corpar [ SPICE_DSK_NSYPAR ];
SpiceDouble f;
SpiceDouble finscl;
SpiceDouble first;
SpiceDouble last;
SpiceDouble mncor1;
SpiceDouble mncor2;
SpiceDouble mncor3;
SpiceDouble mxcor1;
SpiceDouble mxcor2;
SpiceDouble mxcor3;
SpiceDouble re;
SpiceDouble rp;
/.
Note: the values of SPICE_DSK02_MAXVRT and
SPICE_DSK02_MAXPLT declared in SpiceDSK.h,
integer spatial index dimension SPICE_DSK02_SPAISZ,
and the workspace dimension SPICE_DSK02_MAXCEL
are very large. Smaller buffers can be used for most
applications.
./
static SpiceDouble spaixd [ SPICE_DSK02_SPADSZ ];
static SpiceDouble vrtces [ SPICE_DSK02_MAXVRT ][3];
SpiceInt center;
SpiceInt corscl;
SpiceInt corsys;
SpiceInt dclass;
SpiceInt handle;
SpiceInt i;
SpiceInt inhan;
SpiceInt np;
SpiceInt nv;
static SpiceInt plates [ SPICE_DSK02_MAXPLT ][3];
SpiceInt segno;
static SpiceInt spaixi [ SPICE_DSK02_SPAISZ ];
SpiceInt spaisz;
SpiceInt surfid;
SpiceInt voxpsz;
SpiceInt voxlsz;
static SpiceInt work [ SPICE_DSK02_MAXCEL ][2];
SpiceInt worksz;
/.
Assign names of input and output DSK files.
./
indsk = "phobos_3_3.bds";
dsk = "phobos_3_3_3seg.bds";
/.
Open input DSK for read access; find first segment.
./
dasopr_c ( indsk, &inhan );
dlabfs_c ( inhan, &dladsc, &found );
/.
Fetch vertices and plates from input DSK file.
Note that vertex and plate indices are 1-based.
./
printf ( "Reading input data...\n" );
dskv02_c ( inhan, &dladsc, 1, SPICE_DSK02_MAXVRT,
&nv, vrtces );
dskp02_c ( inhan, &dladsc, 1, SPICE_DSK02_MAXPLT,
&np, plates );
printf ( "Done.\n" );
/.
Set input array sizes required by dskmi2_c.
./
voxpsz = SPICE_DSK02_MAXVXP;
voxlsz = SPICE_DSK02_MXNVLS;
worksz = SPICE_DSK02_MAXCEL;
spaisz = SPICE_DSK02_SPAISZ;
/.
Set fine and coarse voxel scales. (These usually
need to determined by experimentation.)
./
finscl = 5.0;
corscl = 4;
/.
Open a new DSK file.
./
dskopn_c ( dsk, dsk, 0, &handle );
/.
Create three segments and add them to the file.
./
for ( segno = 1; segno <= NSEG; segno++ )
{
/.
Create spatial index. We won't generate a
vertex-plate mapping, so we set the flag
for creating this map to "false."
./
printf ( "Creating segment %d\n", (int)segno );
printf ( "Creating spatial index...\n" );
dskmi2_c ( nv, vrtces, np, plates,
finscl, corscl, worksz, voxpsz,
voxlsz, SPICEFALSE, spaisz, work,
spaixd, spaixi );
printf ( "Done.\n" );
/.
Set up inputs describing segment attributes:
- Central body: Phobos
- Surface ID code: user's choice.
We use the segment number here.
- Data class: general (arbitrary) shape
- Body-fixed reference frame
- Time coverage bounds (TBD)
./
center = 401;
surfid = segno;
dclass = SPICE_DSK_GENCLS;
frame = "IAU_PHOBOS";
first = -50 * jyear_c();
last = 50 * jyear_c();
/.
Set the coordinate system and coordinate system
bounds based on the segment index.
Zero out the coordinate parameters to start.
./
for ( i = 0; i < SPICE_DSK_NSYPAR; i++ )
{
corpar[i] = 0.0;
}
if ( segno == 1 )
{
/.
Use planetocentric latitudinal coordinates. Set
the longitude and latitude bounds.
./
corsys = SPICE_DSK_LATSYS;
mncor1 = -pi_c();
mxcor1 = pi_c();
mncor2 = -pi_c()/2;
mxcor2 = pi_c()/2;
}
else if ( segno == 2 )
{
/.
Use rectangular coordinates. Set the
X and Y bounds.
The bounds shown here were derived from
the plate data. They lie slightly outside
of the range spanned by the plates.
./
corsys = SPICE_DSK_RECSYS;
mncor1 = -1.3;
mxcor1 = 1.31;
mncor2 = -1.21;
mxcor2 = 1.2;
}
else
{
/.
Set the coordinate system to planetodetic.
./
corsys = SPICE_DSK_PDTSYS;
mncor1 = -pi_c();
mxcor1 = pi_c();
mncor2 = -pi_c()/2;
mxcor2 = pi_c()/2;
/.
We'll use equatorial and polar radii from
pck00010.tpc. These normally would be fetched
at run time, but for simplicity, we'll use
hard-coded values.
./
re = 13.0;
rp = 9.1;
f = ( re - rp ) / re;
corpar[0] = re;
corpar[1] = f;
}
/.
Compute plate model radius bounds.
./
printf ( "Computing %s bounds of plate set...\n",
cornam[corsys-1] );
dskrb2_c ( nv, vrtces, np, plates,
corsys, corpar, &mncor3, &mxcor3 );
printf ( "Done.\n" );
/.
Write the segment to the file.
./
printf ( "Writing segment...\n" );
dskw02_c ( handle,
center, surfid, dclass, frame, corsys,
corpar, mncor1, mxcor1, mncor2, mxcor2,
mncor3, mxcor3, first, last, nv,
vrtces, np, plates, spaixd, spaixi );
printf ( "Done.\n" );
}
/.
Segregate the data records in the DSK file and
close the file.
./
printf ( "Segregating and closing DSK file...\n" );
dskcls_c ( handle, SPICETRUE );
printf ( "Done.\n" );
return ( 0 );
}
When this program was executed on a Mac/Intel/cc/64-bit
platform, the output was:
Reading input data...
Done.
Creating segment 1
Creating spatial index...
Done.
Computing radius bounds of plate set...
Done.
Writing segment...
Done.
Creating segment 2
Creating spatial index...
Done.
Computing Z-coordinate bounds of plate set...
Done.
Writing segment...
Done.
Creating segment 3
Creating spatial index...
Done.
Computing altitude bounds of plate set...
Done.
Writing segment...
Done.
Segregating and closing DSK file...
Done.
Note that after run completion, a new DSK exists in the output
directory.
2) Close a new DSK file using DAS segregation. `handle'
is the DAS file handle of the DSK.
This is the normal choice for DSK creation.
dskcls_c ( HANDLE, SPICETRUE )
3) Close a new DSK file without using DAS segregation. The
close operation will be fast, but reading the file will be
less efficient than if the file had been segregated.
dskcls_c ( HANDLE, SPICEFALSE )
4) Close an existing DSK file that had been opened
for read access. In this case `optmiz' is ignored:
dskcls_c ( HANDLE, SPICEFALSE )
or
dskcls_c ( HANDLE, SPICETRUE )
Restrictions
1) This routine should not be called by user applications
that have loaded a DSK file via furnsh_c. Such applications
should call the functions unload_c or kclear_c instead.
Literature_ReferencesNone. Author_and_InstitutionN.J. Bachman (JPL) J. Diaz del Rio (ODC Space) Version
-CSPICE Version 1.0.1, 06-JUL-2021 (JDR)
Edited the header to comply with NAIF standard. Added
complete code example based on example in dskmi2_c.
-CSPICE Version 1.0.0, 23-JAN-2016 (NJB)
Index_Entriesclose a DSK file |
Fri Dec 31 18:41:04 2021