Table of contents
CSPICE_DSKOPN opens a new DSK file, returning the handle
of the opened file.
Given:
fname the name of the DSK file to open.
help, fname
STRING = Scalar
ifname the descriptive internal filename for the DSK.
help, ifname
STRING = Scalar
ncomch the scalar integer number of characters to reserve for comments.
help, ncomch
LONG = Scalar
the call:
cspice_dskopn, fname, ifname, ncomch, handle
returns:
handle the file handle assigned to 'fname'.
help, handle
LONG = Scalar
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 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 vertices data. This file has one segment only.
phobos_3_3.bds
Example code begins here.
PRO dskopn_ex1
;;
;; IcyUser globally defines DSK parameters.
;; For more information, please see IcyUser.pro and
;; IcyDSK.pro.
;;
@IcyUser
SPICETRUE = 1L
NSEG = 3
cornam = [ 'radius', 'Z-coordinate', 'Z-coordinate', 'altitude']
;;
;; Assign names of input and output DSK files.
;;
indsk = 'phobos_3_3.bds'
dsk = 'phobos_3_3_3seg.bds'
if ( cspice_exists(dsk) ) then begin
file_delete, dsk
endif
;;
;; Open input DSK for read access; find first segment.
;;
cspice_dasopr, indsk, inhan
cspice_dlabfs, inhan, dladsc, found
;;
;; Fetch vertices and plates from input DSK file.
;;
;; Note that vertex and plate indices are 1-based.
;;
print, 'Reading input data...'
cspice_dskv02, inhan, dladsc, 1, SPICE_DSK02_MAXVRT, vrtces
cspice_dskp02, inhan, dladsc, 1, SPICE_DSK02_MAXPLT, plates
print, 'Done.'
;;
;; Set input array sizes required by cspice_dskmi2.
;;
voxpsz = SPICE_DSK02_MAXVXP
voxlsz = SPICE_DSK02_MXNVLS
worksz = SPICE_DSK02_MAXCEL
spaisz = SPICE_DSK02_SPAISZ
makvtl = SPICETRUE
;;
;; Set fine and coarse voxel scales. (These usually
;; need to determined by experimentation.)
;;
finscl = 5.D
corscl = 4
;;
;; Open a new DSK file.
;;
cspice_dskopn, dsk, dsk, 0, handle
for segno=1, NSEG do begin
;;
;; Create spatial index. We won't generate a
;; vertex-plate mapping, so we set the flag
;; for creating this map to "false."
;;
print, 'Creating segment ', segno
print, 'Creating spatial index...'
cspice_dskmi2, vrtces, plates, finscl, corscl, $
worksz, voxpsz, voxlsz, makvtl, $
spaisz, spaixd, spaixi
print, 'Done.'
;;
;; 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.D * cspice_jyear()
last = 50.D * cspice_jyear()
;;
;; Set the coordinate system and coordinate system
;; bounds based on the segment index.
;;
;; Zero out the coordinate parameters to start.
;;
corpar = dblarr(SPICE_DSK_NSYPAR)
case segno of
1 : begin
;;
;; Use planetocentric latitudinal coordinates. Set
;; the longitude and latitude bounds.
;;
corsys = SPICE_DSK_LATSYS
mncor1 = -cspice_pi()
mxcor1 = cspice_pi()
mncor2 = -cspice_halfpi()
mxcor2 = cspice_halfpi()
end
2 : begin
;;
;; 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 = -1.3D
mxcor1 = 1.31D
mncor2 = -1.21D
mxcor2 = 1.2D
end
3 : begin
;;
;; Set the coordinate system to planetodetic.
;;
corsys = SPICE_DSK_PDTSYS
mncor1 = -cspice_pi()
mxcor1 = cspice_pi()
mncor2 = -cspice_halfpi()
mxcor2 = cspice_halfpi()
;;
;; 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.D0
rp = 9.1D
f = ( re - rp ) / re
corpar = [ re, f ]
end
else: message, 'Icy(BUG)'
endcase
;;
;; Compute plate model radius bounds.
;;
print, 'Computing ' + cornam[corsys-1] +' bounds of plate set...'
cspice_dskrb2, vrtces, plates, corsys, corpar, mncor3, mxcor3
print, 'Done.'
;;
;; Write the segment to the file.
;;
print, 'Writing segment...'
cspice_dskw02, handle, $
center, $
surfid, $
dclass, $
frame, $
corsys, $
corpar, $
mncor1, $
mxcor1, $
mncor2, $
mxcor2, $
mncor3, $
mxcor3, $
first, $
last, $
vrtces, $
plates, $
spaixd, $
spaixi
end
;;
;; Close the input DSK.
;;
cspice_dskcls, handle, SPICETRUE
cspice_dascls, inhan
END
When this program was executed on a Mac/Intel/IDL8.x/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...
Creating segment 2
Creating spatial index...
Done.
Computing Z-coordinate bounds of plate set...
Done.
Writing segment...
Creating segment 3
Creating spatial index...
Done.
Computing altitude bounds of plate set...
Done.
Writing segment...
Note that after run completion, a new DSK exists in the output
directory.
A cspice_dskcls call should balance every cspice_dskopn
call.
1) If the input filename is blank, an error is signaled by a
routine in the call tree of this routine. No file will be
created.
2) If the specified file cannot be opened without exceeding the
maximum allowed number of open DAS files, an error is signaled
by a routine in the call tree of this routine. No file will be
created.
3) If the file cannot be opened properly, an error is signaled by
a routine in the call tree of this routine. No file will be
created.
4) If the initial records in the file cannot be written, an error
is signaled by a routine in the call tree of this routine. No
file will be created.
5) If no logical units are available, an error is signaled by a
routine in the call tree of this routine. No file will be
created.
6) If the internal file name contains nonprinting characters
(ASCII codes decimal 0-31 and 127-255), an error is signaled
by a routine in the call tree of this routine. No file will be
created.
7) If the number of comment characters allocated `ncomch' is
negative, an error is signaled by a routine in the call
tree of this routine. No file will be created.
8) If any of the input arguments, `fname', `ifname' or `ncomch',
is undefined, an error is signaled by the IDL error handling
system.
9) If any of the input arguments, `fname', `ifname' or `ncomch',
is not of the expected type, or it does not have the expected
dimensions and size, an error is signaled by the Icy
interface.
10) If the output argument `handle' is not a named variable, an
error is signaled by the Icy interface.
See argument `fname'.
None.
ICY.REQ
DAS.REQ
DSK.REQ
None.
J. Diaz del Rio (ODC Space)
M. Liukis (JPL)
E.D. Wright (JPL)
-Icy Version 1.0.1, 05-DEC-2021 (JDR)
Edited the -Examples section to comply with NAIF standard.
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 1.0.0, 14-DEC-2016 (ML) (EDW)
open a new DSK file
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