CSPICE_WNCOMD determines the complement of a double
precision window with respect to a specified interval.
For important details concerning this module's function, please refer to
the CSPICE routine wncomd_c.
Given:
left,
right the scalar, double precision left and right
endpoints of the complement interval.
window the scalar window to be complemented.
'window' must be created as a window structure
via a cspice_celld call.
the call:
cspice_wncomd, left, right, window, result
returns:
result the scalar output window, containing the complement
of 'window' with respect to the interval from 'left'
to 'right'. If 'result' is not large enough
to contain the result, as many intervals as will
fit are returned.
The user must create 'result' using cspice_celld.
'result' must be distinct from 'window'.
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.
;;
;; Create two cells each containing a double
;; precision 8vector.
;;
win1 = cspice_celld( 8 )
win2 = cspice_celld( 8 )
;;
;; Define a window with three intervals.
;;
darray = [ [ 1.d, 3.0], [ 7.0, 11.0], [23.0, 27.0] ]
;;
;; Add the window data to the cell.
;;
for i=0,2 do begin
cspice_wninsd, darray[0,i], darray[1,i], win1
endfor
;;
;; Do the complement.
;;
left = 2.d
right = 20.d
cspice_wncomd, 2.d0, 20.d0, win1, win2
;;
;; Calculate the number of intervals in the
;; return window 'win2'.
;;
no_intervals = cspice_wncard(win2)
;;
;; Output the intervals.
;;
for i= 0, (no_intervals 1 ) do begin
cspice_wnfetd, win2, i, left, right
print, left, right
endfor
IDL outputs:
3.0000000 7.0000000
11.000000 20.000000
The user must create any needed window structures with
cspice_celld prior to use regardless of whether the routine
uses the window as input or returns it as output.
ICY.REQ
CELLS.REQ
WINDOWS.REQ
Icy Version 1.0.2, 26NOV2007, EDW (JPL)
Implemented use of cspice_wncard function to return
window cardinality.
Icy Version 1.0.1, 12SEP2006, EDW (JPL)
Correct Required Reading citation CELL.REQ to CELLS.REQ.
Icy Version 1.0.0, 08AUG2004, EDW (JPL)
complement a d.p. window
