Table of contents
CSPICE_WNELMD determines whether a point is an element
of a double precision window.
Given:
point a point, which may or may not be contained in one of the
intervals in `window'.
help, point
DOUBLE = Scalar
window a SPICE window containing zero or more intervals.
help, window
STRUCT = cspice_celld(2*N)
The user must create `window' using cspice_celld.
the call:
wnelmd = cspice_wnelmd( point, window )
returns:
wnelmd True if the input point is an element of the input window ---
that is, if
a[i] < point < b[i]
- -
for some interval [ a[i], b[i] ] in `window' --- and returns
False otherwise.
help, wnelmd
BOOLEAN = 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) Given a set of double precision numbers, determine whether they
are elements of a double precision window.
Example code begins here.
PRO wnelmd_ex1
;;
;; Create a cell containing a double precision
;; 8-vector.
;;
win1 = 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
test_array = [ 0.d, 1.d, 9.d, 13.d, 29.d ]
for i=0, n_elements(test_array) -1 do begin
if( cspice_wnelmd( test_array[i], win1) ) then begin
print, test_array[i], " - an element of the window"
endif else begin
print, test_array[i], " - not an element of the window"
endelse
endfor
END
When this program was executed on a Mac/Intel/IDL8.x/64-bit
platform, the output was:
0.0000000 - not an element of the window
1.0000000 - an element of the window
9.0000000 - an element of the window
13.000000 - not an element of the window
29.000000 - not an element of the window
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.
1) The cardinality of the input `window' must be even. Left
endpoints of stored intervals must be strictly greater than
preceding right endpoints. Right endpoints must be greater
than or equal to corresponding left endpoints. Invalid window
data are not diagnosed by this routine and may lead to
unpredictable results.
2) If any of the input arguments, `point' or `window', is
undefined, an error is signaled by the IDL error handling
system.
3) If any of the input arguments, `point' or `window', is not of
the expected type, or it does not have the expected dimensions
and size, an error is signaled by the Icy interface.
None.
None.
ICY.REQ
CELLS.REQ
WINDOWS.REQ
None.
J. Diaz del Rio (ODC Space)
E.D. Wright (JPL)
-Icy Version 1.0.2, 25-AUG-2021 (JDR)
Edited the header to comply with NAIF standard. Added
example's problem statement.
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 1.0.1, 12-SEP-2006 (EDW)
Correct Required Reading citation cell.req to cells.req.
-Icy Version 1.0.0, 08-AUG-2004 (EDW)
element of a d.p. window
|