Table of contents
CSPICE_WNEXPD expands each of the intervals of a double
precision window.
Given:
left amount to subtract from each left interval endpoint in the
input 'window'
[1,1] = size(left); double = class(left)
right amount to add to each right interval endpoint in the input
'window'
[1,1] = size(right); double = class(right)
window SPICE window containing zero or more intervals.
[2m,1] = size(window); double = class(window)
the call:
window_f = cspice_wnexpd( left, right, window)
returns:
window_f SPICE window containing zero or more intervals, representing
the original 'window' with each of its intervals expanded by
'left' units on the left and 'right' units on the right
[2n,1] = size(window_f); double = class(window_f)
'window_f' can overwrite 'window'.
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 double precision window, containing the following four
intervals:
[ 1.0, 3.0 ], [ 7.0, 11.0 ], [ 23.0, 27.0 ], [ 29.0, 29.0 ]
expand each interval by 2.0 units on the left and 1.0 on the
right endpoints, then by -2.0 units on the left and 2.0 units on
the right, and finally -2.0 units on the left and -1.0 units on
the right.
Example code begins here.
function wnexpd_ex1()
%
% Let 'window' contain the intervals
%
window = [ [ 1; 3 ]; [ 7; 11 ]; [ 23; 27 ]; [ 29; 29 ]; ];
%
% Apply the following series of calls
%
window = cspice_wnexpd( 2, 1, window );
fprintf( '1: Expanded window by 2 (left) and 1 (right)\n' );
for i=1:cspice_wncard(window)
[left, right] = cspice_wnfetd( window, i );
fprintf( '%16.6f %16.6f\n', left, right );
end
window = cspice_wnexpd( -2, 2, window );
fprintf( '2: Expanded window by -2 (left) and 2 (right)\n' );
for i=1:cspice_wncard(window)
[left, right] = cspice_wnfetd( window, i );
fprintf( '%16.6f %16.6f\n', left, right );
end
window = cspice_wnexpd( -2, -1, window );
fprintf( '3: Expanded window by -2 (left) and -1 (right)\n' );
for i=1:cspice_wncard(window)
[left, right] = cspice_wnfetd( window, i );
fprintf( '%16.6f %16.6f\n', left, right );
end
When this program was executed on a Mac/Intel/Octave6.x/64-bit
platform, the output was:
1: Expanded window by 2 (left) and 1 (right)
-1.000000 4.000000
5.000000 12.000000
21.000000 30.000000
2: Expanded window by -2 (left) and 2 (right)
1.000000 6.000000
7.000000 14.000000
23.000000 32.000000
3: Expanded window by -2 (left) and -1 (right)
3.000000 5.000000
9.000000 13.000000
25.000000 31.000000
Note that intervals may be "expanded" by negative amounts.
In the example above, the second call shifts each interval to
the right, while the third call undoes the effect of the first
call (without restoring the merged intervals).
Note also that the third call is exactly equivalent to the
call:
cspice_wncond( 2, 1, window )
This function expands (lengthens) each of the intervals in
the input window. The adjustments are not necessarily symmetric.
That is, left units are subtracted from the left endpoint of
each interval, and right units are added to the right endpoint
of each interval, where left and right may be different.
Intervals are merged when expansion causes them to overlap.
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, `left', `right' or `window', is
undefined, an error is signaled by the Matlab error handling
system.
3) If any of the input arguments, `left', `right' or `window', is
not of the expected type, or it does not have the expected
dimensions and size, an error is signaled by the Mice
interface.
None.
None.
MICE.REQ
WINDOWS.REQ
None.
J. Diaz del Rio (ODC Space)
S.C. Krening (JPL)
E.D. Wright (JPL)
-Mice Version 1.1.0, 10-AUG-2021 (EDW) (JDR)
Edited the header to comply with NAIF standard. Added
example's problem statement and reformatted example's output.
Added -Parameters, -Exceptions, -Files, -Restrictions,
-Literature_References and -Author_and_Institution sections, and
completed -Particulars section.
Eliminated use of "lasterror" in rethrow.
Removed reference to the function's corresponding CSPICE header from
-Required_Reading section.
-Mice Version 1.0.1, 12-MAR-2012 (EDW) (SCK)
Edited -I/O section to conform to NAIF standard for Mice
documentation.
-Mice Version 1.0.0, 24-JUL-2007 (EDW)
expand the intervals of a d.p. window
|