void wncond_c ( SpiceDouble left,
SpiceCell * window )
Contract each of the intervals of a double precision window.
VARIABLE I/O DESCRIPTION
-------- --- --------------------------------------------------
left I Amount added to each left endpoint.
right I Amount subtracted from each right endpoint.
window I,O Window to be contracted.
left is the amount to be added to the left endpoint of
each interval in the input window.
right is the amount to be subtracted from the right
endpoint of each interval in the window.
window on input, is a CSPICE window containing zero or more
intervals. window must be declared as a double precision
window on output, is the original window with each of its
intervals contracted by left units on the left and
right units on the right.
1) If the input window does not have double precision type,
the error SPICE(TYPEMISMATCH) is signaled.
This routine contracts (shortens) each of the intervals in
the input window. The adjustments are not necessarily symmetric.
That is, left units are added to the left endpoint of each
interval, and right units are subtracted from the right endpoint
of each interval, where left and right may be different.
Intervals are dropped when they are contracted by amounts
greater than their measures.
Let window contain the intervals
[ 1, 3 ] [ 7, 11 ] [ 23, 27 ] [ 29, 29 ]
Then the following series of calls
wncond_c ( 2, 1, &window ); (1)
wncond_c ( -2, 2, &window ); (2)
wncond_c ( -2, -1, &window ); (3)
produces the following series of windows
[ 9, 10 ] [ 25, 26 ] (1)
[ 7, 8 ] [ 23, 24 ] (2)
[ 5, 9 ] [ 21, 25 ] (3)
Note that intervals may be "contracted" by negative amounts.
In the example above, the second call shifts each interval to
the left, while the third call undoes the effect of the first
call (without restoring the destroyed intervals).
Note also that the third call is exactly equivalent to the
wnexpd_c ( 2, 1, window );
N.J. Bachman (JPL)
H.A. Neilan (JPL)
W.L. Taber (JPL)
I.M. Underwood (JPL)
-CSPICE Version 1.0.0, 21-JUL-2002 (NJB) (HAN) (WLT) (IMU)
contract the intervals of a d.p. window