- Abstract
Given a number x and an array of non-decreasing numbers,
find the index of the largest array element less than x.
- Required_Reading
None.
- Brief_I/O
VARIABLE I/O DESCRIPTION
-------- --- --------------------------------------------------
x I Value to search against
n I Number elements in array
array I Array of possible lower bounds
The function returns the index of the last element of array that
is less than x.
- Detailed_Input
x Double precision number.
n Total number of elements in array.
array Array of double precision numbers which forms a
non-decreasing sequence. The elements of array need not be
distinct.
- Detailed_Output
The function returns the index of the highest-indexed element in the
input array that is less than x. The routine assumes the array elements
are sorted in non-decreasing order.
Indices range from 0 to n-1.
If all elements of the input array are greater than or equal to x,
the function returns -1.
- Parameters
None.
- Particulars
Note: If you need to find the first element of the array that
is greater than or equal to x, simply add 1 to the
result returned by this function and check to see if the
result is within the array bounds given by n.
- Examples
1) Let array be assigned the following values:
array[0] = -2.0;
array[1] = -2.0;
array[2] = 0.0;
array[3] = 1.0;
array[4] = 1.0;
array[5] = 11.0;
The table below demonstrates the behavior of lstltd_c:
Call Returned Value
=========================== ==============
lstltd_c ( -3.0, 6, array ) -1
lstltd_c ( -2.0, 6, array ) -1
lstltd_c ( 0.0, 6, array ) 1
lstltd_c ( 1.0, 6, array ) 2
lstltd_c ( 11.1, 6, array ) 5
- Restrictions
If the sequence of elements in array is not non-decreasing,
the program will run to completion but the index found will
not mean anything.
- Exceptions
Error free.
1) In the case that n is input with value less than or equal
to zero, the function returns -1.
2) If the input array is not sorted in increasing order, the
output of this routine are undefined. No error is signaled.
- Files
None.
- Author_and_Institution
N.J. Bachman (JPL)
W.L. Taber (JPL)
- Literature_References
None.
- Version
-CSPICE Version 1.0.0, 10-JUL-2002 (NJB) (WLT)
- Index_Entries
last d.p. element less_than
- Link to routine source