- Abstract
Given a number x and an array of non-decreasing numbers,
find the index of the largest array element less than or equal
to 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 or equal to x.
- Detailed_Input
x Integer.
n Total number of elements in array.
array Array of integers 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 or equal to x. The routine assumes
the array elements are sorted in non-decreasing order.
Indices range from 0 to n-1.
If all elements of array are greater than x, this routine returns
the value -1.
- Parameters
None.
- Particulars
Note: If you need to find the first element of the array that
is greater than 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;
array[1] = -2;
array[2] = 0;
array[3] = 1;
array[4] = 1;
array[5] = 11;
The table below demonstrates the behavior of lstlei_c:
Call Returned Value
========================= ==============
lstlei_c ( -3, 6, array ) -1
lstlei_c ( -2, 6, array ) 1
lstlei_c ( 0, 6, array ) 2
lstlei_c ( 1, 6, array ) 4
lstlei_c ( 12, 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 integer element less_than_or_equal_to
- Link to routine source