lstlei_c

Index Page lstlei_c
A B C D E F G H I J K L M N O P Q R S T U V W X
Procedure Abstract Required_Reading Keywords Brief_I/O Detailed_Input | Detailed_Output Parameters Exceptions Files Particulars Examples | Restrictions Literature_References Author_and_Institution Version Index_Entries
#### Procedure
       SpiceInt lstlei_c ( SpiceInt            x,
                           SpiceInt            n,
                           ConstSpiceInt     * array )
#### 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.
#### Keywords
       SEARCH,  ARRAY
#### 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.
#### 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.
#### 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.
#### Literature_References
       None.
#### Author_and_Institution
       N.J. Bachman    (JPL)
       W.L. Taber      (JPL)
#### Version
       -CSPICE Version 1.0.0, 10-JUL-2002 (NJB) (WLT)
#### Index_Entries
       last integer element less_than_or_equal_to
#### Link to routine lstlei_c source file lstlei_c.c

    Thu Apr 16 08:58:31 2009