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

    Wed Apr  5 17:54:38 2017