Procedure

   SpiceInt bsrchd_c ( SpiceDouble          value,
                       SpiceInt             ndim,
                       ConstSpiceDouble   * array ) 

Abstract

 
   Do a binary search for a key value within a double precision array, 
   assumed to be in increasing order. Return the index of the matching 
   array entry, or -1 if the key value is not found. 
 

Required_Reading

 
   None. 
 

Keywords

 
   ARRAY
   SEARCH 
 

Brief_I/O

 
   VARIABLE  I/O  DESCRIPTION 
   --------  ---  -------------------------------------------------- 
   value      I   Value to find in array. 
   ndim       I   Dimension of array. 
   array      I   Array to be searched. 

   The function returns the index of the input key value in the
   input array, or -1 if the value is not found.

Detailed_Input

 
   value       is the value to be found in the input array. 

   ndim        is the number of elements in the input array. 

   array       is the array to be searched. The elements in the
               array are assumed to sorted in increasing order. 

Detailed_Output

 
   The function returns the index of the input value in the input array. 
   Indices range from zero to ndim-1.

   If the input array does not contain the specified value, the function 
   returns -1. 
 
   If the input array contains more than one occurrence of the specified
   value, the returned index may point to any of the occurrences. 
 

Parameters

 
   None. 
 

Exceptions

 
   Error free. 

   If ndim < 1 the value of the function is -1. 

Files

 
   None. 

Particulars

 
   A binary search is performed on the input array. If an element of
   the array is found to match the input value, the index of that
   element is returned. If no matching element is found, -1 is
   returned.

Examples

 
   Let array contain the following elements: 

      -11.0
        0.0
       22.0
      750.0

   Then 

      bsrchd_c ( -11.0, 4, array )   ==  0
      bsrchd_c (  22.0, 4, array )   ==  2 
      bsrchd_c ( 751.0, 4, array )   == -1 

Restrictions

 
   array is assumed to be sorted in increasing order. If this 
   condition is not met, the results of bsrchd_c are unpredictable. 
 

Literature_References

 
   None. 
 

Author_and_Institution

 
   N.J. Bachman    (JPL)
   I.M. Underwood  (JPL) 
 

Version

 
   -CSPICE Version 1.0.0, 22-AUG-2002 (NJB) (IMU)

Index_Entries

 
   binary search for a double precision value 
 

Link to routine bsrchd_c source file bsrchd_c.c