Procedure

   void wnfetd_c ( SpiceCell    * window,
                   SpiceInt       n,
                   SpiceDouble  * left,
                   SpiceDouble  * right   ) 

Abstract

 
   Fetch a particular interval from a double precision window. 
 

Required_Reading

 
   WINDOWS 
 

Keywords

 
   WINDOWS 
 

Brief_I/O

   VARIABLE  I/O  DESCRIPTION 
   --------  ---  -------------------------------------------------- 
   window     I   Input window. 
   n          I   Index of interval to be fetched. 
   left, 
   right      O   Left, right endpoints of the nth interval. 

Detailed_Input

   window      is a window containing zero or more intervals. 

               window must be declared as a double precision SpiceCell.

   n           is the index of a particular interval within the 
               window.  Indices range from 0 to N-1, where N is the
               number of intervals in the window.

Detailed_Output

   left, 
   right       are the left and right endpoints of the nth interval 
               in the input window.   
 

Parameters

 
   None. 
 

Exceptions

 
   1) If the input window does not have double precision type,
      the error SPICE(TYPEMISMATCH) signals.

   2) If n is less than zero, the error SPICE(NOINTERVAL) is 
      signaled. 
 
   3) If the interval does not exist, i.e., n >= card_c(&window)/2, 
      the error SPICE(NOINTERVAL) signals. 
 

Files

 
   None. 

Particulars

 
   None. 
 

Examples

 
   Let window contain the intervals 

      [ 1, 3 ]  [ 7, 11 ]  [ 23, 27 ] 

   This window has a cardinality of 6 ( N=3 intervals), so 'n' may have
   value 0, 1, or 2, (n < cardinality/2)

   Then the following calls 

      wnfetd_c ( &window,  0, &left, &right );    (1) 
      wnfetd_c ( &window,  1, &left, &right );    (2) 
      wnfetd_c ( &window,  2, &left, &right );    (3) 

   yield the following values of left and right 

      left         right 
      ---------    --------- 
      1            3 
      7            11 
      23           27 

Restrictions

 
   None. 
 

Literature_References

 
   None. 
 

Author_and_Institution

 
   N.J. Bachman    (JPL)
   W.L. Taber      (JPL) 
   I.M. Underwood  (JPL) 
 

Version

   -CSPICE Version 1.0.2, 30-JUL-2007 (EDW)

      Removed erroneous description in the Examples section 
      indicating "Undefined" as a return state after an error
      event caused by an invalid value of n.
 
   -CSPICE Version 1.0.0, 22-AUG-2002 (NJB) (WLT) (IMU)

Index_Entries

 
   fetch an interval from a d.p. window 
 

Link to routine wnfetd_c source file wnfetd_c.c