Abstract

   CSPICE_VEQU makes one double precision 3-dimensional vector equal to
   another.

I/O

   Given:

      vin      an arbitrary, double precision 3-dimensional vector.

               help, vin
                  DOUBLE = Array[3]

   the call:

      cspice_vequ, vin, vout

   returns:

      vout     a double precision 3-dimensional vector set equal to `vin'.

               help, vout
                  DOUBLE = Array[3]

Parameters

   None.

Examples

   Any numerical results shown for this example may differ between
   platforms as the results depend on the SPICE kernels used as input
   and the machine specific arithmetic implementation.

   1) Lets assume we have a pointing record that contains the
      start time of an interpolation interval, the components of
      the quaternion that represents the C-matrix associated with
      the start time of the interval, and the angular velocity vector
      of the interval. The following example demonstrates how to
      extract the time, the quaternion and the angular velocity
      vector into separate variables for their processing.


      Example code begins here.


      PRO vequ_ex1

         ;;
         ;; Define the pointing record. We would normally obtain it
         ;; from, e.g. CK readers, or other non SPICE data files.
         ;;
         record = [ 283480.753D0,    0.99999622D0, 0.D0, 0.D0,               $
                    -0.0027499965D0, 0.D0,         0.D0, 0.01D0 ]

         ;;
         ;; Get the time, quaternion and angular velocity vector
         ;; into separate variables.
         ;;
         time   = record[0]

         cspice_vequg, record[1:4], quat
         cspice_vequ,  record[5:7], av

         ;;
         ;; Display the contents of the variables.
         ;;
         print, format='(A,F11.3)', 'Time            :', time

         print, format='(A)', 'Quaternion      :'
         print, format='(4F15.10)', quat
         print, format='(A)', 'Angular velocity:'
         print, format='(3F15.10)', av

      END


      When this program was executed on a Mac/Intel/IDL8.x/64-bit
      platform, the output was:


      Time            : 283480.753
      Quaternion      :
         0.9999962200   0.0000000000   0.0000000000  -0.0027499965
      Angular velocity:
         0.0000000000   0.0000000000   0.0100000000

Particulars

   cspice_vequ simply sets each component of `vout' in turn equal to `vin'.
   No error checking is performed because none is needed.

   The IDL native code to perform the same operation:

      vout = vin

   The IDL '=' operator accepts arbitrary size vectors.

Exceptions

   1)  If the input argument `vin' is undefined, an error is signaled
       by the IDL error handling system.

   2)  If the input argument `vin' is not of the expected type, or it
       does not have the expected dimensions and size, an error is
       signaled by the Icy interface.

   3)  If the output argument `vout' is not a named variable, an
       error is signaled by the Icy interface.

Files

   None.

Restrictions

   None.

Required_Reading

   ICY.REQ

Literature_References

   None.

Author_and_Institution

   J. Diaz del Rio     (ODC Space)
   E.D. Wright         (JPL)

Version

   -Icy Version 1.0.2, 10-AUG-2021 (JDR)

       Edited the header to comply with NAIF standard. Added complete
       code examples.

       Added -Parameters, -Exceptions, -Files, -Restrictions,
       -Literature_References and -Author_and_Institution sections, and
       completed -Particulars section. Moved the contents of the existing
       -Examples section to -Particulars.

       Removed reference to the routine's corresponding CSPICE header from
       -Abstract section.

       Added arguments' type and size information in the -I/O section.

   -Icy Version 1.0.1, 09-DEC-2005 (EDW)

       Added -Examples section.

   -Icy Version 1.0.0, 16-JUN-2003 (EDW)

Index_Entries

   assign a 3-dimensional vector to another