Procedure

   vequ_c ( Vector equality, 3 dimensions ) 

   void vequ_c ( ConstSpiceDouble   vin[3],
                 SpiceDouble        vout[3] )

Abstract

   Make one double precision 3-dimensional vector equal to
   another.

Required_Reading

   None.

Keywords

   ASSIGNMENT
   VECTOR

Brief_I/O

   VARIABLE  I/O  DESCRIPTION
   --------  ---  --------------------------------------------------
   vin        I   Double precision 3-dimensional vector.
   vout       O   Double precision 3-dimensional vector set equal
                  to `vin'.

Detailed_Input

   vin         is an arbitrary, double precision 3-dimensional vector.

Detailed_Output

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

Parameters

   None.

Exceptions

   Error free.

Files

   None.

Particulars

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

Examples

   The numerical results shown for this example may differ across
   platforms. The results depend on the SPICE kernels used as
   input, the compiler and supporting libraries, 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.


      /.
         Program vequ_ex1
      ./
      #include <stdio.h>
      #include "SpiceUsr.h"

      int main( )
      {

         /.
         Local variables.
         ./
         SpiceDouble          av     [3];
         SpiceDouble          quat   [4];
         SpiceDouble          time;

         /.
         Define the pointing record. We would normally obtain it
         from, e.g. CK readers or other non SPICE data files.
         ./
         SpiceDouble          record [8] = { 283480.753,        0.99999622,
                                                  0.0,          0.0,
                                                 -0.0027499965, 0.0,
                                                  0.0,          0.01 };

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

         vequg_c ( record+1, 4, quat );
         vequ_c  ( record+5,    av   );

         /.
         Display the contents of the variables.
         ./
         printf( "Time            : %10.3f\n", time );

         printf( "Quaternion      :\n" );
         printf( "%15.10f %14.10f %14.10f %14.10f\n",
                   quat[0], quat[1], quat[2], quat[3] );
         printf( "Angular velocity:\n" );
         printf( "%15.10f %14.10f %14.10f\n", av[0], av[1], av[2] );

         return ( 0 );
      }


      When this program was executed on a Mac/Intel/cc/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

Restrictions

   None.

Literature_References

   None.

Author_and_Institution

   N.J. Bachman        (JPL)
   J. Diaz del Rio     (ODC Space)
   W.M. Owen           (JPL)
   E.D. Wright         (JPL)

Version

   -CSPICE Version 1.1.1, 23-JUL-2020 (JDR)

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

   -CSPICE Version 1.1.0, 22-OCT-1998 (NJB)

       Made input vector const. Removed #include of SpiceZfc.h.

   -CSPICE Version 1.0.0, 08-FEB-1998 (EDW) (WMO)

Index_Entries

   assign a 3-dimensional vector to another