Procedure

     VEQU ( Vector equality, 3 dimensions )

     SUBROUTINE VEQU ( VIN, VOUT )

Abstract

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

Required_Reading

     None.

Keywords

     ASSIGNMENT
     VECTOR

Declarations

     IMPLICIT NONE

     DOUBLE PRECISION  VIN   ( 3 )
     DOUBLE PRECISION  VOUT  ( 3 )

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 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
              IMPLICIT NONE

        C
        C     Local variables.
        C
              DOUBLE PRECISION      AV     ( 3 )
              DOUBLE PRECISION      QUAT   ( 4 )
              DOUBLE PRECISION      RECORD ( 8 )
              DOUBLE PRECISION      TIME

              INTEGER               I

        C
        C     Define the pointing record. We would normally obtain it
        C     from, e.g. CK readers or other non SPICE data files.
        C
              DATA                  RECORD  /
             .      283480.753D0,   0.99999622D0,  0.0D0,  0.0D0,
             .     -0.0027499965D0, 0.0D0,         0.0D0,  0.01D0 /

        C
        C     Get the time, quaternion and angular velocity vector
        C     into separate variables.
        C
              TIME = RECORD(1)

              CALL VEQUG  ( RECORD(2), 4, QUAT )
              CALL VEQU   ( RECORD(6),    AV   )

        C
        C     Display the contents of the variables.
        C
              WRITE(*,'(A,F11.3)') 'Time            :', TIME

              WRITE(*,'(A)')       'Quaternion      :'
              WRITE(*,'(4F15.10)')  QUAT
              WRITE(*,'(A)')       'Angular velocity:'
              WRITE(*,'(3F15.10)')  AV

              END


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

     J. Diaz del Rio    (ODC Space)
     W.M. Owen          (JPL)
     W.L. Taber         (JPL)

Version

    SPICELIB Version 1.1.0, 06-JUL-2021 (JDR)

        Added IMPLICIT NONE statement.

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

    SPICELIB Version 1.0.1, 10-MAR-1992 (WLT)

        Comment section for permuted index source lines was added
        following the header.

    SPICELIB Version 1.0.0, 31-JAN-1990 (WMO)