Procedure

     VSCLG ( Vector scaling, general dimension )

     SUBROUTINE VSCLG ( S, V1, NDIM, VOUT )

Abstract

     Multiply a scalar and a double precision vector of arbitrary
     dimension.

Required_Reading

     None.

Keywords

     VECTOR

Declarations

     IMPLICIT NONE

     INTEGER            NDIM
     DOUBLE PRECISION   S
     DOUBLE PRECISION   V1   ( NDIM )
     DOUBLE PRECISION   VOUT ( NDIM )

Brief_I/O

     VARIABLE  I/O  DESCRIPTION
     --------  ---  --------------------------------------------------
     S          I   Scalar to multiply a vector.
     V1         I   Vector to be multiplied.
     NDIM       I   Dimension of V1 (and also VOUT).
     VOUT       O   Product vector, S * V1.

Detailed_Input

     S        is a double precision scalar.

     V1       is a double precision n-dimensional vector.

     NDIM     is the dimension of V1 (and VOUT).

Detailed_Output

     VOUT     is a double precision n-dimensional vector containing
              the product of the scalar with the vector V1.

Parameters

     None.

Exceptions

     Error free.

Files

     None.

Particulars

     For each value of the index I from 1 to NDIM, this subroutine
     performs the following multiplication

        VOUT(I) = S * V1(I)

     No error checking is performed to guard against numeric overflow
     or underflow.

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) Define a sets of scalar double precision values and use them
        to scale a given n-dimensional vector.


        Example code begins here.


              PROGRAM VSCLG_EX1
              IMPLICIT NONE

        C
        C     Local parameters.
        C
              INTEGER               NDIM
              PARAMETER           ( NDIM   = 4 )

              INTEGER               SETSIZ
              PARAMETER           ( SETSIZ = 3 )

        C
        C     Local variables.
        C
              DOUBLE PRECISION      S    ( SETSIZ )
              DOUBLE PRECISION      V1   ( NDIM   )
              DOUBLE PRECISION      VOUT ( NDIM   )

              INTEGER               I

        C
        C     Define the set of scalars and the input vector.
        C
              DATA                  S    / 3.D0, 0.D0, -1.D0 /

              DATA                  V1   / 1.D0, 2.D0, -3.D0, 4.D0  /


              WRITE(*,'(A,4F6.1)') 'Input vector : ', V1
              WRITE(*,*)

        C
        C     Calculate product of each scalar and V1.
        C
              DO I=1, SETSIZ

                 CALL VSCLG ( S(I), V1, NDIM, VOUT )

                 WRITE(*,'(A,F6.1)')  'Scale factor : ', S(I)
                 WRITE(*,'(A,4F6.1)') 'Output vector: ', VOUT
                 WRITE(*,*)

              END DO

              END


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


        Input vector :    1.0   2.0  -3.0   4.0

        Scale factor :    3.0
        Output vector:    3.0   6.0  -9.0  12.0

        Scale factor :    0.0
        Output vector:    0.0   0.0  -0.0   0.0

        Scale factor :   -1.0
        Output vector:   -1.0  -2.0   3.0  -4.0

Restrictions

     1)  No error checking is performed to guard against numeric
         overflow. The programmer is thus required to insure that the
         values in V1 and S are reasonable and will not cause overflow.

Literature_References

     None.

Author_and_Institution

     N.J. Bachman       (JPL)
     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 based on existing example.

    SPICELIB Version 1.0.2, 22-APR-2010 (NJB)

        Header correction: assertions that the output
        can overwrite the input have been removed.

    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)