DSDOT(3)        BLAS routine of NEC Numeric Library Collection        DSDOT(3)



NAME
       DSDOT  -  BLAS level one, computes a dot product (inner product) of two
       real vectors in double precision

SYNOPSIS
       DOUBLE PRECISION FUNCTION DSDOT ( n, x, incx, y, incy )

           INTEGER          n, incx, incy

           REAL             x, y


DESCRIPTION
       DSDOT computes a dot product of two real vectors (l  real inner
       product) in double precision.                      2

       This routine performs the following vector operation:

                                                    n
              DSDOT  <--  (transpose of x) * y  =  Sum  x(i)*y(i)
                                                   i=1
       where x and y are real vectors.

       If n <= 0, DSDOT is set to 0.

ARGUMENTS
       n       INTEGER. (input)
               Number of elements in each vector.

       x       REAL. (input)
               Array of dimension (n-1) * |incx| + 1.
               Array x contains the first vector operand.

       incx    INTEGER. (input)
               Increment between elements of x.
               If incx = 0, the results will be unpredictable.

       y       REAL. (input)
               Array of dimension (n-1) * |incy| + 1.
               Array y contains the second vector operand.

       incy    INTEGER. (input)
               Increment between elements of y.  If incy = 0, the results will
               be unpredictable.

RETURN VALUES
       DSDOT   DOUBLE PRECISION. Result (dot product). (output)

NOTES
       This  routine  is  Level  1  Basic  Linear Algebra Subprograms (Level 1
       BLAS).

       When working backward (incx < 0 or incy < 0), each  routine  starts  at
       the end of the vector and moves backward, as follows:

            x(1-incx * (n-1)), x(1-incx * (n-2)), ..., x(1)

            y(1-incy * (n-1)), y(1-incy * (n-2)), ..., y(1)



BLAS routine                                                          DSDOT(3)