dot(3F)

NAME
     SDOT, DDOT, CDOTC, ZDOTC, CDOTU, ZDOTU - Computes a dot product (inner
     product) of two real or complex vectors

SYNOPSIS
     Real

        dot = SDOT (n, x, incx, y, incy)

     Double precision

        dot = DDOT (n, x, incx, y, incy)

     Complex

        dot = CDOTC (n, x, incx, y,

        dot = CDOTU (n, x, incx, y, incy)

     Double complex

        dot = ZDOTC (n, x, incx, y, incy)

        dot = ZDOTU (n, x, incx, y, incy)

DESCRIPTION
     SDOT/DDOT computes a dot product of two real vectors (l2 real inner
     product).

     CDOTC/ZDOTC computes a dot product of the conjugate of a complex
     vector and another complex vector (l2 complex inner product).

     CDOTU/ZDOTU computes a dot product of two complex vectors.

     SDOT/DDOT and CDOTU/ZDOTU perform the following vector operation:

                         n
          dot <- xT y = Sum xi yi
                        i=1

     where x and y are real or complex vectors, and xT is the transpose of
     x.

     CDOTC/ZDOTC performs the following vector operation:

                         n   _
          dot <- xH y = Sum  xi yi
                        i=1

     where x and y are complex vectors, and xH is the conjugate transpose
     of x.

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

     These functions have the following arguments:

     dot   Result (dot product).  (output)
           SDOT: Real result.
           DDOT: Double precision result.
           CDOTC, CDOTU: Complex result.
           ZDOTC, ZDOTU: Double complex result.

     n     Integer.  (input)
           Number of elements in each vector.

     x     Array of dimension (n-1) * |incx| + 1.  (input)
           SDOT: Real array.
           DDOT: Double precision array.
           CDOTC, CDOTU: Complex array.
           ZDOTC, CDOTU: Double complex array.
           Array x contains the first vector operand.

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

     y     Array of dimension (n-1) * |incy| + 1.  (input)
           SDOT: Real array.
           DDOT: Double precision array.
           CDOTC, CDOTU: Complex array.
           ZDOTC, ZDOTU: Double complex array.
           Array y contains the second vector operand.

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

NOTES
     These routines are 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)