SDOT(3) BLAS routine of NEC Numeric Library Collection SDOT(3)
NAME
SDOT - BLAS level one, computes a dot product (inner product) of two
real vectors
SYNOPSIS
REAL FUNCTION SDOT ( n, x, incx, y, incy )
INTEGER n, incx, incy
REAL x, y
DESCRIPTION
SDOT computes a dot product of two real vectors (l real inner product).
2
This routine performs the following vector operation:
n
SDOT <-- (transpose of x) * y = Sum x(i)*y(i)
i=1
where x and y are real vectors.
If n <= 0, SDOT 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
SDOT REAL. 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 SDOT(3)