Visible to Intel only — GUID: GUID-F0992C6B-2DC3-4B3F-A5B2-00F0641DE3B8
Visible to Intel only — GUID: GUID-F0992C6B-2DC3-4B3F-A5B2-00F0641DE3B8
p?dot
Computes the dot product of two distributed real vectors.
Syntax
call psdot(n, dot, x, ix, jx, descx, incx, y, iy, jy, descy, incy)
call pddot(n, dot, x, ix, jx, descx, incx, y, iy, jy, descy, incy)
Include Files
- mkl_pblas.h
Description
The ?dot functions compute the dot product dot of two distributed real vectors defined as
dot = sub(x)'*sub(y)
where sub(x) and sub(y) are n-element distributed vectors.
sub(x) denotes X(ix, jx:jx+n-1) if incx=m_x, and X(ix: ix+n-1, jx) if incx= 1;
sub(y) denotes Y(iy, jy:jy+n-1) if incy=m_y, and Y(iy: iy+n-1, jy) if incy= 1.
Input Parameters
- n
-
(global) INTEGER. The length of distributed vectors, n≥0.
- x
-
(local) REAL for psdot
DOUBLE PRECISION for pddot
Array, size (jx-1)*m_x + ix+(n-1)*abs(incx)).
This array contains the entries of the distributed vector sub(x).
- ix, jx
-
(global) INTEGER. The row and column indices in the distributed matrix X indicating the first row and the first column of the submatrix sub(X), respectively.
- descx
-
(global and local) INTEGER array of dimension 9. The array descriptor of the distributed matrix X.
- incx
-
(global) INTEGER. Specifies the increment for the elements of sub(x). Only two values are supported, namely 1 and m_x. incx must not be zero.
- y
-
(local)REAL for psdot
DOUBLE PRECISION for pddot
Array, size (jy-1)*m_y + iy+(n-1)*abs(incy)).
This array contains the entries of the distributed vector sub(y).
- iy, jy
-
(global) INTEGER. The row and column indices in the distributed matrix Y indicating the first row and the first column of the submatrix sub(Y), respectively.
- descy
-
(global and local) INTEGER array of dimension 9. The array descriptor of the distributed matrix Y.
- incy
-
(global) INTEGER. Specifies the increment for the elements of sub(y). Only two values are supported, namely 1 and m_y. incy must not be zero.
Output Parameters
- dot
-
(local) REAL for psdot
DOUBLE PRECISION for pddot
Dot product of sub(x) and sub(y) only in their scope.