Visible to Intel only — GUID: GUID-99E2F3BB-22F8-4DA9-BE4C-1FBE921623A7
Visible to Intel only — GUID: GUID-99E2F3BB-22F8-4DA9-BE4C-1FBE921623A7
p?axpy
Computes a distributed vector-scalar product and adds the result to a distributed vector.
Syntax
call psaxpy(n, a, x, ix, jx, descx, incx, y, iy, jy, descy, incy)
call pdaxpy(n, a, x, ix, jx, descx, incx, y, iy, jy, descy, incy)
call pcaxpy(n, a, x, ix, jx, descx, incx, y, iy, jy, descy, incy)
call pzaxpy(n, a, x, ix, jx, descx, incx, y, iy, jy, descy, incy)
Include Files
- mkl_pblas.h
Description
The p?axpy routines perform the following operation with distributed vectors:
sub(y) := sub(y) + a*sub(x)
where:
a is a scalar;
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.
- a
-
(local) REAL for psaxpy
DOUBLE PRECISION for pdaxpy
COMPLEX for pcaxpy
DOUBLE COMPLEX for pzaxpy
Specifies the scalar a.
- x
-
(local) REAL for psaxpy
DOUBLE PRECISION for pdaxpy
COMPLEX for pcaxpy
DOUBLE COMPLEX for pzaxpy
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 psaxpy
DOUBLE PRECISION for pdaxpy
COMPLEX for pcaxpy
DOUBLE COMPLEX for pzaxpy
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
- y
-
Overwritten by sub(y) := sub(y) + a*sub(x).