Visible to Intel only — GUID: GUID-7F8D9A7A-6A31-4B9E-B4E3-61D38D530E0E
Visible to Intel only — GUID: GUID-7F8D9A7A-6A31-4B9E-B4E3-61D38D530E0E
p?agemv
Computes a distributed matrix-vector product using absolute values for a general matrix.
Syntax
call psagemv(trans, m, n, alpha, a, ia, ja, desca, x, ix, jx, descx, incx, beta, y, iy, jy, descy, incy)
call pdagemv(trans, m, n, alpha, a, ia, ja, desca, x, ix, jx, descx, incx, beta, y, iy, jy, descy, incy)
call pcagemv(trans, m, n, alpha, a, ia, ja, desca, x, ix, jx, descx, incx, beta, y, iy, jy, descy, incy)
call pzagemv(trans, m, n, alpha, a, ia, ja, desca, x, ix, jx, descx, incx, beta, y, iy, jy, descy, incy)
Include Files
- mkl_pblas.h
Description
The p?agemv routines perform a distributed matrix-vector operation defined as
sub(y) := abs(alpha)*abs(sub(A)')*abs(sub(x)) + abs(beta*sub(y)),
or
sub(y) := abs(alpha)*abs(sub(A)')*abs(sub(x)) + abs(beta*sub(y)),
or
sub(y) := abs(alpha)*abs(conjg(sub(A)'))*abs(sub(x)) + abs(beta*sub(y)),
where
alpha and beta are scalars,
sub(A) is a m-by-n submatrix, sub(A) = A(ia:ia+m-1, ja:ja+n-1),
sub(x) and sub(y) are subvectors.
When trans = 'N' or 'n',
sub(x) denotes X(ix:ix, jx:jx+n-1) if incx = m_x, and
X(ix:ix+n-1, jx:jx) if incx = 1,
sub(y) denotes Y(iy:iy, jy:jy+m-1) if incy = m_y, and
Y(iy:iy+m-1, jy:jy) if incy = 1.
When trans = 'T' or 't', or 'C', or 'c',
sub(x) denotes X(ix:ix, jx:jx+m-1) if incx = m_x, and
X(ix:ix+m-1, jx:jx) if incx = 1,
sub(y) denotes Y(iy:iy, jy:jy+n-1) if incy = m_y, and
Y(iy:iy+m-1, jy:jy) if incy = 1.
Input Parameters
- trans
-
(global) CHARACTER*1. Specifies the operation:
if trans= 'N' or 'n', then sub(y) := |alpha|*|sub(A)|*|sub(x)| + |beta*sub(y)|
if trans= 'T' or 't', then sub(y) := |alpha|*|sub(A)'|*|sub(x)| + |beta*sub(y)|
if trans= 'C' or 'c', then sub(y) := |alpha|*|sub(A)'|*|sub(x)| + |beta*sub(y)|.
- m
-
(global) INTEGER. Specifies the number of rows of the distributed matrix sub(A), m≥0.
- n
-
(global) INTEGER. Specifies the number of columns of the distributed matrix sub(A), n≥0.
- alpha
-
(global)REAL for psagemv
DOUBLE PRECISION for pdagemv
COMPLEX for pcagemv
DOUBLE COMPLEX for pzagemv
Specifies the scalar alpha.
- a
-
(local)REAL for psagemv
DOUBLE PRECISION for pdagemv
COMPLEX for pcagemv
DOUBLE COMPLEX for pzagemv
Array, size (lld_a, LOCq(ja+n-1)). Before entry this array must contain the local pieces of the distributed matrix sub(A).
- ia, ja
-
(global) INTEGER. The row and column indices in the distributed matrix A indicating the first row and the first column of the submatrix sub(A), respectively.
- desca
-
(global and local) INTEGER array of dimension 9. The array descriptor of the distributed matrix A.
- x
-
(local)REAL for psagemv
DOUBLE PRECISION for pdagemv
COMPLEX for pcagemv
DOUBLE COMPLEX for pzagemv
Array, size (jx-1)*m_x + ix+(n-1)*abs(incx)) when trans = 'N' or 'n', and (jx-1)*m_x + ix+(m-1)*abs(incx)) otherwise.
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.
- beta
-
(global)REAL for psagemv
DOUBLE PRECISION for pdagemv
COMPLEX for pcagemv
DOUBLE COMPLEX for pzagemv
Specifies the scalar beta. When beta is set to zero, then sub(y) need not be set on input.
- y
-
(local)REAL for psagemv
DOUBLE PRECISION for pdagemv
COMPLEX for pcagemv
DOUBLE COMPLEX for pzagemv
Array, size (jy-1)*m_y + iy+(m-1)*abs(incy)) when trans = 'N' or 'n', and (jy-1)*m_y + iy+(n-1)*abs(incy)) otherwise.
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 the updated distributed vector sub(y).