## Developer Reference

Contents

Performs sum operation for two distributed general matrices.

## Syntax

Include Files
• mkl_pblas.h
Description
The
routines perform sum operation for two distributed general matrices. The operation is defined as
`sub(C):=beta*sub(C) + alpha*op(sub(A)),`
where:
op(
x
)
is one of
op(
x
) =
x
, or
op(
x
) =
x
'
,
alpha
and
beta
are scalars,
sub(
C
)
is an
m
-by-
n
distributed matrix,
sub(
C
)=
C
(
ic
:
ic
+
m
-1,
jc
:
jc
+
n
-1)
.
sub(
A
)
is a distributed matrix,
sub(
A
)=
A
(
ia
:
ia
+
n
-1,
ja
:
ja
+
m
-1)
.
Input Parameters
trans
(global) Specifies the operation:
if
trans
=
'N'
or
'n'
, then
op(sub(
A
)) := sub(
A
)
;
if
trans
=
'T'
or
't'
, then
op(sub(
A
)) := sub(
A
)
';
if
trans
=
'C'
or
'c'
, then
op(sub(
A
)) := sub(
A
)
'.
m
(global) Specifies the number of rows of the distributed matrix
sub(
C
)
and the number of columns of the submatrix
sub(
A
)
,
m
0.
n
(global) Specifies the number of columns of the distributed matrix
sub(
C
)
and the number of rows of the submatrix
sub(
A
)
,
n
0.
alpha
(global)
Specifies the scalar
alpha
.
a
(local)
Array, size
(
lld_a
, LOCq(
ja
+
m
-1))
. This array contains the local pieces of the distributed matrix
sub(
A
)
.
ia
,
ja
(global) 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) array of dimension 9. The array descriptor of the distributed matrix
A
.
beta
(global)
Specifies the scalar
beta
.
When
beta
is equal to zero, then
sub(
C
)
need not be set on input.
c
(local)
Array, size
(
lld_c
, LOCq(
jc
+
n
-1))
.
This array contains the local pieces of the distributed matrix
sub(
C
)
.
ic
,
jc
(global) The row and column indices in the distributed matrix
C
indicating the first row and the first column of the submatrix
sub(
C
)
, respectively.
descc
(global and local) array of dimension 9. The array descriptor of the distributed matrix
C
.
Output Parameters
c
Overwritten by the updated submatrix.

#### Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.