Developer Reference

  • 2020.2
  • 07/15/2020
  • Public Content
Contents

p?herk

Performs a rank-k update of a distributed Hermitian matrix.

Syntax

call pcherk
(
uplo
,
trans
,
n
,
k
,
alpha
,
a
,
ia
,
ja
,
desca
,
beta
,
c
,
ic
,
jc
,
descc
)
call pzherk
(
uplo
,
trans
,
n
,
k
,
alpha
,
a
,
ia
,
ja
,
desca
,
beta
,
c
,
ic
,
jc
,
descc
)
Include Files
  • mkl_pblas.h
Description
The
p?herk
routines perform a distributed matrix-matrix operation defined as
sub(
C
):=
alpha
*sub(
A
)*conjg(sub(
A
)')+
beta
*sub(
C
),
or
sub(
C
):=
alpha
*conjg(sub(
A
)')*sub(
A
)+
beta
*sub(
C
),
where:
alpha
and
beta
are scalars,
sub(
C
)
is an
n
-by-
n
Hermitian distributed matrix,
sub(
C
)=C(
ic
:
ic
+
n
-1,
jc
:
jc
+
n
-1)
.
sub(
A
)
is a distributed matrix,
sub(
A
)=
A
(
ia
:
ia
+
n
-1,
ja
:
ja
+
k
-1)
, if
trans
= '
N
'
or
'
n
'
, and
sub(
A
)=
A
(
ia
:
ia
+
k
-1,
ja
:
ja
+
n
-1)
otherwise.
Input Parameters
uplo
(global)
CHARACTER*1
.
Specifies whether the upper or lower triangular part of the Hermitian distributed matrix
sub(
C
)
is used:
If
uplo
=
'U'
or
'u'
, then the upper triangular part of the
sub(
C
)
is used.
If
uplo
=
'L'
or
'l'
, then the low triangular part of the
sub(
C
)
is used.
trans
(global)
CHARACTER*1
.
Specifies the operation:
if
trans
=
'N'
or
'n'
, then
sub(
C
) :=
alpha
*sub(
A
)*conjg(sub(
A
)') +
beta
*sub(
C
)
;
if
trans
=
'C'
or
'c'
, then
sub(
C
) :=
alpha
*conjg(sub(
A
)')*sub(
A
) +
beta
*sub(
C
)
.
n
(global)
INTEGER
.
Specifies the order of the distributed matrix
sub(
C
)
,
n
0.
k
(global)
INTEGER
.