Developer Reference

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

?sfrk

Performs a symmetric rank-k operation for matrix in RFP format.

Syntax

call ssfrk
(
transr
,
uplo
,
trans
,
n
,
k
,
alpha
,
a
,
lda
,
beta
,
c
)
call dsfrk
(
transr
,
uplo
,
trans
,
n
,
k
,
alpha
,
a
,
lda
,
beta
,
c
)
Include Files
  • mkl.fi
Description
The
?sfrk
routines perform a matrix-matrix operation using symmetric matrices. The operation is defined as
C
:=
alpha
*
A
*
A
T
+
beta
*
C
,
or
C
:=
alpha
*
A
T
*
A
+
beta
*
C
,
where:
alpha
and
beta
are scalars,
C
is an
n
-by-
n
symmetric matrix in rectangular full packed (RFP) format,
A
is an
n
-by-
k
matrix in the first case and a
k
-by-
n
matrix in the second case.
Input Parameters
transr
CHARACTER*1
.
if
transr
= 'N'
or
'n'
, the normal form of RFP
C
is stored;
if
transr
= 'T'
or
't'
, the transpose form of RFP
C
is stored.
uplo
CHARACTER*1
.
Specifies whether the upper or lower triangular part of the array
c
is used.
If
uplo
=
'U'
or
'u'
, then the upper triangular part of the array
c
is used.
If
uplo
=
'L'
or
'l'
, then the low triangular part of the array
c
is used.
trans
CHARACTER*1
.
Specifies the operation:
if
trans
= 'N'
or
'n'
, then
C
:=
alpha
*
A
*
A
T
+
beta
*
C
;
if
trans
= 'T'
or
't'
, then
C
:=
alpha
*
A
T
*
A
+
beta
*
C
;
n
INTEGER
.
Specifies the order of the matrix
C
. The value of
n
must be at least zero.
k
INTEGER
.
On entry with
trans
=
'N'
or
'n'
,
k
specifies the number of columns of the matrix
A
, and on entry with
trans
=
'T'
or
't'
,
k
specifies the number of rows of the matrix
A
.
The value of
k
must be at least zero.
alpha
REAL
for
ssfrk
DOUBLE PRECISION
for
dsfrk
Specifies the scalar
alpha
.
a
REAL
for
ssfrk
DOUBLE PRECISION
for
dsfrk
Array,
DIMENSION
(
lda
,
ka
)
, where
ka
is
k
when
trans
=
'N'
or
'n'
, and is
n
otherwise. Before entry with
trans
=
'N'
or
'n'
, the leading
n
-by-
k
part of the array
a
must contain the matrix
A
, otherwise the leading
k
-by-
n
part of the array
a
must contain the matrix
A
.
lda
INTEGER
. Specifies the leading dimension of
a
as declared in the calling (sub)program. When
trans
=
'N'
or