Developer Reference

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

?ormrq

Multiplies a real matrix by the orthogonal matrix Q of the RQ factorization formed by
?gerqf
.

Syntax

call sormrq
(
side
,
trans
,
m
,
n
,
k
,
a
,
lda
,
tau
,
c
,
ldc
,
work
,
lwork
,
info
)
call dormrq
(
side
,
trans
,
m
,
n
,
k
,
a
,
lda
,
tau
,
c
,
ldc
,
work
,
lwork
,
info
)
call ormrq
(
a
,
tau
,
c
[
,
side
]
[
,
trans
]
[
,
info
]
)
Include Files
  • mkl.fi
    ,
    lapack.f90
Description
The routine multiplies a real
m
-by-
n
matrix
C
by
Q
or
Q
T
, where
Q
is the real orthogonal matrix defined as a product of
k
elementary reflectors
H
i
:
Q
=
H
1
H
2
...
H
k
as returned by the
RQ
factorization routine gerqf.
Depending on the parameters
side
and
trans
, the routine can form one of the matrix products
Q
*
C
,
Q
T
*
C
,
C
*
Q
, or
C
*
Q
T
(overwriting the result over
C
).
Input Parameters
side
CHARACTER*1
.
Must be either
'L'
or
'R'
.
If
side
=
'L'
,
Q
or
Q
T
is applied to
C
from the left.
If
side
=
'R'
,
Q
or
Q
T
is applied to
C
from the right.
trans
CHARACTER*1
.
Must be either
'N'
or
'T'
.
If
trans
=
'N'
, the routine multiplies
C
by
Q
.
If
trans
=
'T'
, the routine multiplies
C
by
Q
T
.
m
INTEGER
.
The number of rows in the matrix
C
(
m
0
).
n
INTEGER
.
The number of columns in
C
(
n
0
).
k
INTEGER
.
The number of elementary reflectors whose product defines the matrix
Q
. Constraints:
0
k
m
, if
side
=
'L'
;
0
k
n
, if