Developer Reference

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

?gemlqt

Multiplies a general matrix by the orthogonal/unitary matrix
Q
of the LQ factorization formed by
?gelqt
.
call sgemlqt
(
side
,
trans
,
m
,
n
,
k
,
mb
,
v
,
ldv
,
t
,
ldt
,
c
,
ldc
,
work
,
info
)
call dgemlqt
(
side
,
trans
,
m
,
n
,
k
,
mb
,
v
,
ldv
,
t
,
ldt
,
c
,
ldc
,
work
,
info
)
call cgemlqt
(
side
,
trans
,
m
,
n
,
k
,
mb
,
v
,
ldv
,
t
,
ldt
,
c
,
ldc
,
work
,
info
)
call zgemlqt
(
side
,
trans
,
m
,
n
,
k
,
mb
,
v
,
ldv
,
t
,
ldt
,
c
,
ldc
,
work
,
info
)
Description
?gemlqt
overwrites the general real
m
-by-
n
matrix
C
with
side
= 'L'
side
= 'R'
trans
= 'N'
Q
*
C
C
*
Q
trans
= 'T'
Q
T
*
C
C
*
Q
T
trans
= 'C'
Q
H
*
C
C
*
Q
H
where
Q
is a real or complex orthogonal matrix defined as the product of
k
elementary reflectors:
Q
=
H
(
k
)
H
(
k
- 1) . . .
H
(1) =
I
-
V
T
V
T
for real flavors
or
Q
=
H
(
k
)
H
H
(
k
- 1)
H
. . .
H
(1)
H
=
I
-
V
T
V
H
for complex flavors
generated using the compact WY representation as returned by
?gelqt
.
Q
is of order
m
if
side
= 'L' and of order
n
if
side
= 'R'.
Input Parameters
side
CHARACTER*1
.
If
side
= 'L': apply op(
Q
) from the left;
if
side
= 'R': apply op(
Q
) from the right.
trans
CHARACTER*1
.
If