Developer Reference

  • 2021.1
  • 12/04/2020
  • Public Content
Contents

?unmlq

Multiplies a complex matrix by the unitary matrix Q of the LQ factorization formed by
?gelqf
.

Syntax

lapack_int
LAPACKE_cunmlq
(
int
matrix_layout
,
char
side
,
char
trans
,
lapack_int
m
,
lapack_int
n
,
lapack_int
k
,
const
lapack_complex_float
*
a
,
lapack_int
lda
,
const
lapack_complex_float
*
tau
,
lapack_complex_float
*
c
,
lapack_int
ldc
);
lapack_int
LAPACKE_zunmlq
(
int
matrix_layout
,
char
side
,
char
trans
,
lapack_int
m
,
lapack_int
n
,
lapack_int
k
,
const
lapack_complex_double
*
a
,
lapack_int
lda
,
const
lapack_complex_double
*
tau
,
lapack_complex_double
*
c
,
lapack_int
ldc
);
Include Files
  • mkl.h
Description
The routine multiplies a real
m
-by-
n
matrix
C
by
Q
or
Q
H
, where
Q
is the unitary matrix
Q
of the
LQ
factorization formed by the routine gelqf.
Depending on the parameters
side
and
trans
, the routine can form one of the matrix products
Q*C
,
Q
H
*C
,
C*Q
, or
C*Q
H
(overwriting the result on
C
).
Input Parameters
matrix_layout
Specifies whether matrix storage layout is row major (
LAPACK_ROW_MAJOR
) or column major (
LAPACK_COL_MAJOR
).
side
Must be either
'L'
or
'R'
.
If
side
=
'L'
,
Q
or
Q
H
is applied to
C
from the left.
If
side
=
'R'
,
Q
or
Q
H
is applied to
C
from the right.
trans
Must be either
'N'
or
'C'
.
If
trans
=
'N'
, the routine multiplies
C
by
Q
.
If
trans
=
'C'
, the routine multiplies
C
by
Q
H
.
m
The number of rows in the matrix
C
(
m
0
).
n
The number of columns in
C
(
n
0
).
k
The number of elementary reflectors whose product defines the matrix
Q
. Constraints:
0
k
m
if
side
=
'L'
;
0
k
n
if
side
=
'R'
.
a
,
c
,
tau
Arrays:
a
and
tau
are arrays returned by
?gelqf
.
The size of
a
must be:
For
side
= 'L' and column major layout, max(1,
lda
*
m
).
For
side
= 'R' and column major layout, max(1,
lda
*
n
).
For row major layout regardless of
side
, max(1,
lda
*
k
).
The size of
tau
must be at least max(1,
k
).
c
(size max(1,
ldc
*
n
) for column major layout and max(1,
ldc
*
m
for row major layout)
contains the
m
-by-
n
matrix
C
.
lda
The leading dimension of
a
. For column major layout,
lda
max(1,
k
). For row major layout, if
side
= 'L',
lda
max(1,
m
), or, if
side
= 'R',
lda
max(1,
n
).
ldc
The leading dimension of
c
;
ldc
max(1,
m
)
for column major layout and max(1,
n
) for row major layout
.
Output Parameters
c
Overwritten by the product
Q*C
,
Q
H
*C
,
C*Q
, or
C*Q
H
(as specified by
side
and
trans
).
Return Values
This function returns a value
info
.
If
info
=0
, the execution is successful.
If
info
=
-i
, the
i
-th parameter had an illegal value.
Application Notes
The real counterpart of this routine is ormlq.

Product and Performance Information

1

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