Developer Reference

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

?laref

Applies Householder reflectors to matrices on their rows or columns.

Syntax

call slaref
(
type
,
a
,
lda
,
wantz
,
z
,
ldz
,
block
,
irow1
,
icol1
,
istart
,
istop
,
itmp1
,
itmp2
,
liloz
,
lihiz
,
vecs
,
v2
,
v3
,
t1
,
t2
,
t3
)
call dlaref
(
type
,
a
,
lda
,
wantz
,
z
,
ldz
,
block
,
irow1
,
icol1
,
istart
,
istop
,
itmp1
,
itmp2
,
liloz
,
lihiz
,
vecs
,
v2
,
v3
,
t1
,
t2
,
t3
)
call claref
(
type
,
a
,
lda
,
wantz
,
z
,
ldz
,
block
,
irow1
,
icol1
,
istart
,
istop
,
itmp1
,
itmp2
,
liloz
,
lihiz
,
vecs
,
v2
,
v3
,
t1
,
t2
,
t3
)
call zlaref
(
type
,
a
,
lda
,
wantz
,
z
,
ldz
,
block
,
irow1
,
icol1
,
istart
,
istop
,
itmp1
,
itmp2
,
liloz
,
lihiz
,
vecs
,
v2
,
v3
,
t1
,
t2
,
t3
)
Description
?laref
applies one or several Householder reflectors of size 3 to one or two matrices (if column is specified) on either their rows or columns.
Input Parameters
type
(local)
CHARACTER*1.
If 'R': Apply reflectors to the rows of the matrix (apply from left)
Otherwise: Apply reflectors to the columns of the matrix
Unchanged on exit.
a
(local)
REAL
for
slaref
DOUBLE PRECISION
for
dlaref
COMPLEX
for
claref
DOUBLE COMPLEX
for
zlaref
Array,
(
lld_a
,
LOCc
(
ja
+
n
-1))
On entry, the matrix to receive the reflections.
lda
(local)
INTEGER.
On entry, the leading dimension of
a
.
Unchanged on exit.
wantz
(local)
LOGICAL.
If
.TRUE.
, then apply any column reflections to
z
as well.
If
.FALSE.
, then do no additional work on
z
.
z
(local)
REAL
for
slaref
DOUBLE PRECISION
for
dlaref
COMPLEX
for
claref
DOUBLE COMPLEX
for
zlaref
Array,
(
ldz
,
ncols
)
, where the value
ncols
depends on other