Developer Reference

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

?syconv

Converts a symmetric matrix given by a triangular matrix factorization into two matrices and vice versa.

Syntax

call ssyconv
(
uplo
,
way
,
n
,
a
,
lda
,
ipiv
,
e
,
info
)
call dsyconv
(
uplo
,
way
,
n
,
a
,
lda
,
ipiv
,
e
,
info
)
call csyconv
(
uplo
,
way
,
n
,
a
,
lda
,
ipiv
,
e
,
info
)
call zsyconv
(
uplo
,
way
,
n
,
a
,
lda
,
ipiv
,
e
,
info
)
call syconv
(
a
[
,
uplo
]
[
,
way
]
[
,
ipiv
]
[
,
info
]
[
,
e
]
)
Include Files
  • mkl.fi
    ,
    lapack.f90
Description
The routine converts matrix
A
, which results from a triangular matrix factorization, into matrices
L
and
D
and vice versa. The routine returns non-diagonalized elements of
D
and applies or reverses permutation done with the triangular matrix factorization.
Input Parameters
uplo
CHARACTER*1
.
Must be
'U'
or
'L'
.
Indicates whether the details of the factorization are stored as an upper or lower triangular matrix:
If
uplo
=
'U'
: the upper triangular,
A
=
U*D*U
T
.
If
uplo
=
'L'
: the lower triangular,
A
=
L*D*L
T
.
way
CHARACTER*1
.
Must be
'C'
or
'R'
.
n
INTEGER
.
The order of matrix
A
;
n
0.
a
REAL
for
ssyconv
DOUBLE PRECISION
for
dsyconv
COMPLEX
for
csyconv
DOUBLE COMPLEX
for
zsyconv
Array of size
lda
by
n
.
The block diagonal matrix
D
and the multipliers used to obtain the factor
U
or
L
as computed by
?sytrf
.
lda
INTEGER
.
The leading dimension of
a
;
lda
max(1,
n
)
.
ipiv
INTEGER
.
Array, size at least
max(1,
n
)
.
Details of the interchanges and the block structure of
D
, as returned by
?sytrf
.
Output Parameters
<