Developer Reference

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

?dttrsv

Solves a general tridiagonal system of linear equations using the LU factorization computed by
?dttrf
.

Syntax

call sdttrsv
(
uplo
,
trans
,
n
,
nrhs
,
dl
,
d
,
du
,
b
,
ldb
,
info
)
call ddttrsv
(
uplo
,
trans
,
n
,
nrhs
,
dl
,
d
,
du
,
b
,
ldb
,
info
)
call cdttrsv
(
uplo
,
trans
,
n
,
nrhs
,
dl
,
d
,
du
,
b
,
ldb
,
info
)
call zdttrsv
(
uplo
,
trans
,
n
,
nrhs
,
dl
,
d
,
du
,
b
,
ldb
,
info
)
Description
The
?dttrsv
routine
solves one of the following systems of linear equations:
L*X
=
B
,
L
T
*X
=
B
, or
L
H
*X
=
B
,
U*X
=
B
,
U
T
*X
=
B
, or
U
H
*X
=
B
with factors of the tridiagonal matrix
A
from the
LU
factorization computed by
?dttrf
.
Input Parameters
uplo
CHARACTER*1
.
Specifies whether to solve with
L
or
U
.
trans
CHARACTER
.
Must be
'N'
or
'T'
or
'C'
.
Indicates the form of the equations:
If
trans
=
'N'
, then
A
*
X
=
B
is solved for
X
(no transpose).
If
trans
=
'T'
, then
A
T
*
X
=
B
is solved for
X
(transpose).
If
trans
=
'C'
, then
A
H
*
X
=
B
is solved for
X
(conjugate transpose).
n
INTEGER
.
The order of the matrix
A
(
n
0)
.
nrhs
INTEGER
.
The number of right-hand sides, that is, the number of columns in the matrix
B
(
nrhs
0)
.
dl
,
d
,