Developer Reference for Intel® oneAPI Math Kernel Library - C

Developer Reference

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

?dttrsv

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

Syntax

void
sdttrsv
(
char
*uplo
,
char
*trans
,
MKL_INT
*n
,
MKL_INT
*nrhs
,
float
*dl
,
float
*d
,
float
*du
,
float
*b
,
MKL_INT
*ldb
,
MKL_INT
*info
);
void
ddttrsv
(
char
*uplo
,
char
*trans
,
MKL_INT
*n
,
MKL_INT
*nrhs
,
double
*dl
,
double
*d
,
double
*du
,
double
*b
,
MKL_INT
*ldb
,
MKL_INT
*info
);
void
cdttrsv
(
char
*uplo
,
char
*trans
,
MKL_INT
*n
,
MKL_INT
*nrhs
,
MKL_Complex8
*dl
,
MKL_Complex8
*d
,
MKL_Complex8
*du
,
MKL_Complex8
*b
,
MKL_INT
*ldb
,
MKL_INT
*info
);
void
zdttrsv
(
char
*uplo
,
char
*trans
,
MKL_INT
*n
,
MKL_INT
*nrhs
,
MKL_Complex16
*dl
,
MKL_Complex16
*d
,
MKL_Complex16
*du
,
MKL_Complex16
*b
,
MKL_INT
*ldb
,
MKL_INT
*info
);
Include Files
  • mkl_scalapack.h
Description
The
?dttrsv
function
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
Specifies whether to solve with
L
 or
U
.
trans
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
The order of the matrix
A
(
n
≥
 0)
.
nrhs
The number of right-hand sides, that is, the number of columns in the matrix
B
(
nrhs
≥
 0)
.
dl
,
d
,
du
,
b
The array
dl
 of size (
n
 - 1) contains the (
n
 - 1) multipliers that define the matrix
L
 from the
LU
 factorization of
A
.
The array
d
 of size
n
 contains
n
 diagonal elements of the upper triangular matrix
U
 from the
LU
 factorization of
A
.
The array
du
 of size (
n
 - 1) contains the (
n
 - 1) elements of the first super-diagonal of
U
.
On entry, the array
b
 of size
ldb
 *
nrhs
 contains the right-hand side of matrix
B
.
ldb
The leading dimension of the array
b
;
ldb
≥
 max(1,
n
)
.
Output Parameters
b
Overwritten by the solution matrix
X
.
info
If
info
=0
, the execution is successful.
If
info
 =
-i
, the
i
-th parameter had an illegal value.

Product and Performance Information

1

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