Developer Reference for Intel® oneAPI Math Kernel Library - C

Developer Reference

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

?dttrsb

Solves a system of linear equations with a diagonally dominant tridiagonal coefficient matrix using the LU factorization computed by
?dttrfb
.

Syntax

void
sdttrsb
(
const
char
*
trans
,
const
MKL_INT
*
n
,
const
MKL_INT
*
nrhs
,
const
float
*
dl
,
const
float
*
d
,
const
float
*
du
,
float
*
b
,
const
MKL_INT
*
ldb
,
MKL_INT
*
info
);
void
ddttrsb
(
const
char
*
trans
,
const
MKL_INT
*
n
,
const
MKL_INT
*
nrhs
,
const
double
*
dl
,
const
double
*
d
,
const
double
*
du
,
double
*
b
,
const
MKL_INT
*
ldb
,
MKL_INT
*
info
);
void
cdttrsb
(
const
char
*
trans
,
const
MKL_INT
*
n
,
const
MKL_INT
*
nrhs
,
const
MKL_Complex8
*
dl
,
const
MKL_Complex8
*
d
,
const
MKL_Complex8
*
du
,
MKL_Complex8
*
b
,
const
MKL_INT
*
ldb
,
MKL_INT
*
info
);
void
zdttrsb
(
const
char
*
trans
,
const
MKL_INT
*
n
,
const
MKL_INT
*
nrhs
,
const
MKL_Complex16
*
dl
,
const
MKL_Complex16
*
d
,
const
MKL_Complex16
*
du
,
MKL_Complex16
*
b
,
const
MKL_INT
*
ldb
,
MKL_INT
*
info
);
Include Files
  • mkl.h
Description
The
?dttrsb
 routine solves the following systems of linear equations with multiple right hand sides for
X
:
A
*
X
 =
B
if
trans
=
'N'
,
A
T
*
X
 =
B
if
trans
=
'T'
,
A
H
*
X
 =
B
if
trans
=
'C'
 (for complex matrices only).
Before calling this routine, call
?dttrfb
 to compute the factorization of
A
.
Input Parameters
trans
Must be
'N'
 or
'T'
 or
'C'
.
Indicates the form of the equations solved for
X
:
If
trans
 =
'N'
, then
A
*
X
 =
B
.
If
trans
 =
'T'
, then
A
T
*
X
 =
B
.
If
trans
 =
'C'
, then
A
H
*
X
 =
B
.
n
The order of
A
;
n
≥
 0.
nrhs
The number of right-hand sides, that is, the number of columns in
B
;
nrhs
≥
 0.
dl
,
d
,
du
Arrays:
dl
(
n
 -1)
,
d
(
n
)
,
du
(
n
 -1)
.
The array
dl
 contains the
(
n
 - 1)
 multipliers that define the matrices
L
1
,
L
2
 from the factorization of
A
.
The array
d
 contains the
n
 diagonal elements of the upper triangular matrix
U
 from the factorization of
A
.
The array
du
 contains the (
n
 - 1) elements of the superdiagonal of
U
.
b
Array of size max(1,
ldb
*
nrhs
). Contains the matrix
B
 whose columns are the right-hand sides for the systems of equations.
ldb
The leading dimension of
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.