Developer Reference for Intel® oneAPI Math Kernel Library - C

Developer Reference

  • 0.9
  • 09/09/2020
  • 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

Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.

Notice revision #20110804