Developer Reference for Intel® oneAPI Math Kernel Library - C

Developer Reference

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

p?trsm

Solves a distributed matrix equation (one matrix operand is triangular).

Syntax

void pstrsm
(
const char
*side
,
const char
*uplo
,
const char
*transa
,
const char
*diag
,
const MKL_INT
*m
,
const MKL_INT
*n
,
const float
*alpha
,
const float
*a
,
const MKL_INT
*ia
,
const MKL_INT
*ja
,
const MKL_INT
*desca
,
float
*b
,
const MKL_INT
*ib
,
const MKL_INT
*jb
,
const MKL_INT
*descb
);
void pdtrsm
(
const char
*side
,
const char
*uplo
,
const char
*transa
,
const char
*diag
,
const MKL_INT
*m
,
const MKL_INT
*n
,
const double
*alpha
,
const double
*a
,
const MKL_INT
*ia
,
const MKL_INT
*ja
,
const MKL_INT
*desca
,
double
*b
,
const MKL_INT
*ib
,
const MKL_INT
*jb
,
const MKL_INT
*descb
);
void pctrsm
(
const char
*side
,
const char
*uplo
,
const char
*transa
,
const char
*diag
,
const MKL_INT
*m
,
const MKL_INT
*n
,
const MKL_Complex8
*alpha
,
const MKL_Complex8
*a
,
const MKL_INT
*ia
,
const MKL_INT
*ja
,
const MKL_INT
*desca
,
MKL_Complex8
*b
,
const MKL_INT
*ib
,
const MKL_INT
*jb
,
const MKL_INT
*descb
);
void pztrsm
(
const char
*side
,
const char
*uplo
,
const char
*transa
,
const char
*diag
,
const MKL_INT
*m
,
const MKL_INT
*n
,
const MKL_Complex16
*alpha
,
const MKL_Complex16
*a
,
const MKL_INT
*ia
,
const MKL_INT
*ja
,
const MKL_INT
*desca
,
MKL_Complex16
*b
,
const MKL_INT
*ib
,
const MKL_INT
*jb
,
const MKL_INT
*descb
);
Include Files
  • mkl_pblas.h
Description
The
p?trsm
 routines solve one of the following distributed matrix equations: 
op(sub(A))*X = alpha*sub(B),
or 
X*op(sub(A)) = alpha*sub(B),
where:
alpha
 is a scalar,
X
 and
sub(
B
)
 are
m
-by-
n
 distributed matrices,
sub(
B
)=
B
(
ib
:
ib
+
m
-1,
jb
:
jb
+
n
-1)
;
A
 is a unit, or non-unit, upper or lower triangular distributed matrix,
sub(
A
)=
A
(
ia
:
ia
+
m
-1,
ja
:
ja
+
m
-1)
, if
side
 = '
L
'
 or
'
l
'
, and
sub(
A
)=
A
(
ia
:
ia
+
n
-1,
ja
:
ja
+
n
-1)
, if
side
 = '
R
'
 or
'
r
'
;
op(sub(
A
))
 is one of
op(sub(
A
)) = sub(
A
)
, or
op(sub(
A
)) = sub(
A
)'
, or
op(sub(
A
)) = conjg(sub(
A
)')
.
The distributed matrix
sub(
B
)
 is overwritten by the solution matrix
X
.
Input Parameters
side
(global) Specifies whether
op(sub(
A
))
 appears on the left or right of
X
 in the equation:
if
side
 =
'L'
 or
'l'
, then
op(sub(
A
))*
X
 =
alpha
*sub(
B
)
;
if
side
 =
'R'
 or
'r'
, then
X
*op(sub(
A
)) =
alpha
*sub(
B
)
.
uplo
(global) Specifies whether the distributed matrix
sub(
A
)
 is upper or lower triangular:
if
uplo
 =
'U'
 or
'u'
, then the matrix is upper triangular;
if
uplo
 =
'L'
 or
'l'
, then the matrix is low triangular.
transa
(global) Specifies the form of
op(sub(
A
))
 used in the matrix equation:
if
transa
 = '
N
'
 or
'
n
'
, then
op(sub(
A
)) = sub(
A
)
;
if
transa
= '
T
'
 or
'
t
'
, then
op(sub(
A
)) = sub(
A
)'
;
if
transa
 = '
C
'
 or
'
c
'
, then
op(sub(
A
)) = conjg(sub(
A
)')
.
diag
(global) Specifies whether the matrix
sub(
A
)
 is unit triangular:
if
diag
 =
'U'
 or
'u'
 then the matrix is unit triangular;
if
diag
 =
'N'
 or
'n'
, then the matrix is not unit triangular.
m
(global) Specifies the number of rows of the distributed matrix
sub(
B
)
,
m
≥
 0.
n
(global) Specifies the number of columns of the distributed matrix
sub(
B
)
,
n
≥
 0.
alpha
(global)
Specifies the scalar
alpha
.
When
alpha
 is zero, then
a
 is not referenced and
b
 need not be set before entry.
a
(local)
Array, size
lld_a
 by
ka
, where
ka
 is at least
LOCq(1,
ja
+
m
-1)
 when
side
 =
'L'
 or
'l'
 and is at least
LOCq(1,
ja
+
n
-1)
 when
side
 =
'R'
 or
'r'
.
Before entry with
uplo
 =
'U'
 or
'u'
, this array contains the local entries corresponding to the entries of the upper triangular distributed matrix
sub(
A
)
, and the local entries corresponding to the entries of the strictly lower triangular part of the distributed matrix
sub(
A
)
 is not referenced.
Before entry with
uplo
 =
'L'
 or
'l'
, this array contains the local entries corresponding to the entries of the lower triangular distributed matrix
sub(
A
)
, and the local entries corresponding to the entries of the strictly upper triangular part of the distributed matrix
sub(
A
)
 is not referenced .
When
diag
 =
'U'
 or
'u'
, the local entries corresponding to the diagonal elements of the submatrix
sub(
A
)
 are not referenced either, but are assumed to be unity.
ia
,
ja
(global) The row and column indices in the distributed matrix
A
 indicating the first row and the first column of the submatrix
sub(
A
)
, respectively.
desca
(global and local) array of dimension 9. The array descriptor of the distributed matrix
A
.
b
(local)
Array, size (
lld_b
,
LOCq(1,
jb
+
n
-1)
).
Before entry, this array contains the local pieces of the distributed matrix
sub(
B
)
.
ib
,
jb
(global) The row and column indices in the distributed matrix
B
 indicating the first row and the first column of the submatrix
sub(
B
)
, respectively.
descb
(global and local) array of dimension 9. The array descriptor of the distributed matrix
B
.
Output Parameters
b
Overwritten by the solution distributed matrix
X
.

Product and Performance Information

1

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