Developer Reference for Intel® oneAPI Math Kernel Library - C

Developer Reference

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

p?laswp

Performs a series of row interchanges on a general rectangular matrix.

Syntax

void
pslaswp
(
char
*direc
,
char
*rowcol
,
MKL_INT
*n
,
float
*a
,
MKL_INT
*ia
,
MKL_INT
*ja
,
MKL_INT
*desca
,
MKL_INT
*k1
,
MKL_INT
*k2
,
MKL_INT
*ipiv
);
void
pdlaswp
(
char
*direc
,
char
*rowcol
,
MKL_INT
*n
,
double
*a
,
MKL_INT
*ia
,
MKL_INT
*ja
,
MKL_INT
*desca
,
MKL_INT
*k1
,
MKL_INT
*k2
,
MKL_INT
*ipiv
);
void
pclaswp
(
char
*direc
,
char
*rowcol
,
MKL_INT
*n
,
MKL_Complex8
*a
,
MKL_INT
*ia
,
MKL_INT
*ja
,
MKL_INT
*desca
,
MKL_INT
*k1
,
MKL_INT
*k2
,
MKL_INT
*ipiv
);
void
pzlaswp
(
char
*direc
,
char
*rowcol
,
MKL_INT
*n
,
MKL_Complex16
*a
,
MKL_INT
*ia
,
MKL_INT
*ja
,
MKL_INT
*desca
,
MKL_INT
*k1
,
MKL_INT
*k2
,
MKL_INT
*ipiv
);
Include Files
  • mkl_scalapack.h
Description
The
p?laswp
function
performs a series of row or column interchanges on the distributed matrix
sub(
A
)=
A
(
ia
:
ia
+
n
-1,
ja
:
ja
+
n
-1)
. One interchange is initiated for each of rows or columns
k1
 through
k2
 of sub(
A
). This
function
assumes that the pivoting information has already been broadcast along the process row or column. Also note that this
function
will only work for
k1-k2
 being in the same
mb
 (or
nb
) block. If you want to pivot a full matrix, use
p?lapiv
.
Input Parameters
direc
(global)
Specifies in which order the permutation is applied:
=
'F'
 - forward,
=
'B'
 - backward.
rowcol
(global)
Specifies if the rows or columns are permuted:
=
'R'
 - rows,
=
'C'
 - columns.
n
(global)
If
rowcol
=
'R'
, the length of the rows of the distributed matrix
A
(*,
ja
:
ja
+
n
-1)
 to be permuted;
If
rowcol
=
'C'
, the length of the columns of the distributed matrix
A
(
ia
:
ia
+
n
-1 , *)
 to be permuted;
a
(local)
Pointer into the local memory to an array of size
lld_a
 *
LOCc
(
n_a
)
. On entry, this array contains the local pieces of the distributed matrix to which the row/columns interchanges will be applied.
ia
(global)
The row index in the global matrix
A
 indicating the first row of sub(
A
).
ja
(global)
The column index in the global matrix
A
 indicating the first column of sub(
A
).
desca
(global and local) array of size
dlen_
.
The array descriptor for the distributed matrix
A
.
k1
(global)
The first element of
ipiv
 for which a row or column interchange will be done.
k2
(global)
The last element of
ipiv
 for which a row or column interchange will be done.
ipiv
(local)
Array of size
LOCr
(
m_a
)+
mb_a
 for row pivoting and
LOCr
(
n_a
)+
nb_a
 for column pivoting. This array is tied to the matrix
A
,
ipiv
[
k
]
=
l
 implies rows (or columns)
k
+1
 and
l
 are to be interchanged
,
k
 = 0, 1, ..., size (
ipiv
) -1
.
Output Parameters
A
(local)
On exit, the permuted distributed matrix.

Product and Performance Information

1

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