Contents

p?laset

Initializes the offdiagonal elements of a matrix to
alpha
and the diagonal elements to
beta
.

Syntax

Include Files
• mkl_scalapack.h
Description
The
p?laset
function
initializes an
m
-by-
n
distributed matrix sub(
A
) denoting
A
(
ia
:
ia
+
m
-1,
ja
:
ja
+
n
-1) to
beta
on the diagonal and
alpha
on the offdiagonals.
Input Parameters
uplo
(global)
Specifies the part of the distributed matrix sub(
A
) to be set:
if
uplo
=
'U'
: upper triangular part; the strictly lower triangular part of sub(
A
) is not changed;
if
uplo
=
'L'
: lower triangular part; the strictly upper triangular part of sub(
A
) is not changed.
Otherwise: all of the matrix sub(
A
) is set.
m
(global)
The number of rows in the distributed matrix sub(
A
).
(
m
0)
.
n
(global)
The number of columns in the distributed matrix sub(
A
).
(
n
0)
.
alpha
(global).
The constant to which the offdiagonal elements are to be set.
beta
(global).
The constant to which the diagonal elements are to be set.
Output Parameters
a
(local).
Pointer into the local memory to an array of size
lld_a
*
LOCc
(
ja
+
n
-1)
.
This array contains the local pieces of the distributed matrix sub(
A
) to be set. On exit, the leading
m
-by-
n
matrix sub(
A
) is set as follows:
if
uplo
=
'U'
,
A
(
ia
+
i
-1,
ja
+
j
-1) =
alpha
, 1≤
i
j
-1
, 1≤
j
n
,
if
uplo
=
'L'
,
A
(
ia
+
i
-1,
ja
+
j
-1) =
alpha
,
j
+1≤
i
m
, 1≤
j
n
,
otherwise,
A
(
ia
+
i
-1,
ja
+
j
-1) =
alpha
, 1≤
i
m
, 1≤
j
n
,
ia
+
i
ja
+
j
, and, for all
uplo
,
A
(
ia
+
i
-1,
ja
+
i
-1) =
beta
, 1≤
i
≤min(
m
,
n
).
ia
,
ja
(global)
The column and row indices in the distributed matrix
A
indicating the first row and column of the matrix sub(
A
), respectively.
desca
(global and local)
Array of size
dlen_
. The array descriptor for the distributed matrix
A
.

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