Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

ID 766686
Date 6/24/2024
Public

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p?laset

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

Syntax

call pslaset(uplo, m, n, alpha, beta, a, ia, ja, desca)

call pdlaset(uplo, m, n, alpha, beta, a, ia, ja, desca)

call pclaset(uplo, m, n, alpha, beta, a, ia, ja, desca)

call pzlaset(uplo, m, n, alpha, beta, a, ia, ja, desca)

Description

The p?lasetroutine 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) CHARACTER.

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) INTEGER.

The number of rows in the distributed matrix sub(A). (m0).

n

(global) INTEGER.

The number of columns in the distributed matrix sub(A). (n0).

alpha

(global).

REAL for pslaset

DOUBLE PRECISION for pdlaset

COMPLEX for pclaset

COMPLEX*16 for pzlaset.

The constant to which the offdiagonal elements are to be set.

beta

(global).

REAL for pslaset

DOUBLE PRECISION for pdlaset

COMPLEX for pclaset

COMPLEX*16 for pzlaset.

The constant to which the diagonal elements are to be set.

Output Parameters

a

(local).

REAL for pslaset

DOUBLE PRECISION for pdlaset

COMPLEX for pclaset

COMPLEX*16 for pzlaset.

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≤ij-1, 1≤jn,

if uplo = 'L', A(ia+i-1, ja+j-1) = alpha, j+1≤im, 1≤jn,

otherwise, A(ia+i-1, ja+j-1) = alpha, 1≤im, 1≤jn, ia+ija+j, and, for all uplo, A(ia+i-1, ja+i-1) = beta, 1≤i≤min(m,n).

ia, ja

(global) INTEGER.

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)INTEGER.

Array of size dlen_. The array descriptor for the distributed matrix A.

See Also