p?lase2

Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

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ID 766686

Date 12/16/2022

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p?lase2

Initializes an m-by-n distributed matrix.

Syntax

call pslase2 (uplo, m, n, alpha, beta, a, ia, ja, desca )

call pdlase2 (uplo, m, n, alpha, beta, a, ia, ja, desca )

call pclase2 (uplo, m, n, alpha, beta, a, ia, ja, desca )

call pzlase2 (uplo, m, n, alpha, beta, a, ia, ja, desca )

Description

p?lase2 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 off-diagonals. p?lase2 requires that only the dimension of the matrix operand is distributed.

Input Parameters

uplo

(global)

CHARACTER.

Specifies the part of the distributed matrix sub( A ) to be set:

= 'U': Upper triangular part is set; the strictly lower triangular part of sub( A ) is not changed;

= 'L': Lower triangular part is set; 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 to be operated on i.e the number of rows of the distributed submatrix sub( A ). m >= 0.

n

(global)

INTEGER.

The number of columns to be operated on i.e the number of columns of the distributed submatrix sub( A ). n >= 0.

alpha

(global)

REAL for pslase2

DOUBLE PRECISION for pdlase2

COMPLEX for pclase2

DOUBLE COMPLEX for pzlase2

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

beta

(global)

REAL for pslase2

DOUBLE PRECISION for pdlase2

COMPLEX for pclase2

DOUBLE COMPLEX for pzlase2

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

ia

(global)

INTEGER.

The row index in the global array a indicating the first row of sub( A ).

ja

(global)

INTEGER.

The column index in the global array a indicating the first column of sub( A ).

desca

(global and local)

INTEGER.

Array of size dlen_.

The array descriptor for the distributed matrix A.

Output Parameters

(local)

REAL for pslase2

DOUBLE PRECISION for pdlase2

COMPLEX for pclase2

DOUBLE COMPLEX for pzlase2

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 submatrix 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).

Parent topic: ScaLAPACK Auxiliary Routines

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Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

p?lase2