Developer Reference for Intel® oneAPI Math Kernel Library for C

ID 766684
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

void pslaset (char *uplo , MKL_INT *m , MKL_INT *n , float *alpha , float *beta , float *a , MKL_INT *ia , MKL_INT *ja , MKL_INT *desca );

void pdlaset (char *uplo , MKL_INT *m , MKL_INT *n , double *alpha , double *beta , double *a , MKL_INT *ia , MKL_INT *ja , MKL_INT *desca );

void pclaset (char *uplo , MKL_INT *m , MKL_INT *n , MKL_Complex8 *alpha , MKL_Complex8 *beta , MKL_Complex8 *a , MKL_INT *ia , MKL_INT *ja , MKL_INT *desca );

void pzlaset (char *uplo , MKL_INT *m , MKL_INT *n , MKL_Complex16 *alpha , MKL_Complex16 *beta , MKL_Complex16 *a , MKL_INT *ia , MKL_INT *ja , MKL_INT *desca );

Include Files

  • mkl_scalapack.h

Description

The p?lasetfunction 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.

See Also