p?lase2

Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

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ID 766686

Date 4/28/2026

Version

Public

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 )

Include Files

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

a

(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 ) .

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Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

p?lase2

Syntax

Include Files

Description

Input Parameters

Output Parameters