p?lase2

Developer Reference for Intel® oneAPI Math Kernel Library for C

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ID 766684

Date 3/31/2023

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p?lase2

Initializes an m-by-n distributed matrix.

Syntax

void pslase2 (const char* uplo, const MKL_INT* m, const MKL_INT* n, const float* alpha, const float* beta, float* a, const MKL_INT* ia, const MKL_INT* ja, const MKL_INT* desca);

void pdlase2 (const char* uplo, const MKL_INT* m, const MKL_INT* n, const double* alpha, const double* beta, double* a, const MKL_INT* ia, const MKL_INT* ja, const MKL_INT* desca);

void pclase2 (const char* uplo, const MKL_INT* m, const MKL_INT* n, const MKL_Complex8* alpha, const MKL_Complex8* beta, MKL_Complex8* a, const MKL_INT* ia, const MKL_INT* ja, const MKL_INT* desca);

void pzlase2 (const char* uplo, const MKL_INT* m, const MKL_INT* n, const MKL_Complex16* alpha, const MKL_Complex16* beta, MKL_Complex16* a, const MKL_INT* ia, const MKL_INT* ja, const MKL_INT* desca);

Include Files

mkl_scalapack.h

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)

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)

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

n

(global)

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

alpha

(global)

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

beta

(global)

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

ia

(global)

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

ja

(global)

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

desca

(global and local)

Array of size dlen_.

The array descriptor for the distributed matrix A.

Output Parameters

(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 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 C

p?lase2