p?laswp

Developer Reference for Intel® oneAPI Math Kernel Library for C

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ID 766684

Date 12/16/2022

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p?laswp

Performs a series of row interchanges on a general rectangular matrix.

Syntax

void pslaswp (char *direc , char *rowcol , MKL_INT *n , float *a , MKL_INT *ia , MKL_INT *ja , MKL_INT *desca , MKL_INT *k1 , MKL_INT *k2 , MKL_INT *ipiv );

void pdlaswp (char *direc , char *rowcol , MKL_INT *n , double *a , MKL_INT *ia , MKL_INT *ja , MKL_INT *desca , MKL_INT *k1 , MKL_INT *k2 , MKL_INT *ipiv );

void pclaswp (char *direc , char *rowcol , MKL_INT *n , MKL_Complex8 *a , MKL_INT *ia , MKL_INT *ja , MKL_INT *desca , MKL_INT *k1 , MKL_INT *k2 , MKL_INT *ipiv );

void pzlaswp (char *direc , char *rowcol , MKL_INT *n , MKL_Complex16 *a , MKL_INT *ia , MKL_INT *ja , MKL_INT *desca , MKL_INT *k1 , MKL_INT *k2 , MKL_INT *ipiv );

Include Files

mkl_scalapack.h

Description

The p?laswpfunction performs a series of row or column interchanges on the distributed matrix sub(A)=A(ia:ia+n-1, ja:ja+n-1). One interchange is initiated for each of rows or columns k1 through k2 of sub(A). This function assumes that the pivoting information has already been broadcast along the process row or column. Also note that this function will only work for k1-k2 being in the same mb (or nb) block. If you want to pivot a full matrix, use p?lapiv.

Input Parameters

direc

(global)

Specifies in which order the permutation is applied:

= 'F' - forward,

= 'B' - backward.

rowcol

(global)

Specifies if the rows or columns are permuted:

= 'R' - rows,

= 'C' - columns.

n

(global)

If rowcol='R', the length of the rows of the distributed matrix A(*, ja:ja+n-1) to be permuted;

If rowcol='C', the length of the columns of the distributed matrix A(ia:ia+n-1 , *) to be permuted;

a

(local)

Pointer into the local memory to an array of size lld_a * LOCc(n_a). On entry, this array contains the local pieces of the distributed matrix to which the row/columns interchanges will be applied.

ia

(global)

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

ja

(global)

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

desca

(global and local) array of size dlen_.

The array descriptor for the distributed matrix A.

k1

(global)

The first element of ipiv for which a row or column interchange will be done.

k2

(global)

The last element of ipiv for which a row or column interchange will be done.

ipiv

(local)

Array of size LOCr(m_a)+mb_a for row pivoting and LOCr(n_a)+nb_a for column pivoting. This array is tied to the matrix A, ipiv[k]=l implies rows (or columns) k+1 and l are to be interchanged, k = 0, 1, ..., size (ipiv) -1.

Output Parameters

A

(local)

On exit, the permuted distributed matrix.

Parent topic: ScaLAPACK Auxiliary Routines

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Developer Reference for Intel® oneAPI Math Kernel Library for C

p?laswp

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