Developer Reference for Intel® oneAPI Math Kernel Library for C

ID 766684
Date 11/07/2023
Public

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Document Table of Contents

p?ger

Performs a rank-1 update of a distributed general matrix.

Syntax

void psger (const MKL_INT *m , const MKL_INT *n , const float *alpha , const float *x , const MKL_INT *ix , const MKL_INT *jx , const MKL_INT *descx , const MKL_INT *incx , const float *y , const MKL_INT *iy , const MKL_INT *jy , const MKL_INT *descy , const MKL_INT *incy , float *a , const MKL_INT *ia , const MKL_INT *ja , const MKL_INT *desca );

void pdger (const MKL_INT *m , const MKL_INT *n , const double *alpha , const double *x , const MKL_INT *ix , const MKL_INT *jx , const MKL_INT *descx , const MKL_INT *incx , const double *y , const MKL_INT *iy , const MKL_INT *jy , const MKL_INT *descy , const MKL_INT *incy , double *a , const MKL_INT *ia , const MKL_INT *ja , const MKL_INT *desca );

Include Files

  • mkl_pblas.h

Description

The p?ger routines perform a distributed matrix-vector operation defined as

sub(A) := alpha*sub(x)*sub(y)' + sub(A),

where:

alpha is a scalar,

sub(A) is a m-by-n distributed general matrix, sub(A)=A(ia:ia+m-1, ja:ja+n-1),

sub(x) is an m-element distributed vector, sub(y) is an n-element distributed vector,

sub(x) denotes X(ix, jx:jx+m-1) if incx = m_x, and X(ix: ix+m-1, jx) if incx = 1,

sub(y) denotes Y(iy, jy:jy+n-1) if incy = m_y, and Y(iy: iy+n-1, jy) if incy = 1.

Input Parameters

m

(global) Specifies the number of rows of the distributed matrix sub(A), m0.

n

(global) Specifies the number of columns of the distributed matrix sub(A), n0.

alpha

(global)

Specifies the scalar alpha.

x

(local)

Array, size at least (jx-1)*m_x + ix+(m-1)*abs(incx)).

This array contains the entries of the distributed vector sub(x).

ix, jx

(global) The row and column indices in the distributed matrix X indicating the first row and the first column of the submatrix sub(x), respectively.

descx

(global and local) array of dimension 9. The array descriptor of the distributed matrix X.

incx

(global) Specifies the increment for the elements of sub(x). Only two values are supported, namely 1 and m_x. incx must not be zero.

y

(local)

Array, size at least (jy-1)*m_y + iy+(n-1)*abs(incy)).

This array contains the entries of the distributed vector sub(y).

iy, jy

(global) The row and column indices in the distributed matrix Y indicating the first row and the first column of the submatrix sub(y), respectively.

descy

(global and local) array of dimension 9. The array descriptor of the distributed matrix Y.

incy

(global) Specifies the increment for the elements of sub(y). Only two values are supported, namely 1 and m_y. incy must not be zero.

a

(local)

Array, size (lld_a, LOCq(ja+n-1)).

Before entry this array contains the local pieces of the distributed matrix sub(A).

ia, ja

(global) The row and column indices in the distributed matrix A indicating the first row and the first column of the submatrix sub(A), respectively.

desca

(global and local) array of dimension 9. The array descriptor of the distributed matrix A.

Output Parameters

a

Overwritten by the updated distributed matrix sub(A).