p?dot

Developer Reference for Intel® oneAPI Math Kernel Library for C

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ID 766684

Date 11/07/2023

Version

Public

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p?dot

Computes the dot product of two distributed real vectors.

Syntax

void psdot (const MKL_INT *n , float *dot , 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 );

void pddot (const MKL_INT *n , double *dot , 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 );

Include Files

mkl_pblas.h

Description

The ?dot functions compute the dot product dot of two distributed real vectors defined as

dot  = sub(x)'*sub(y)

where sub(x) and sub(y) are n-element distributed vectors.

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

n

(global) The length of distributed vectors, n≥0.

x

(local)

Array, size (jx-1)*m_x + ix+(n-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 (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.

Output Parameters

dot

(local)

Dot product of sub(x) and sub(y) only in their scope.

Parent topic: PBLAS Level 1 Routines

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Developer Reference for Intel® oneAPI Math Kernel Library for C

p?dot

Syntax

Include Files

Description

Input Parameters

Output Parameters