p?dotc

Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

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ID 766686

Date 3/31/2023

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p?dotc

Computes the dot product of two distributed complex vectors, one of them is conjugated.

Syntax

call pcdotc(n, dotc, x, ix, jx, descx, incx, y, iy, jy, descy, incy)

call pzdotc(n, dotc, x, ix, jx, descx, incx, y, iy, jy, descy, incy)

Include Files

mkl_pblas.h

Description

The p?dotc functions compute the dot product dotc of two distributed vectors, with one vector conjugated:

dotc  = conjg(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) INTEGER. The length of distributed vectors, n≥0.

x

(local)COMPLEX for pcdotc

DOUBLE COMPLEX for pzdotc

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) INTEGER. 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) INTEGER array of dimension 9. The array descriptor of the distributed matrix X.

incx

(global) INTEGER. 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) COMPLEX for pcdotc

DOUBLE COMPLEX for pzdotc

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) INTEGER. 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) INTEGER array of dimension 9. The array descriptor of the distributed matrix Y.

incy

(global) INTEGER. 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

dotc

(local) COMPLEX for pcdotc

DOUBLE COMPLEX for pzdotc

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 Fortran

p?dotc