Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

ID 766686
Date 11/07/2023
Public

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p?dotu

Computes the dot product of two distributed complex vectors.

Syntax

call pcdotu(n, dotu, x, ix, jx, descx, incx, y, iy, jy, descy, incy)

call pzdotu(n, dotu, x, ix, jx, descx, incx, y, iy, jy, descy, incy)

Include Files

  • mkl_pblas.h

Description

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

dotu  = 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, n0.

x

(local) COMPLEX for pcdotu

DOUBLE COMPLEX for pzdotu

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 pcdotu

DOUBLE COMPLEX for pzdotu

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

dotu

(local) COMPLEX for pcdotu

DOUBLE COMPLEX for pzdotu

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