Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

ID 766686
Date 12/16/2022
Public

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Document Table of Contents

?dot

Computes a vector-vector dot product.

Syntax

res = sdot(n, x, incx, y, incy)

res = ddot(n, x, incx, y, incy)

res = dot(x, y)

Include Files
  • mkl.fi, blas.f90
Description

The ?dot routines perform a vector-vector reduction operation defined as


Equation

where xi and yi are elements of vectors x and y.

Input Parameters
n

INTEGER. Specifies the number of elements in vectors x and y.

x

REAL for sdot

DOUBLE PRECISION for ddot

Array, size at least (1+(n-1)*abs(incx)).

incx

INTEGER. Specifies the increment for the elements of x.

y

REAL for sdot

DOUBLE PRECISION for ddot

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

incy

INTEGER. Specifies the increment for the elements of y.

Output Parameters
res

REAL for sdot

DOUBLE PRECISION for ddot

Contains the result of the dot product of x and y, if n is positive. Otherwise, res contains 0.

BLAS 95 Interface Notes

Routines in Fortran 95 interface have fewer arguments in the calling sequence than their FORTRAN 77 counterparts. For general conventions applied to skip redundant or reconstructible arguments, see BLAS 95 Interface Conventions.

Specific details for the routine dot interface are the following:

x

Holds the vector with the number of elements n.

y

Holds the vector with the number of elements n.