Developer Reference

Contents

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.

Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.