Developer Reference

Contents

p?nrm2

Computes the Euclidean norm of a distributed vector.

Syntax

void psnrm2
(
const MKL_INT
*n
,
float
*norm2
,
const float
*x
,
const MKL_INT
*ix
,
const MKL_INT
*jx
,
const MKL_INT
*descx
,
const MKL_INT
*incx
);
void pdnrm2
(
const MKL_INT
*n
,
double
*norm2
,
const double
*x
,
const MKL_INT
*ix
,
const MKL_INT
*jx
,
const MKL_INT
*descx
,
const MKL_INT
*incx
);
void pscnrm2
(
const MKL_INT
*n
,
float
*norm2
,
const MKL_Complex8
*x
,
const MKL_INT
*ix
,
const MKL_INT
*jx
,
const MKL_INT
*descx
,
const MKL_INT
*incx
);
void pdznrm2
(
const MKL_INT
*n
,
double
*norm2
,
const MKL_Complex16
*x
,
const MKL_INT
*ix
,
const MKL_INT
*jx
,
const MKL_INT
*descx
,
const MKL_INT
*incx
);
Include Files
  • mkl_pblas.h
Description
The
p?nrm2
functions compute the Euclidean norm of a distributed vector
sub(
x
)
,
where
sub(
x
)
is an
n
-element distributed vector.
sub(
x
)
denotes
X
(
ix
,
jx
:
jx
+
n
-1)
if
incx
=
m_x
, and
X
(
ix
:
ix
+
n
-1,
jx
)
if
incx
= 1
.
Input Parameters
n
(global) The length of distributed vector
sub(
x
)
,
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.
Output Parameters
norm2
(local) and
pscnrm2
.
Contains the Euclidean norm of a distributed vector only in its scope.

Product and Performance Information

1

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