Developer Reference

  • 098
  • 03/30/2020
  • Public Content
Contents

p?nrm2

Computes the Euclidean norm of a distributed vector.

Syntax

call psnrm2
(
n
,
norm2
,
x
,
ix
,
jx
,
descx
,
incx
)
call pdnrm2
(
n
,
norm2
,
x
,
ix
,
jx
,
descx
,
incx
)
call pscnrm2
(
n
,
norm2
,
x
,
ix
,
jx
,
descx
,
incx
)
call pdznrm2
(
n
,
norm2
,
x
,
ix
,
jx
,
descx
,
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)
INTEGER
.
The length of distributed vector
sub(
x
)
,
n
0.
x
(local)
REAL
for
psnrm2
DOUBLE PRECISION
for
pdnrm2
COMPLEX
for
pscnrm2
DOUBLE COMPLEX
for
pdznrm2
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.
Output Parameters
norm2
(local)
REAL
for
psnrm2
and
pscnrm2
.
DOUBLE PRECISION
for
pdnrm2
and
pdznrm2
Contains the Euclidean norm of a distributed vector only in its scope.

Product and Performance Information

1

Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.

Notice revision #20110804