Developer Reference

  • 2020.2
  • 07/15/2020
  • Public Content
Contents

p?heevx

Computes selected eigenvalues and, optionally, eigenvectors of a Hermitian matrix.

Syntax

call pcheevx
(
jobz
,
range
,
uplo
,
n
,
a
,
ia
,
ja
,
desca
,
vl
,
vu
,
il
,
iu
,
abstol
,
m
,
nz
,
w
,
orfac
,
z
,
iz
,
jz
,
descz
,
work
,
lwork
,
rwork
,
lrwork
,
iwork
,
liwork
,
ifail
,
iclustr
,
gap
,
info
)
call pzheevx
(
jobz
,
range
,
uplo
,
n
,
a
,
ia
,
ja
,
desca
,
vl
,
vu
,
il
,
iu
,
abstol
,
m
,
nz
,
w
,
orfac
,
z
,
iz
,
jz
,
descz
,
work
,
lwork
,
rwork
,
lrwork
,
iwork
,
liwork
,
ifail
,
iclustr
,
gap
,
info
)
Include Files
Description
The
p?heevx
routine
computes selected eigenvalues and, optionally, eigenvectors of a complex Hermitian matrix
A
by calling the recommended sequence of ScaLAPACK
routines
. Eigenvalues and eigenvectors can be selected by specifying either a range of values or a range of indices for the desired eigenvalues.
Optimization Notice
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
This notice covers the following instruction sets: SSE2, SSE4.2, AVX2, AVX-512.
Input Parameters
np
= the number of rows local to a given process.
nq
= the number of columns local to a given process.
jobz
(global)
CHARACTER*1
.
Must be
'N'
or
'V'
.
Specifies if it is necessary to compute the eigenvectors:
If
jobz
=
'N'
, then only eigenvalues are computed.
If
jobz
=
'V'
, then eigenvalues and eigenvectors are computed.
range
(global)
CHARACTER*1
.
Must be
'A'
,
'V'
, or
'I'
.
If
range
=
'A'
, all eigenvalues will be found.
If
range
=
'V'
, all eigenvalues in the half-open interval
[
vl
,
vu
]
will be found.
If
range
=
'I'
, the eigenvalues with indices
il
through
iu
will be found.
uplo
(global)
CHARACTER*1
.
Must be
'U'
or
'L'
.
Specifies whether the upper or lower triangular part of the Hermitian matrix
A
is stored:
If
uplo
=
'U'
,
a
stores the upper triangular part of
A
.
If
uplo
=
'L'
,
a
stores the lower triangular part of
A
.
n
(global)
INTEGER
.
The number of rows and columns of the matrix
A
(
n