Developer Reference

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

?geev

Computes the eigenvalues and left and right eigenvectors of a general matrix.

Syntax

call sgeev
(
jobvl
,
jobvr
,
n
,
a
,
lda
,
wr
,
wi
,
vl
,
ldvl
,
vr
,
ldvr
,
work
,
lwork
,
info
)
call dgeev
(
jobvl
,
jobvr
,
n
,
a
,
lda
,
wr
,
wi
,
vl
,
ldvl
,
vr
,
ldvr
,
work
,
lwork
,
info
)
call cgeev
(
jobvl
,
jobvr
,
n
,
a
,
lda
,
w
,
vl
,
ldvl
,
vr
,
ldvr
,
work
,
lwork
,
rwork
,
info
)
call zgeev
(
jobvl
,
jobvr
,
n
,
a
,
lda
,
w
,
vl
,
ldvl
,
vr
,
ldvr
,
work
,
lwork
,
rwork
,
info
)
call geev
(
a
,
wr
,
wi
[
,
vl
]
[
,
vr
]
[
,
info
]
)
call geev
(
a
,
w
[
,
vl
]
[
,
vr
]
[
,
info
]
)
Include Files
  • mkl.fi
    ,
    lapack.f90
Description
The routine computes for an
n
-by-
n
real/complex nonsymmetric matrix
A
, the eigenvalues and, optionally, the left and/or right eigenvectors. The right eigenvector
v
of
A
satisfies
A
*
v
=
λ
*
v
where
λ
is its eigenvalue.
The left eigenvector
u
of
A
satisfies
u
H
*
A
=
λ
*
u
H
where
u
H
denotes the conjugate transpose of
u
. The computed eigenvectors are normalized to have Euclidean norm equal to 1 and largest component real.
Input Parameters
jobvl
CHARACTER*1
.
Must be
'N'
or
'V'
.
If
jobvl
=
'N'
, then left eigenvectors of
A
are not computed.
If
jobvl
=
'V'
, then left eigenvectors of
A
are computed.
jobvr
CHARACTER*1
.
Must be
'N'
or
'V'
.
If
jobvr
=
'N'
, then right eigenvectors of
A
are not computed.
If