dgebak.f3
Usage
Functions/Subroutines
subroutine dgebak (job, side, n, ilo, ihi, scale, m, v, ldv, info)
DGEBAK
Function/Subroutine Documentation
subroutine dgebak (character job, character side, integer n, integer ilo, integer ihi, double precision, dimension( * ) scale, integer m, double precision, dimension( ldv, * ) v, integer ldv, integer info)
DGEBAK
Purpose:
!> !> DGEBAK forms the right or left eigenvectors of a real general matrix !> by backward transformation on the computed eigenvectors of the !> balanced matrix output by DGEBAL. !>
Parameters
JOB
!> JOB is CHARACTER*1 !> Specifies the type of backward transformation required: !> = 'N': do nothing, return immediately; !> = 'P': do backward transformation for permutation only; !> = 'S': do backward transformation for scaling only; !> = 'B': do backward transformations for both permutation and !> scaling. !> JOB must be the same as the argument JOB supplied to DGEBAL. !>
SIDE
!> SIDE is CHARACTER*1 !> = 'R': V contains right eigenvectors; !> = 'L': V contains left eigenvectors. !>
N
!> N is INTEGER !> The number of rows of the matrix V. N >= 0. !>
ILO
!> ILO is INTEGER !>
IHI
!> IHI is INTEGER !> The integers ILO and IHI determined by DGEBAL. !> 1 <= ILO <= IHI <= N, if N > 0; ILO=1 and IHI=0, if N=0. !>
SCALE
!> SCALE is DOUBLE PRECISION array, dimension (N) !> Details of the permutation and scaling factors, as returned !> by DGEBAL. !>
M
!> M is INTEGER !> The number of columns of the matrix V. M >= 0. !>
V
!> V is DOUBLE PRECISION array, dimension (LDV,M) !> On entry, the matrix of right or left eigenvectors to be !> transformed, as returned by DHSEIN or DTREVC. !> On exit, V is overwritten by the transformed eigenvectors. !>
LDV
!> LDV is INTEGER !> The leading dimension of the array V. LDV >= max(1,N). !>
INFO
!> INFO is INTEGER !> = 0: successful exit !> < 0: if INFO = -i, the i-th argument had an illegal value. !>
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Definition at line 128 of file dgebak.f.
Releases
4 releases since Debian 7 (Wheezy); the text changed 3 times.