SRC/claein.f(3)            Library Functions Manual            SRC/claein.f(3)

NAME
       SRC/claein.f

SYNOPSIS
   Functions/Subroutines
       subroutine claein (rightv, noinit, n, h, ldh, w, v, b, ldb, rwork,
           eps3, smlnum, info)
           CLAEIN computes a specified right or left eigenvector of an upper
           Hessenberg matrix by inverse iteration.

Function/Subroutine Documentation
   subroutine claein (logical rightv, logical noinit, integer n, complex,
       dimension( ldh, * ) h, integer ldh, complex w, complex, dimension( * )
       v, complex, dimension( ldb, * ) b, integer ldb, real, dimension( * )
       rwork, real eps3, real smlnum, integer info)
       CLAEIN computes a specified right or left eigenvector of an upper
       Hessenberg matrix by inverse iteration.

       Purpose:


           !>
           !> CLAEIN uses inverse iteration to find a right or left eigenvector
           !> corresponding to the eigenvalue W of a complex upper Hessenberg
           !> matrix H.
           !>

       Parameters
           RIGHTV

           !>          RIGHTV is LOGICAL
           !>          = .TRUE. : compute right eigenvector;
           !>          = .FALSE.: compute left eigenvector.
           !>

           NOINIT

           !>          NOINIT is LOGICAL
           !>          = .TRUE. : no initial vector supplied in V
           !>          = .FALSE.: initial vector supplied in V.
           !>

           N

           !>          N is INTEGER
           !>          The order of the matrix H.  N >= 0.
           !>

           H

           !>          H is COMPLEX array, dimension (LDH,N)
           !>          The upper Hessenberg matrix H.
           !>

           LDH

           !>          LDH is INTEGER
           !>          The leading dimension of the array H.  LDH >= max(1,N).
           !>

           W

           !>          W is COMPLEX
           !>          The eigenvalue of H whose corresponding right or left
           !>          eigenvector is to be computed.
           !>

           V

           !>          V is COMPLEX array, dimension (N)
           !>          On entry, if NOINIT = .FALSE., V must contain a starting
           !>          vector for inverse iteration; otherwise V need not be set.
           !>          On exit, V contains the computed eigenvector, normalized so
           !>          that the component of largest magnitude has magnitude 1; here
           !>          the magnitude of a complex number (x,y) is taken to be
           !>          |x| + |y|.
           !>

           B

           !>          B is COMPLEX array, dimension (LDB,N)
           !>

           LDB

           !>          LDB is INTEGER
           !>          The leading dimension of the array B.  LDB >= max(1,N).
           !>

           RWORK

           !>          RWORK is REAL array, dimension (N)
           !>

           EPS3

           !>          EPS3 is REAL
           !>          A small machine-dependent value which is used to perturb
           !>          close eigenvalues, and to replace zero pivots.
           !>

           SMLNUM

           !>          SMLNUM is REAL
           !>          A machine-dependent value close to the underflow threshold.
           !>

           INFO

           !>          INFO is INTEGER
           !>          = 0:  successful exit
           !>          = 1:  inverse iteration did not converge; V is set to the
           !>                last iterate.
           !>

       Author
           Univ. of Tennessee


           Univ. of California Berkeley


           Univ. of Colorado Denver


           NAG Ltd.

       Definition at line 147 of file claein.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.

LAPACK                          Version 3.12.0                 SRC/claein.f(3)