claein(l) [redhat man page]

CLAEIN(l)								 )								 CLAEIN(l)

NAME

       CLAEIN - use inverse iteration to find a right or left eigenvector corresponding to the eigenvalue W of a complex upper Hessenberg matrix H

SYNOPSIS

       SUBROUTINE CLAEIN( RIGHTV, NOINIT, N, H, LDH, W, V, B, LDB, RWORK, EPS3, SMLNUM, INFO )

	   LOGICAL	  NOINIT, RIGHTV

	   INTEGER	  INFO, LDB, LDH, N

	   REAL 	  EPS3, SMLNUM

	   COMPLEX	  W

	   REAL 	  RWORK( * )

	   COMPLEX	  B( LDB, * ), H( LDH, * ), V( * )

PURPOSE

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

ARGUMENTS

       RIGHTV	(input) LOGICAL
		= .TRUE. : compute right eigenvector;
		= .FALSE.: compute left eigenvector.

       NOINIT	(input) LOGICAL
		= .TRUE. : no initial vector supplied in V
		= .FALSE.: initial vector supplied in V.

       N       (input) INTEGER
	       The order of the matrix H.  N >= 0.

       H       (input) COMPLEX array, dimension (LDH,N)
	       The upper Hessenberg matrix H.

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

       W       (input) COMPLEX
	       The eigenvalue of H whose corresponding right or left eigenvector is to be computed.

       V       (input/output) 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       (workspace) COMPLEX array, dimension (LDB,N)

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

       RWORK   (workspace) REAL array, dimension (N)

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

       SMLNUM  (input) REAL
	       A machine-dependent value close to the underflow threshold.

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

LAPACK version 3.0						   15 June 2000 							 CLAEIN(l)

zlaein.f(3)							      LAPACK							       zlaein.f(3)

NAME

       zlaein.f -

SYNOPSIS

   Functions/Subroutines
       subroutine zlaein (RIGHTV, NOINIT, N, H, LDH, W, V, B, LDB, RWORK, EPS3, SMLNUM, INFO)
	   ZLAEIN computes a specified right or left eigenvector of an upper Hessenberg matrix by inverse iteration.

Function/Subroutine Documentation
   subroutine zlaein (logicalRIGHTV, logicalNOINIT, integerN, complex*16, dimension( ldh, * )H, integerLDH, complex*16W, complex*16, dimension( *
       )V, complex*16, dimension( ldb, * )B, integerLDB, double precision, dimension( * )RWORK, double precisionEPS3, double precisionSMLNUM,
       integerINFO)
       ZLAEIN computes a specified right or left eigenvector of an upper Hessenberg matrix by inverse iteration.

       Purpose:

	    ZLAEIN 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*16 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*16
		     The eigenvalue of H whose corresponding right or left
		     eigenvector is to be computed.

	   V

		     V is COMPLEX*16 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*16 array, dimension (LDB,N)

	   LDB

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

	   RWORK

		     RWORK is DOUBLE PRECISION array, dimension (N)

	   EPS3

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

	   SMLNUM

		     SMLNUM is DOUBLE PRECISION
		     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.

       Date:
	   September 2012

       Definition at line 149 of file zlaein.f.

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

Version 3.4.2							  Tue Sep 25 2012						       zlaein.f(3)