# zlaein.f(3) [debian man page]

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) ZLAEINFunction/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 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: November 2011 Definition at line 149 of file zlaein.f.AuthorGenerated automatically by Doxygen for LAPACK from the source code.Version 3.4.1Sun May 26 2013 zlaein.f(3)

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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.AuthorGenerated automatically by Doxygen for LAPACK from the source code.Version 3.4.2Tue Sep 25 2012 zlaein.f(3)