Unix/Linux Go Back    


RedHat 9 (Linux i386) - man page for zheev (redhat section l)

Linux & Unix Commands - Search Man Pages
Man Page or Keyword Search:   man
Select Man Page Set:       apropos Keyword Search (sections above)


ZHEEV(l)					)					 ZHEEV(l)

NAME
       ZHEEV  -  compute  all  eigenvalues  and,  optionally, eigenvectors of a complex Hermitian
       matrix A

SYNOPSIS
       SUBROUTINE ZHEEV( JOBZ, UPLO, N, A, LDA, W, WORK, LWORK, RWORK, INFO )

	   CHARACTER	 JOBZ, UPLO

	   INTEGER	 INFO, LDA, LWORK, N

	   DOUBLE	 PRECISION RWORK( * ), W( * )

	   COMPLEX*16	 A( LDA, * ), WORK( * )

PURPOSE
       ZHEEV computes all eigenvalues and, optionally, eigenvectors of a complex Hermitian matrix
       A.

ARGUMENTS
       JOBZ    (input) CHARACTER*1
	       = 'N':  Compute eigenvalues only;
	       = 'V':  Compute eigenvalues and eigenvectors.

       UPLO    (input) CHARACTER*1
	       = 'U':  Upper triangle of A is stored;
	       = 'L':  Lower triangle of A is stored.

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

       A       (input/output) COMPLEX*16 array, dimension (LDA, N)
	       On  entry, the Hermitian matrix A.  If UPLO = 'U', the leading N-by-N upper trian-
	       gular part of A contains the upper triangular part of the matrix  A.   If  UPLO	=
	       'L',  the  leading N-by-N lower triangular part of A contains the lower triangular
	       part of the matrix A.  On exit, if JOBZ = 'V', then if INFO = 0,  A  contains  the
	       orthonormal  eigenvectors  of the matrix A.  If JOBZ = 'N', then on exit the lower
	       triangle (if UPLO='L') or the upper triangle (if UPLO='U')  of  A,  including  the
	       diagonal, is destroyed.

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

       W       (output) DOUBLE PRECISION array, dimension (N)
	       If INFO = 0, the eigenvalues in ascending order.

       WORK    (workspace/output) COMPLEX*16 array, dimension (LWORK)
	       On exit, if INFO = 0, WORK(1) returns the optimal LWORK.

       LWORK   (input) INTEGER
	       The  length  of	the  array WORK.  LWORK >= max(1,2*N-1).  For optimal efficiency,
	       LWORK >= (NB+1)*N, where NB is the blocksize for ZHETRD returned by ILAENV.

	       If LWORK = -1, then a workspace query is assumed; the routine only calculates  the
	       optimal	size of the WORK array, returns this value as the first entry of the WORK
	       array, and no error message related to LWORK is issued by XERBLA.

       RWORK   (workspace) DOUBLE PRECISION array, dimension (max(1, 3*N-2))

       INFO    (output) INTEGER
	       = 0:  successful exit
	       < 0:  if INFO = -i, the i-th argument had an illegal value
	       > 0:  if INFO = i, the algorithm failed to converge; i off-diagonal elements of an
	       intermediate tridiagonal form did not converge to zero.

LAPACK version 3.0			   15 June 2000 				 ZHEEV(l)
Unix & Linux Commands & Man Pages : ©2000 - 2018 Unix and Linux Forums


All times are GMT -4. The time now is 07:13 PM.