zhpev(l) [redhat man page]

ZHPEV(l)								 )								  ZHPEV(l)

NAME

       ZHPEV - compute all the eigenvalues and, optionally, eigenvectors of a complex Hermitian matrix in packed storage

SYNOPSIS

       SUBROUTINE ZHPEV( JOBZ, UPLO, N, AP, W, Z, LDZ, WORK, RWORK, INFO )

	   CHARACTER	 JOBZ, UPLO

	   INTEGER	 INFO, LDZ, N

	   DOUBLE	 PRECISION RWORK( * ), W( * )

	   COMPLEX*16	 AP( * ), WORK( * ), Z( LDZ, * )

PURPOSE

       ZHPEV computes all the eigenvalues and, optionally, eigenvectors of a complex Hermitian matrix in packed storage.

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.

       AP      (input/output) COMPLEX*16 array, dimension (N*(N+1)/2)
	       On  entry,  the	upper  or  lower triangle of the Hermitian matrix A, packed columnwise in a linear array.  The j-th column of A is
	       stored in the array AP as follows: if UPLO = 'U', AP(i + (j-1)*j/2) = A(i,j) for 1<=i<=j; if UPLO = 'L', AP(i + (j-1)*(2*n-j)/2)  =
	       A(i,j) for j<=i<=n.

	       On  exit,  AP  is  overwritten by values generated during the reduction to tridiagonal form.  If UPLO = 'U', the diagonal and first
	       superdiagonal of the tridiagonal matrix T overwrite the corresponding elements of A, and if UPLO = 'L', the diagonal and first sub-
	       diagonal of T overwrite the corresponding elements of A.

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

       Z       (output) COMPLEX*16 array, dimension (LDZ, N)
	       If  JOBZ  =  'V',  then if INFO = 0, Z contains the orthonormal eigenvectors of the matrix A, with the i-th column of Z holding the
	       eigenvector associated with W(i).  If JOBZ = 'N', then Z is not referenced.

       LDZ     (input) INTEGER
	       The leading dimension of the array Z.  LDZ >= 1, and if JOBZ = 'V', LDZ >= max(1,N).

       WORK    (workspace) COMPLEX*16 array, dimension (max(1, 2*N-1))

       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 							  ZHPEV(l)

zhpev.f(3)							      LAPACK								zhpev.f(3)

NAME

       zhpev.f -

SYNOPSIS

   Functions/Subroutines
       subroutine zhpev (JOBZ, UPLO, N, AP, W, Z, LDZ, WORK, RWORK, INFO)
	    ZHPEV computes the eigenvalues and, optionally, the left and/or right eigenvectors for OTHER matrices

Function/Subroutine Documentation
   subroutine zhpev (characterJOBZ, characterUPLO, integerN, complex*16, dimension( * )AP, double precision, dimension( * )W, complex*16,
       dimension( ldz, * )Z, integerLDZ, complex*16, dimension( * )WORK, double precision, dimension( * )RWORK, integerINFO)
	ZHPEV computes the eigenvalues and, optionally, the left and/or right eigenvectors for OTHER matrices

       Purpose:

	    ZHPEV computes all the eigenvalues and, optionally, eigenvectors of a
	    complex Hermitian matrix in packed storage.

       Parameters:
	   JOBZ

		     JOBZ is CHARACTER*1
		     = 'N':  Compute eigenvalues only;
		     = 'V':  Compute eigenvalues and eigenvectors.

	   UPLO

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

	   N

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

	   AP

		     AP is COMPLEX*16 array, dimension (N*(N+1)/2)
		     On entry, the upper or lower triangle of the Hermitian matrix
		     A, packed columnwise in a linear array.  The j-th column of A
		     is stored in the array AP as follows:
		     if UPLO = 'U', AP(i + (j-1)*j/2) = A(i,j) for 1<=i<=j;
		     if UPLO = 'L', AP(i + (j-1)*(2*n-j)/2) = A(i,j) for j<=i<=n.

		     On exit, AP is overwritten by values generated during the
		     reduction to tridiagonal form.  If UPLO = 'U', the diagonal
		     and first superdiagonal of the tridiagonal matrix T overwrite
		     the corresponding elements of A, and if UPLO = 'L', the
		     diagonal and first subdiagonal of T overwrite the
		     corresponding elements of A.

	   W

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

	   Z

		     Z is COMPLEX*16 array, dimension (LDZ, N)
		     If JOBZ = 'V', then if INFO = 0, Z contains the orthonormal
		     eigenvectors of the matrix A, with the i-th column of Z
		     holding the eigenvector associated with W(i).
		     If JOBZ = 'N', then Z is not referenced.

	   LDZ

		     LDZ is INTEGER
		     The leading dimension of the array Z.  LDZ >= 1, and if
		     JOBZ = 'V', LDZ >= max(1,N).

	   WORK

		     WORK is COMPLEX*16 array, dimension (max(1, 2*N-1))

	   RWORK

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

	   INFO

		     INFO is 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.

       Author:
	   Univ. of Tennessee

	   Univ. of California Berkeley

	   Univ. of Colorado Denver

	   NAG Ltd.

       Date:
	   November 2011

       Definition at line 138 of file zhpev.f.

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

Version 3.4.1							  Sun May 26 2013							zhpev.f(3)