CHPEV(l)	     LAPACK driver routine (version 1.1)	     CHPEV(l)

NAME
  CHPEV	- compute all the eigenvalues and, optionally, eigenvectors of a com-
  plex Hermitian matrix	in packed storage

SYNOPSIS

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

      CHARACTER	    JOBZ, UPLO

      INTEGER	    INFO, LDZ, N

      REAL	    RWORK( * ),	W( * )

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

PURPOSE
  CHPEV	computes all the eigenvalues and, optionally, eigenvectors of a	com-
  plex 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 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 super-
	  diagonal of the tridiagonal matrix T overwrite the corresponding
	  elements of A, and if	UPLO = 'L', the	diagonal and first subdiago-
	  nal of T overwrite the corresponding elements	of A.

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

  Z	  (output) COMPLEX array, dimension (LDZ, N)
	  If JOBZ = 'V', then if INFO =	0, Z contains the orthonormal eigen-
	  vectors 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 array, dimension (max(1, 2*N-1))

  RWORK	  (workspace) REAL 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.