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

NAME
  SSBEV	- compute all the eigenvalues and, optionally, eigenvectors of a real
  symmetric band matrix	A

SYNOPSIS

  SUBROUTINE SSBEV( JOBZ, UPLO,	N, KD, AB, LDAB, W, Z, LDZ, WORK, INFO )

      CHARACTER	    JOBZ, UPLO

      INTEGER	    INFO, KD, LDAB, LDZ, N

      REAL	    AB(	LDAB, *	), W( *	), WORK( * ), Z( LDZ, *	)

PURPOSE
  SSBEV	computes all the eigenvalues and, optionally, eigenvectors of a	real
  symmetric band 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.

  KD	  (input) INTEGER
	  The number of	superdiagonals of the matrix A if UPLO = 'U', or the
	  number of subdiagonals if UPLO = 'L'.	 KD >= 0.

  AB	  (input/output) REAL array, dimension (LDAB, N)
	  On entry, the	upper or lower triangle	of the symmetric band matrix
	  A, stored in the first KD+1 rows of the array.  The j-th column of
	  A is stored in the j-th column of the	array AB as follows: if	UPLO
	  = 'U', AB(kd+1+i-j,j)	= A(i,j) for max(1,j-kd)<=i<=j;	if UPLO	=
	  'L', AB(1+i-j,j)    =	A(i,j) for j<=i<=min(n,j+kd).

	  On exit, AB is overwritten by	values generated during	the reduction
	  to tridiagonal form.	If UPLO	= 'U', the first superdiagonal and
	  the diagonal of the tridiagonal matrix T are returned	in rows	KD
	  and KD+1 of AB, and if UPLO =	'L', the diagonal and first subdiago-
	  nal of T are returned	in the first two rows of AB.

  LDAB	  (input) INTEGER
	  The leading dimension	of the array AB.  LDAB >= KD + 1.

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

  Z	  (output) REAL	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) 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.