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DSBEV(1)	      LAPACK driver routine (version 3.2)	      DSBEV(1)

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

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

	   CHARACTER	 JOBZ, UPLO

	   INTEGER	 INFO, KD, LDAB, LDZ, N

	   DOUBLE	 PRECISION AB( LDAB, * ), W( * ), WORK( * ), Z( LDZ, *
			 )

PURPOSE
       DSBEV  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) DOUBLE PRECISION 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 generÔÇÉ
	       ated  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 subdiagonal 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) DOUBLE PRECISION array, dimension (N)
	       If INFO = 0, the eigenvalues in ascending order.

       Z       (output) DOUBLE PRECISION 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) 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 driver routine (version 3November 2008			      DSBEV(1)
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