CXML
        	    
LAPACK version 3.0
claed0(3)

PURPOSE
  CLAED0 - the divide and conquer method, CLAED0 computes all eigenvalues of
  a symmetric tridiagonal matrix which is one diagonal block of those from
  reducing a dense or band Hermitian matrix and corresponding eigenvectors of
  the dense or band matrix

SYNTAX
  SUBROUTINE CLAED0( QSIZ, N, D, E, Q, LDQ, QSTORE, LDQS, RWORK, IWORK, INFO
		     )

      INTEGER	     INFO, LDQ, LDQS, N, QSIZ

      INTEGER	     IWORK( * )

      REAL	     D( * ), E( * ), RWORK( * )

      COMPLEX	     Q( LDQ, * ), QSTORE( LDQS, * )

DESCRIPTION
  Using the divide and conquer method, CLAED0 computes all eigenvalues of a
  symmetric tridiagonal matrix which is one diagonal block of those from
  reducing a dense or band Hermitian matrix and corresponding eigenvectors of
  the dense or band matrix.

ARGUMENTS
  QSIZ	 (input) INTEGER
	 The dimension of the unitary matrix used to reduce the full matrix
	 to tridiagonal form.  QSIZ >= N if ICOMPQ = 1.

  N	 (input) INTEGER
	 The dimension of the symmetric tridiagonal matrix.  N >= 0.

  D	 (input/output) REAL array, dimension (N)
	 On entry, the diagonal elements of the tridiagonal matrix.  On exit,
	 the eigenvalues in ascending order.

  E	 (input/output) REAL array, dimension (N-1)
	 On entry, the off-diagonal elements of the tridiagonal matrix.	 On
	 exit, E has been destroyed.

  Q	 (input/output) COMPLEX array, dimension (LDQ,N)
	 On entry, Q must contain an QSIZ x N matrix whose columns unitarily
	 orthonormal. It is a part of the unitary matrix that reduces the
	 full dense Hermitian matrix to a (reducible) symmetric tridiagonal
	 matrix.

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

  IWORK	 (workspace) INTEGER array,
	 the dimension of IWORK must be at least 6 + 6*N + 5*N*lg N ( lg( N )
	 = smallest integer k such that 2^k >= N )

  RWORK	 (workspace) REAL array,
	 dimension (1 + 3*N + 2*N*lg N + 3*N**2) ( lg( N ) = smallest integer
	 k such that 2^k >= N )

	 QSTORE (workspace) COMPLEX array, dimension (LDQS, N) Used to store
	 parts of the eigenvector matrix when the updating matrix multiplies
	 take place.

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

  INFO	 (output) INTEGER
	 = 0:  successful exit.
	 < 0:  if INFO = -i, the i-th argument had an illegal value.
	 > 0:  The algorithm failed to compute an eigenvalue while working on
	 the submatrix lying in rows and columns INFO/(N+1) through
	 mod(INFO,N+1).