Provided by: liblapack-doc_3.3.1-1_all bug

NAME

       LAPACK-3  -  the divide and conquer method, ZLAED0 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

SYNOPSIS

       SUBROUTINE ZLAED0( QSIZ, N, D, E, Q, LDQ, QSTORE, LDQS, RWORK, IWORK, INFO )

           INTEGER        INFO, LDQ, LDQS, N, QSIZ

           INTEGER        IWORK( * )

           DOUBLE         PRECISION D( * ), E( * ), RWORK( * )

           COMPLEX*16     Q( LDQ, * ), QSTORE( LDQS, * )

PURPOSE

       Using  the  divide  and  conquer  method,  ZLAED0  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) DOUBLE PRECISION array, dimension (N)
               On entry, the diagonal elements of the tridiagonal matrix.
               On exit, the eigenvalues in ascending order.

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

        Q      (input/output) COMPLEX*16 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) DOUBLE PRECISION 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*16 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).

 LAPACK routine (version 3.2)               April 2011                            ZLAED0(3lapack)