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

NAME

       LAPACK-3  -  tests to decide whether the symmetric tridiagonal matrix T warrants expensive
       computations which guarantee high relative accuracy in the eigenvalues

SYNOPSIS

       SUBROUTINE DLARRR( N, D, E, INFO )

           INTEGER        N, INFO

           DOUBLE         PRECISION D( * ), E( * )

PURPOSE

       Perform tests to decide whether the symmetric  tridiagonal  matrix  T  warrants  expensive
       computations which guarantee high relative accuracy in the eigenvalues.

ARGUMENTS

        N       (input) INTEGER
                The order of the matrix. N > 0.

        D       (input) DOUBLE PRECISION array, dimension (N)
                The N diagonal elements of the tridiagonal matrix T.

        E       (input/output) DOUBLE PRECISION array, dimension (N)
                On entry, the first (N-1) entries contain the subdiagonal
                elements of the tridiagonal matrix T; E(N) is set to ZERO.

        INFO    (output) INTEGER
                INFO = 0(default) : the matrix warrants computations preserving
                relative accuracy.
                INFO = 1          : the matrix warrants computations guaranteeing
                only absolute accuracy.

FURTHER DETAILS

        Based on contributions by
           Beresford Parlett, University of California, Berkeley, USA
           Jim Demmel, University of California, Berkeley, USA
           Inderjit Dhillon, University of Texas, Austin, USA
           Osni Marques, LBNL/NERSC, USA
           Christof Voemel, University of California, Berkeley, USA

 LAPACK auxiliary routine (version 3.2)     April 2011                            DLARRR(3lapack)