SLARRR(3)      LAPACK routine of NEC Numeric Library Collection      SLARRR(3)



NAME
       SLARRR

SYNOPSIS
       SUBROUTINE SLARRR (N, D, E, INFO)



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)
                     N is INTEGER
                     The order of the matrix. N > 0.

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

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



LAPACK routine                  31 October 2017                      SLARRR(3)