SRC/dlarrc.f(3)            Library Functions Manual            SRC/dlarrc.f(3)

NAME
       SRC/dlarrc.f

SYNOPSIS
   Functions/Subroutines
       subroutine dlarrc (jobt, n, vl, vu, d, e, pivmin, eigcnt, lcnt, rcnt,
           info)
           DLARRC computes the number of eigenvalues of the symmetric
           tridiagonal matrix.

Function/Subroutine Documentation
   subroutine dlarrc (character jobt, integer n, double precision vl, double
       precision vu, double precision, dimension( * ) d, double precision,
       dimension( * ) e, double precision pivmin, integer eigcnt, integer
       lcnt, integer rcnt, integer info)
       DLARRC computes the number of eigenvalues of the symmetric tridiagonal
       matrix.

       Purpose:


            Find the number of eigenvalues of the symmetric tridiagonal matrix T
            that are in the interval (VL,VU] if JOBT = 'T', and of L D L^T
            if JOBT = 'L'.

       Parameters
           JOBT

                     JOBT is CHARACTER*1
                     = 'T':  Compute Sturm count for matrix T.
                     = 'L':  Compute Sturm count for matrix L D L^T.

           N

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

           VL

                     VL is DOUBLE PRECISION
                     The lower bound for the eigenvalues.

           VU

                     VU is DOUBLE PRECISION
                     The upper bound for the eigenvalues.

           D

                     D is DOUBLE PRECISION array, dimension (N)
                     JOBT = 'T': The N diagonal elements of the tridiagonal matrix T.
                     JOBT = 'L': The N diagonal elements of the diagonal matrix D.

           E

                     E is DOUBLE PRECISION array, dimension (N)
                     JOBT = 'T': The N-1 offdiagonal elements of the matrix T.
                     JOBT = 'L': The N-1 offdiagonal elements of the matrix L.

           PIVMIN

                     PIVMIN is DOUBLE PRECISION
                     The minimum pivot in the Sturm sequence for T.

           EIGCNT

                     EIGCNT is INTEGER
                     The number of eigenvalues of the symmetric tridiagonal matrix T
                     that are in the interval (VL,VU]

           LCNT

                     LCNT is INTEGER

           RCNT

                     RCNT is INTEGER
                     The left and right negcounts of the interval.

           INFO

                     INFO is INTEGER

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Contributors:
           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

       Definition at line 135 of file dlarrc.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.

LAPACK                          Version 3.12.0                 SRC/dlarrc.f(3)