slarrc.f man page

slarrc.f —

Synopsis

Functions/Subroutines

subroutine slarrc (JOBT, N, VL, VU, D, E, PIVMIN, EIGCNT, LCNT, RCNT, INFO)
SLARRC computes the number of eigenvalues of the symmetric tridiagonal matrix.

Function/Subroutine Documentation

subroutine slarrc (characterJOBT, integerN, realVL, realVU, real, dimension( * )D, real, dimension( * )E, realPIVMIN, integerEIGCNT, integerLCNT, integerRCNT, integerINFO)

SLARRC 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

VU

VU is DOUBLE PRECISION
The lower and upper bounds 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 REAL
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.

Date:

September 2012

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 136 of file slarrc.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

slarrc(3) is an alias of slarrc.f(3).

Sat Nov 16 2013 Version 3.4.2 LAPACK