1SLARRC(1)           LAPACK auxiliary routine (version 3.2)           SLARRC(1)
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NAME

6       SLARRC  - the number of eigenvalues of the symmetric tridiagonal matrix
7       T that are in the interval (VL,VU] if JOBT = 'T', and of  L  D  L^T  if
8       JOBT = 'L'
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SYNOPSIS

11       SUBROUTINE SLARRC( JOBT,  N,  VL, VU, D, E, PIVMIN, EIGCNT, LCNT, RCNT,
12                          INFO )
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14           CHARACTER      JOBT
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16           INTEGER        EIGCNT, INFO, LCNT, N, RCNT
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18           REAL           PIVMIN, VL, VU
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20           REAL           D( * ), E( * )
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PURPOSE

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

28       JOBT    (input) CHARACTER*1
29               = 'T':  Compute Sturm count for matrix T.
30               = 'L':  Compute Sturm count for matrix L D L^T.
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32       N       (input) INTEGER
33               The order of the matrix. N > 0.
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35       VL      (input) DOUBLE PRECISION
36               VU      (input) DOUBLE PRECISION The lower and upper bounds for
37               the eigenvalues.
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39       D       (input) DOUBLE PRECISION array, dimension (N)
40               JOBT  =  'T': The N diagonal elements of the tridiagonal matrix
41               T.
42               JOBT = 'L': The N diagonal elements of the diagonal matrix D.
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44       E       (input) DOUBLE PRECISION array, dimension (N)
45               JOBT = 'T': The N-1 offdiagonal elements of the matrix T.
46               JOBT = 'L': The N-1 offdiagonal elements of the matrix L.
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48       PIVMIN  (input) DOUBLE PRECISION
49               The minimum pivot in the Sturm sequence for T.
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51       EIGCNT  (output) INTEGER
52               The number of eigenvalues of the symmetric tridiagonal matrix T
53               that are in the interval (VL,VU]
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55       LCNT    (output) INTEGER
56               RCNT     (output)  INTEGER  The left and right negcounts of the
57               interval.
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59       INFO    (output) INTEGER
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FURTHER DETAILS

62       Based on contributions by
63          Beresford Parlett, University of California, Berkeley, USA
64          Jim Demmel, University of California, Berkeley, USA
65          Inderjit Dhillon, University of Texas, Austin, USA
66          Osni Marques, LBNL/NERSC, USA
67          Christof Voemel, University of California, Berkeley, USA
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71 LAPACK auxiliary routine (versionNo3v.e2m)ber 2008                       SLARRC(1)
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