1SLARRC(1)           LAPACK auxiliary routine (version 3.1)           SLARRC(1)
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NAME

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

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

63       Based on contributions by
64          Beresford Parlett, University of California, Berkeley, USA
65          Jim Demmel, University of California, Berkeley, USA
66          Inderjit Dhillon, University of Texas, Austin, USA
67          Osni Marques, LBNL/NERSC, USA
68          Christof Voemel, University of California, Berkeley, USA
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73 LAPACK auxiliary routine (versionNo3v.e1m)ber 2006                       SLARRC(1)
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