# slarrr.f(3) [centos man page]

slarrr.f(3) LAPACK slarrr.f(3)NAME

slarrr.f-SYNOPSIS

Functions/Subroutines subroutine slarrr (N, D, E, INFO) SLARRR performs tests to decide whether the symmetric tridiagonal matrix T warrants expensive computations which guarantee high relative accuracy in the eigenvalues.Function/Subroutine Documentation subroutine slarrr (integerN, real, dimension( * )D, real, dimension( * )E, integerINFO) SLARRR performs tests to decide whether the symmetric tridiagonal matrix T warrants expensive computations which guarantee high relative accuracy in the eigenvalues. Purpose: Perform tests to decide whether the symmetric tridiagonal matrix T warrants expensive computations which guarantee high relative accuracy in the eigenvalues. Parameters: N N is INTEGER The order of the matrix. N > 0. D D is REAL array, dimension (N) The N diagonal elements of the tridiagonal matrix T. E 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 INFO is INTEGER INFO = 0(default) : the matrix warrants computations preserving relative accuracy. INFO = 1 : the matrix warrants computations guaranteeing only absolute accuracy. 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 95 of file slarrr.f.AuthorGenerated automatically by Doxygen for LAPACK from the source code.Version 3.4.2Tue Sep 25 2012 slarrr.f(3)

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slarrc.f(3) LAPACK slarrc.f(3)NAME

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.AuthorGenerated automatically by Doxygen for LAPACK from the source code.Version 3.4.2Tue Sep 25 2012 slarrc.f(3)