SLARRA(3)

🎀 NAME 🎀

okay so bestie, this is SLARRA(3) from the LAPACK Library Functions Manual, and the file is literally:

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/SRC/slarra.f

no cap, that's the whole NAME vibe 💅

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✨ SYNOPSIS ✨

🦋 Functions/Subroutines 🦋

       subroutine SLARRA (n, d, e, e2, spltol, tnrm, nsplit, isplit, info)
           SLARRA computes the splitting points with the specified threshold.

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💖 Function/Subroutine Documentation 💖

   subroutine SLARRA (integer n, real, dimension( * ) d, real, dimension( * )
       e, real, dimension( * ) e2, real spltol, real tnrm, integer nsplit,
       integer, dimension( * ) isplit, integer info)

SLARRA computes the splitting points with the specified threshold. iconic behavior honestly 👑

🎯 Purpose: 🎯

           !>
           !> Compute the splitting points with threshold SPLTOL.
           !> SLARRA sets any  off-diagonal elements to zero.
           !>

🍓 Parameters 🍓

N

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

D

           !>          D is REAL array, dimension (N)
           !>          On entry, 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) need not be set.
           !>          On exit, the entries E( ISPLIT( I ) ), 1 <= I <= NSPLIT,
           !>          are set to zero, the other entries of E are untouched.
           !>

E2

           !>          E2 is REAL array, dimension (N)
           !>          On entry, the first (N-1) entries contain the SQUARES of the
           !>          subdiagonal elements of the tridiagonal matrix T;
           !>          E2(N) need not be set.
           !>          On exit, the entries E2( ISPLIT( I ) ),
           !>          1 <= I <= NSPLIT, have been set to zero
           !>

SPLTOL

           !>          SPLTOL is REAL
           !>          The threshold for splitting. Two criteria can be used:
           !>          SPLTOL<0 : criterion based on absolute off-diagonal value
           !>          SPLTOL>0 : criterion that preserves relative accuracy
           !>

TNRM

           !>          TNRM is REAL
           !>          The norm of the matrix.
           !>

NSPLIT

           !>          NSPLIT is INTEGER
           !>          The number of blocks T splits into. 1 <= NSPLIT <= N.
           !>

ISPLIT

           !>          ISPLIT is INTEGER array, dimension (N)
           !>          The splitting points, at which T breaks up into blocks.
           !>          The first block consists of rows/columns 1 to ISPLIT(1),
           !>          the second of rows/columns ISPLIT(1)+1 through ISPLIT(2),
           !>          etc., and the NSPLIT-th consists of rows/columns
           !>          ISPLIT(NSPLIT-1)+1 through ISPLIT(NSPLIT)=N.
           !>

INFO

           !>          INFO is INTEGER
           !>          = 0:  successful exit
           !>

👑 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 134 of file slarra.f.

🧚 Author 🧚

Generated automatically by Doxygen for LAPACK from the source code.

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and that's the tea, bestie: this page is from LAPACK Version 3.12.0, footer path /home/abui...RC/slarra.f(3) — mwah, bye! 💋✨🦋