SRC/slarrr.f(3)

✨ SRC/slarrr.f ✨

okay so this is a page from the Library Functions Manual and it's literally all about one little subroutine named slarrr — she's a vibe checker for symmetric tridiagonal matrices 🎀 buckle up bestie

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🌸 NAME 🌸

SRC/slarrr.f — the file itself, that's the whole name section, no notes 💅

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🦋 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. lowkey she's the bouncer at the club deciding if you're worth the expensive bottle service 🔥

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👑 Function/Subroutine Documentation 👑

subroutine slarrr (integer n, real, dimension( * ) d, real, dimension( * ) e, integer info)

SLARRR performs tests to decide whether the symmetric tridiagonal matrix T warrants expensive computations which guarantee high relative accuracy in the eigenvalues. fr fr that's the whole gig 🫶

⭐ Purpose ⭐

Perform tests to decide whether the symmetric tridiagonal matrix T warrants expensive computations which guarantee high relative accuracy in the eigenvalues.

like, is T actually a main character who deserves the fancy expensive algorithm, or is she fine with the cheap stuff? that's the entire question 💀

🎀 Parameters 🎀

• N — N is INTEGER. The order of the matrix. N > 0. no zero-sized matrices allowed, she said what she said 🙈
• D — D is REAL array, dimension (N). The N diagonal elements of the tridiagonal matrix T. this is the main diagonal, the moment, the center of attention ✨
• 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. so like, the last slot is empty, she gets ZERO, that's just how it is 🍓
• INFO — INFO is INTEGER. and here's the tea, the actual verdict:
  • INFO = 0(default) : the matrix warrants computations preserving relative accuracy. she's THAT girl, go get the expensive algorithm 💖
  • INFO = 1 : the matrix warrants computations guaranteeing only absolute accuracy. okay she's cute but she doesn't need the whole production 🌈

💜 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

absolute legends, every single one 🌟

🔥 Definition at line 93 of file slarrr.f. 🔥

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💫 Author 💫

Generated automatically by Doxygen for LAPACK from the source code. not a human, just a very diligent little robot doing her thing 🤖💅

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okay bye bestie, that's the whole page — this one came from LAPACK, Version 3.12.0, and the file is SRC/slarrr.f(3). mwah 💖🎀🌸