TESTING/EIG/dlctes.f(3)

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version 3.12.1 · 3 versions
, in arch rolling

💅 TESTING/EIG/dlctes.f 💅

okay bestie, welcome to the little page for TESTING/EIG/dlctes.f — it's part of the LAPACK library's function docs, and honestly it's a whole vibe. it's short, it's sweet, it's a logical function that makes a decision and moves on with its life. main character energy fr.

✨ SYNOPSIS ✨

🧚 Functions/Subroutines

  • logical function dlctes (zr, zi, d) — the one and only, DLCTES

🦋 Function/Subroutine Documentation 🦋

logical function dlctes (double precision zr, double precision zi, double precision d)

yep, that's the signature. three double precision args walk into a function and it returns a logical. iconic.

DLCTES

🎀 Purpose:

!>
!> DLCTES returns .TRUE. if the eigenvalue (ZR/D) + sqrt(-1)*(ZI/D)
!> is to be selected (specifically, in this subroutine, if the real
!> part of the eigenvalue is negative), and otherwise it returns
!> .FALSE..
!>
!> It is used by the test routine DDRGES to test whether the driver
!> routine DGGES successfully sorts eigenvalues.
!>

so like, lowkey the whole job is: give it a complex eigenvalue written as (ZR/D) + sqrt(-1)*(ZI/D) and it hands back .TRUE. if that eigenvalue should be selected — and specifically, in this subroutine, that means the real part of the eigenvalue is negative. otherwise? .FALSE. periodt. 💅

and the reason it exists at all? it's the helper for the test routine DDRGES, which uses it to check whether the driver routine DGGES actually sorted the eigenvalues correctly. so it's basically the vibe-check for eigenvalue sorting. no cap. ✨

🌸 Parameters 🌸

  • ZR — is DOUBLE PRECISION. this is the numerator of the real part of a complex eigenvalue (ZR/D) + i*(ZI/D). bestie it's the top half of the fraction, ok? 🍓
!>          ZR is DOUBLE PRECISION
!>          The numerator of the real part of a complex eigenvalue
!>          (ZR/D) + i*(ZI/D).
!>
  • ZI — is DOUBLE PRECISION. the numerator of the imaginary part of a complex eigenvalue (ZR/D) + i*(ZI). yes, that's exactly how the original writes it — (ZR/D) + i*(ZI) — don't come for me, I'm just the messenger 💀
!>          ZI is DOUBLE PRECISION
!>          The numerator of the imaginary part of a complex eigenvalue
!>          (ZR/D) + i*(ZI).
!>
  • D — is DOUBLE PRECISION. the denominator part of a complex eigenvalue (ZR/D) + i*(ZI/D). it's giving shared responsibility. 🫶
!>          D is DOUBLE PRECISION
!>          The denominator part of a complex eigenvalue
!>          (ZR/D) + i*(ZI/D).
!>

👑 Author 👑

the whole squad on the credits:

  • Univ. of Tennessee
  • Univ. of California Berkeley
  • Univ. of Colorado Denver
  • NAG Ltd.

Definition at line 67 of file dlctes.f. like, go look, it's right there ⭐

🌈 Author 🌈

Generated automatically by Doxygen for LAPACK from the source code. bestie it literally wrote itself, we're just here for the vibes 🙈

kay that's the whole page, you ate that 💖 this was LAPACK, Version 3.12.0, of TESTING/EIG/dlctes.f(3) — slay and goodbye, mwah 🎀✨

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