SLAQZ1(3)

📦 version 3.12.0, in opensuse-leap 16.0

💅 SLAQZ1(3) — Library Functions Manual 💅

Okay bestie, welcome to SLAQZ1(3) from the Library Functions Manual — we're about to make this LAPACK subroutine make sense, no cap. ✨

🌸 NAME 🌸

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/SRC/slaqz1.f

✨ SYNOPSIS ✨

Functions/Subroutines

subroutine SLAQZ1 (a, lda, b, ldb, sr1, sr2, si, beta1, beta2, v)

SLAQZ1

🦋 Function/Subroutine Documentation 🦋

subroutine SLAQZ1 (real, dimension( lda, * ), intent(in) a, integer,
     intent(in) lda, real, dimension( ldb, * ), intent(in) b, integer,
     intent(in) ldb, real, intent(in) sr1, real, intent(in) sr2, real,
     intent(in) si, real, intent(in) beta1, real, intent(in) beta2, real,
     dimension( * ), intent(out) v)

SLAQZ1

🎯 Purpose 🎯

Okay so here's the whole vibe: given a 3-by-3 matrix pencil (A,B), SLAQZ1 sets v to a scalar multiple of the first column of the product

(*)  K = (A - (beta2*sr2 - i*si)*B)*B^(-1)*(beta1*A - (sr2 + i*si2)*B)*B^(-1).

It is assumed that either 1) sr1 = sr2 or 2) si = 0.

This is useful for starting double implicit shift bulges in the QZ algorithm. Periodt. 🔥

🧸 Parameters 🧸

  • A — A is a REAL array, dimension (LDA,N). It's the 3-by-3 matrix A in (*).
  • LDA — LDA is an INTEGER, the leading dimension of A as declared in the calling procedure.
  • B — B is a REAL array, dimension (LDB,N). It's the 3-by-3 matrix B in (*).
  • LDB — LDB is an INTEGER, the leading dimension of B as declared in the calling procedure.
  • SR1 — SR1 is REAL.
  • SR2 — SR2 is REAL.
  • SI — SI is REAL.
  • BETA1 — BETA1 is REAL.
  • BETA2 — BETA2 is REAL.
  • V — V is a REAL array, dimension (N). It gets a scalar multiple of the first column of the matrix K in (*).

👑 Author 👑

Thijs Steel, KU Leuven

📅 Date 📅

May 2020

Definition at line 125 of file slaqz1.f.

🤖 Author 🤖

Generated automatically by Doxygen for LAPACK from the source code.

That's the whole page, bestie 💖 — big thanks to LAPACK Version 3.12.0, and the cute little footer path is /home/abui...RC/slaqz1.f(3) (with May 2020 chillin' up there in the Date section). 🎀🫶

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