DLAQZ1(3)

💅 DLAQZ1(3) 💅

okay bestie, welcome to DLAQZ1(3) from the Library Functions Manual ✨ this is a whole subroutine page and it's giving very specific linear-algebra main character energy, no cap. 💜

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🌸 NAME 🌸

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/SRC/dlaqz1.f

that's the full path, bestie — yes it's long, yes it's iconic, periodt. 🫶

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🦋 SYNOPSIS 🦋

✨ Functions/Subroutines ✨

subroutine DLAQZ1 (a, lda, b, ldb, sr1, sr2, si, beta1, beta2, v)
    DLAQZ1

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🧚 Function/Subroutine Documentation 🧚

subroutine DLAQZ1 (double precision, dimension( lda, * ), intent(in) a,
    integer, intent(in) lda, double precision, dimension( ldb, * ),
    intent(in) b, integer, intent(in) ldb, double precision, intent(in) sr1,
    double precision, intent(in) sr2, double precision, intent(in) si,
    double precision, intent(in) beta1, double precision, intent(in) beta2,
    double precision, dimension( * ), intent(out) v)
    DLAQZ1

💖 Purpose 💖

so here's the vibe: given a 3-by-3 matrix pencil (A,B), DLAQZ1 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's assumed that either

1) sr1 = sr2

or

2) si = 0.

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

🎀 Parameters 🎀

• A — A is DOUBLE PRECISION array, dimension (LDA,N). The 3-by-3 matrix A in (*). 💜
• LDA — LDA is INTEGER. The leading dimension of A as declared in the calling procedure.
• B — B is DOUBLE PRECISION array, dimension (LDB,N). The 3-by-3 matrix B in (*). 🦋
• LDB — LDB is INTEGER. The leading dimension of B as declared in the calling procedure.
• SR1 — SR1 is DOUBLE PRECISION. 🌸
• SR2 — SR2 is DOUBLE PRECISION. 🌸
• SI — SI is DOUBLE PRECISION. 🌸
• BETA1 — BETA1 is DOUBLE PRECISION. 🌸
• BETA2 — BETA2 is DOUBLE PRECISION. 🌸
• V — V is DOUBLE PRECISION array, dimension (N). 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 dlaqz1.f.

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🤖 Author 🤖

Generated automatically by Doxygen for LAPACK from the source code.

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mwah 💖 this page is LAPACK Version 3.12.0, dated May 2020, and the footer path is /home/abui...RC/dlaqz1.f(3). k bye bestie, slay your linear algebra 🎀✨