ZLAQZ1(3)

💖 NAME 💖

Okay bestie, this page is for ZLAQZ1(3) — yes, the manual name is right there. The NAME section in the original is literally this file path:

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/SRC/zlaqz1.f

Highkey iconic. It's giving Fortran source file energy. 🫶

✨ SYNOPSIS ✨

Functions/Subroutines

subroutine ZLAQZ1 (ilq, ilz, k, istartm, istopm, ihi, a, lda, b, ldb,
    nq, qstart, q, ldq, nz, zstart, z, ldz)
    ZLAQZ1

🌸 Function/Subroutine Documentation 🌸

subroutine ZLAQZ1 (logical, intent(in) ilq, logical, intent(in) ilz,
    integer, intent(in) k, integer, intent(in) istartm, integer, intent(in)
    istopm, integer, intent(in) ihi, complex*16, dimension( lda, * ) a,
    integer, intent(in) lda, complex*16, dimension( ldb, * ) b, integer,
    intent(in) ldb, integer, intent(in) nq, integer, intent(in) qstart,
    complex*16, dimension( ldq, * ) q, integer, intent(in) ldq, integer,
    intent(in) nz, integer, intent(in) zstart, complex*16, dimension( ldz, *
    ) z, integer, intent(in) ldz)
    ZLAQZ1

Purpose

Literally: ZLAQZ1 chases a 1x1 shift bulge in a matrix pencil down a single position. That's the whole vibe. 🌀

Parameters

• ILQ — ILQ is LOGICAL. It determines whether or not to update the matrix Q. (So, like, Q gets a glow-up only if this is true, bestie. 💅)
• ILZ — ILZ is LOGICAL. It determines whether or not to update the matrix Z. (Z's makeover is also optional. ✨)
• K — K is INTEGER. Index indicating the position of the bulge. On entry, the bulge is located in (A(k+1,k),B(k+1,k)). On exit, the bulge is located in (A(k+2,k+1),B(k+2,k+1)). So the bulge literally moves, no cap. 🫧
• ISTARTM — ISTARTM is INTEGER. That's it. That's the whole description. 💀
• ISTOPM — ISTOPM is INTEGER. Updates to (A,B) are restricted to (istartm:k+2,k:istopm). It is assumed without checking that istartm <= k+1 and k+2 <= istopm. (So please don't make it weird, because it will not check. 🙈)
• IHI — IHI is INTEGER. Again, that's the entire description. Iconic minimalism. ✨
• A — A is COMPLEX*16 array, dimension (LDA,N). Yes bestie, that's the exact type in the source. 💜
• LDA — LDA is INTEGER. The leading dimension of A as declared in the calling procedure.
• B — B is COMPLEX*16 array, dimension (LDB,N).
• LDB — LDB is INTEGER. The leading dimension of B as declared in the calling procedure.
• NQ — NQ is INTEGER. The order of the matrix Q.
• QSTART — QSTART is INTEGER. Start index of the matrix Q. Rotations are applied to columns k+2-qStart:k+3-qStart of Q. (The original says To with a capital T, and honestly? Slay. 💅)
• Q — Q is COMPLEX*16 array, dimension (LDQ,NQ).
• LDQ — LDQ is INTEGER. The leading dimension of Q as declared in the calling procedure.
• NZ — NZ is INTEGER. The order of the matrix Z.
• ZSTART — ZSTART is INTEGER. Start index of the matrix Z. Rotations are applied to columns k+1-qStart:k+2-qStart of Z. Again with the capital S in qStart, and yes, I'm keeping it exactly as written. 🎀
• Z — Z is COMPLEX*16 array, dimension (LDZ,NZ).
• LDZ — LDZ is INTEGER. The leading dimension of Q as declared in the calling procedure. Wait — yes, the original literally says Q here, not Z. Not me editing it, bestie. That's the source. 💀

Author

Thijs Steel, KU Leuven. 💖

Date

May 2020. 🗓️

Definition

Definition at line 171 of file zlaqz1.f.

Author

Generated automatically by Doxygen for LAPACK from the source code. (So this whole page is Doxygen's auto-generated child, and we're just giving it main character energy. 👑)

---

Okay that’s the whole page, bestie 💖 — it’s from LAPACK Version 3.12.0, source path /home/abui...RC/zlaqz1.f(3), with the Date section saying May 2020. Byeee 🌈✨