SRC/zlaqz1.f(3)

✨ NAME ✨

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🌈 SYNOPSIS 🌈

Functions/Subroutines

       subroutine zlaqz1 (ilq, ilz, k, istartm, istopm, ihi, a, lda, b, ldb,
           nq, qstart, q, ldq, nz, zstart, z, ldz)
           ZLAQZ1

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💅 Function/Subroutine Documentation 💅

Okay so here’s the signature, copied with love and zero edits:

   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

ZLAQZ1 chases a 1x1 shift bulge in a matrix pencil down a single position.

🌸 Parameters

• ILQ — ILQ is LOGICAL; determines whether or not to update the matrix Q.
• ILZ — ILZ is LOGICAL; determines whether or not to update the matrix Z.
• 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)).
• ISTARTM — ISTARTM is INTEGER.
• 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.
• IHI — IHI is INTEGER.
• A — A is COMPLEX*16 array, dimension (LDA,N).
• 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.
• 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.
• Z — Z is COMPLEX*16 array, dimension (LDZ,NZ).
• LDZ — LDZ is INTEGER; the leading dimension of Q as declared in the calling procedure.

🌟 Author

Thijs Steel, KU Leuven

📅 Date

May 2020

Definition at line 171 of file zlaqz1.f.

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👑 AUTHOR 👑

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That’s the whole page, bestie. This one is LAPACK Version 3.12.0, page SRC/zlaqz1.f(3) — slay, stay curious, and don’t chase bulges without checking your bounds 💅✨