SRC/claqz3.f(3)

✨ SRC/claqz3.f — LAPACK Library Functions Manual ✨

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🌸 NAME 🌸

SRC/claqz3.f

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🦋 SYNOPSIS 🦋

Functions/Subroutines

       subroutine claqz3 (ilschur, ilq, ilz, n, ilo, ihi, nshifts,
           nblock_desired, alpha, beta, a, lda, b, ldb, q, ldq, z, ldz, qc,
           ldqc, zc, ldzc, work, lwork, info)
           CLAQZ3

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👑 Function/Subroutine Documentation 👑

subroutine claqz3

   subroutine claqz3 (logical, intent(in) ilschur, logical, intent(in) ilq,
       logical, intent(in) ilz, integer, intent(in) n, integer, intent(in) ilo,
       integer, intent(in) ihi, integer, intent(in) nshifts, integer,
       intent(in) nblock_desired, complex, dimension( * ), intent(inout) alpha,
       complex, dimension( * ), intent(inout) beta, complex, dimension( lda, *
       ), intent(inout) a, integer, intent(in) lda, complex, dimension( ldb, *
       ), intent(inout) b, integer, intent(in) ldb, complex, dimension( ldq, *
       ), intent(inout) q, integer, intent(in) ldq, complex, dimension( ldz, *
       ), intent(inout) z, integer, intent(in) ldz, complex, dimension( ldqc, *
       ), intent(inout) qc, integer, intent(in) ldqc, complex, dimension( ldzc,
       * ), intent(inout) zc, integer, intent(in) ldzc, complex, dimension( *
       ), intent(inout) work, integer, intent(in) lwork, integer, intent(out)
       info)
       CLAQZ3

🎀 Purpose 🎀

CLAQZ3 Executes a single multishift QZ sweep 💅

🌈 Parameters 🌈

• ILSCHUR — ILSCHUR is LOGICAL. Determines whether or not to update the full Schur form.
• 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.
• N — N is INTEGER. The order of the matrices A, B, Q, and Z. N >= 0.
• ILO — ILO is INTEGER.
• IHI — IHI is INTEGER.
• NSHIFTS — NSHIFTS is INTEGER. The desired number of shifts to use.
• NBLOCK_DESIRED — NBLOCK_DESIRED is INTEGER. The desired size of the computational windows.
• ALPHA — ALPHA is COMPLEX array. SR contains the alpha parts of the shifts to use.
• BETA — BETA is COMPLEX array. SS contains the scale of the shifts to use.
• A — A is COMPLEX array, dimension (LDA, N).
• LDA — LDA is INTEGER. The leading dimension of the array A. LDA >= max( 1, N ).
• B — B is COMPLEX array, dimension (LDB, N).
• LDB — LDB is INTEGER. The leading dimension of the array B. LDB >= max( 1, N ).
• Q — Q is COMPLEX array, dimension (LDQ, N).
• LDQ — LDQ is INTEGER.
• Z — Z is COMPLEX array, dimension (LDZ, N).
• LDZ — LDZ is INTEGER.
• QC — QC is COMPLEX array, dimension (LDQC, NBLOCK_DESIRED).
• LDQC — LDQC is INTEGER.
• ZC — ZC is COMPLEX array, dimension (LDZC, NBLOCK_DESIRED).
• LDZC — LDZC is INTEGER. The description line here literally says LDZ is INTEGER, exactly as written in the source doc block 💅
• WORK — WORK is COMPLEX array, dimension (MAX(1,LWORK)). On exit, if INFO >= 0, WORK(1) returns the optimal LWORK.
• LWORK — LWORK is INTEGER. The dimension of the array WORK. LWORK >= max(1,N).

If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal size of the WORK array, returns this value as the first entry of the WORK array, and no error message related to LWORK is issued by XERBLA.

• INFO — INFO is INTEGER.
  • = 0: successful exit
  • < 0: if INFO = -i, the i-th argument had an illegal value

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💜 Author 💜

Thijs Steel, KU Leuven

🍓 Date 🍓

May 2020

⭐ Definition ⭐

Definition at line 203 of file claqz3.f.

🧚 Author 🧚

Generated automatically by Doxygen for LAPACK from the source code.

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