CLAQZ2(3)

🎀 NAME 🎀

okay so this page is CLAQZ2(3), and it comes from the Library Functions Manual. The NAME section is literally just this path, no extra lore, no nothing:

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/SRC/claqz2.f

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✨ SYNOPSIS ✨

🧚 Functions/Subroutines 🧚

Here's the whole recursive-subroutine vibe, exactly as written:

recursive subroutine CLAQZ2 (ilschur, ilq, ilz, n, ilo, ihi, nw, a, lda,
    b, ldb, q, ldq, z, ldz, ns, nd, alpha, beta, qc, ldqc, zc, ldzc,
    work, lwork, rwork, rec, info)
    CLAQZ2

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🫶 Function/Subroutine Documentation 🫶

💜 recursive subroutine CLAQZ2 💜

Full typed signature, bestie — every type, dimension, and intent exactly where the page puts it:

recursive subroutine CLAQZ2 (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) nw,
    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,
    integer, intent(out) ns, integer, intent(out) nd, complex, dimension( *
    ), intent(inout) alpha, complex, dimension( * ), intent(inout) beta,
    complex, dimension( ldqc, * ) qc, integer, intent(in) ldqc, complex,
    dimension( ldzc, * ) zc, integer, intent(in) ldzc, complex, dimension( *
    ) work, integer, intent(in) lwork, real, dimension( * ) rwork, integer,
    intent(in) rec, integer, intent(out) info)
    CLAQZ2

✨ Purpose ✨

The Purpose section is short and iconic: CLAQZ2 performs AED. That's it. That's the whole purpose. 💅

🌸 Parameters 🌸

• ILSCHUR — LOGICAL, intent(in). It's described as ILSCHUR is LOGICAL. It determines whether or not to update the full Schur form.
• ILQ — LOGICAL, intent(in). It's described as ILQ is LOGICAL. It determines whether or not to update the matrix Q.
• ILZ — LOGICAL, intent(in). It's described as ILZ is LOGICAL. It determines whether or not to update the matrix Z.
• N — INTEGER, intent(in). It's described as N is INTEGER. It's the order of the matrices A, B, Q, and Z. N >= 0.
• ILO — INTEGER, intent(in). It's described as ILO is INTEGER.
• IHI — INTEGER, intent(in). It's described as IHI is INTEGER. ILO and IHI mark the rows and columns of (A,B) which are to be normalized.
• NW — INTEGER, intent(in). It's described as NW is INTEGER. It's the desired size of the deflation window.
• A — COMPLEX array, dimension (LDA, N), intent(inout). It's described as A is COMPLEX array, dimension (LDA, N).
• LDA — INTEGER, intent(in). It's described as LDA is INTEGER. It's the leading dimension of the array A. LDA >= max( 1, N ).
• B — COMPLEX array, dimension (LDB, N), intent(inout). It's described as B is COMPLEX array, dimension (LDB, N).
• LDB — INTEGER, intent(in). It's described as LDB is INTEGER. It's the leading dimension of the array B. LDB >= max( 1, N ).
• Q — COMPLEX array, dimension (LDQ, N), intent(inout). It's described as Q is COMPLEX array, dimension (LDQ, N).
• LDQ — INTEGER, intent(in). It's described as LDQ is INTEGER.
• Z — COMPLEX array, dimension (LDZ, N), intent(inout). It's described as Z is COMPLEX array, dimension (LDZ, N).
• LDZ — INTEGER, intent(in). It's described as LDZ is INTEGER.
• NS — INTEGER, intent(out). It's described as NS is INTEGER. It's the number of unconverged eigenvalues available to use as shifts.
• ND — INTEGER, intent(out). It's described as ND is INTEGER. It's the number of converged eigenvalues found.
• ALPHA — COMPLEX array, dimension (N), intent(inout). It's described as ALPHA is COMPLEX array, dimension (N). Each scalar alpha defining an eigenvalue of GNEP.
• BETA — COMPLEX array, dimension (N), intent(inout). It's described as BETA is COMPLEX array, dimension (N). The scalars beta that define the eigenvalues of GNEP. Together, the quantities alpha = ALPHA(j) and beta = BETA(j) represent the j-th eigenvalue of the matrix pair (A,B), in one of the forms lambda = alpha/beta or mu = beta/alpha. Since either lambda or mu may overflow, they should not, in general, be computed.
• QC — COMPLEX array, dimension (LDQC, NW). No intent is listed in the typed signature. It's described as QC is COMPLEX array, dimension (LDQC, NW).
• LDQC — INTEGER, intent(in). It's described as LDQC is INTEGER.
• ZC — COMPLEX array, dimension (LDZC, NW). No intent is listed in the typed signature. It's described as ZC is COMPLEX array, dimension (LDZC, NW).
• LDZC — INTEGER, intent(in). The page's description here literally says LDZ is INTEGER — yes, LDZ, not LDZC; I'm just relaying the source, bestie. 😭
• WORK — COMPLEX array, dimension (MAX(1,LWORK)). No intent is listed in the typed signature. It's described as WORK is COMPLEX array, dimension (MAX(1,LWORK)). On exit, if INFO >= 0, WORK(1) returns the optimal LWORK.
• LWORK — INTEGER, intent(in). It's described as LWORK is INTEGER. It's 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.

• RWORK — REAL array, dimension (N). No intent is listed in the typed signature. It's described as RWORK is REAL array, dimension (N).
• REC — INTEGER, intent(in). It's described as REC is INTEGER. REC indicates the current recursion level. Should be set to 0 on first call.
• INFO — INTEGER, intent(out). It's described as INFO is INTEGER.
  • = 0: successful exit
  • < 0: if INFO = -i, the i-th argument had an illegal value

🧚 Author 🧚

Thijs Steel, KU Leuven, KU Leuven

📅 Date 📅

May 2020

📍 Definition at line 231 of file claqz2.f. 📍

Definition at line 231 of file claqz2.f.

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🧚 Author 🧚

Generated automatically by Doxygen for LAPACK from the source code.

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okay bye bestie 🫶💖 — this was LAPACK Version 3.12.0, dated May 2020, from /home/abui...RC/claqz2.f(3). periodt. ✨