CLAEIN(3)

🌸 NAME 🌸

Hey bestie, welcome to CLAEIN(3) — this is the claein.f(3) page straight outta the Library Functions Manual 💅. The NAME is literally this file path:

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

No cap, that's the whole NAME section.

✨ SYNOPSIS ✨

🌟 Functions/Subroutines 🌟

       subroutine CLAEIN (rightv, noinit, n, h, ldh, w, v, b, ldb, rwork, eps3,
           smlnum, info)

CLAEIN computes a specified right or left eigenvector of an upper Hessenberg matrix by inverse iteration. Slay.

💖 Function/Subroutine Documentation 💖

🫶 subroutine CLAEIN 🫶

Full signature, exactly as it is:

       subroutine CLAEIN (logical rightv, logical noinit, integer n, complex,
           dimension( ldh, * ) h, integer ldh, complex w, complex, dimension( * )
           v, complex, dimension( ldb, * ) b, integer ldb, real, dimension( * )
           rwork, real eps3, real smlnum, integer info)

CLAEIN computes a specified right or left eigenvector of an upper Hessenberg matrix by inverse iteration.

🎯 Purpose 🎯

CLAEIN uses inverse iteration to find a right or left eigenvector corresponding to the eigenvalue W of a complex upper Hessenberg matrix H. That's the vibe: inverse iteration, eigenvectors, no drama.

📋 Parameters 📋

• RIGHTV — LOGICAL. Set it to .TRUE. and you're computing the right eigenvector; set it to .FALSE. and you're computing the left eigenvector.
• NOINIT — LOGICAL. Set it to .TRUE. and no initial vector is supplied in V; set it to .FALSE. and an initial vector is supplied in V.
• N — INTEGER, the order of the matrix H. Constraint: N >= 0.
• H — COMPLEX array, dimension (LDH,N), the upper Hessenberg matrix H.
• LDH — INTEGER, the leading dimension of the array H. Constraint: LDH >= max(1,N).
• W — COMPLEX, the eigenvalue of H whose corresponding right or left eigenvector is to be computed.
• V — COMPLEX array, dimension (N). On entry, if NOINIT = .FALSE., V must contain a starting vector for inverse iteration; otherwise V need not be set. On exit, V contains the computed eigenvector, normalized so that the component of largest magnitude has magnitude 1; here the magnitude of a complex number (x,y) is taken to be |x| + |y|.
• B — COMPLEX array, dimension (LDB,N).
• LDB — INTEGER, the leading dimension of the array B. Constraint: LDB >= max(1,N).
• RWORK — REAL array, dimension (N).
• EPS3 — REAL, a small machine-dependent value which is used to perturb close eigenvalues, and to replace zero pivots.
• SMLNUM — REAL, a machine-dependent value close to the underflow threshold.
• INFO — INTEGER. = 0: successful exit. = 1: inverse iteration did not converge; V is set to the last iterate.

👑 Author 👑

• Univ. of Tennessee
• Univ. of California Berkeley
• Univ. of Colorado Denver
• NAG Ltd.

Definition at line 147 of file claein.f.

👑 Author 👑

Generated automatically by Doxygen for LAPACK from the source code.

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That's the whole page, bestie 💅✨ — source/version: LAPACK Version 3.12.0, and the footer date/path is /home/abui...RC/claein.f(3). Bye! 🫶🎀