CSLECT(3)

💅 NAME 💅

Okay bestie, welcome to CSLECT(3) from the Library Functions Manual — manual name folded in right here like a little name tag, no copying the header line. The file path is literally:

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/TESTING/EIG/cslect.f

So it's LAPACK testing-file energy, specifically the EIG folder, and the function is CSLECT. Periodt.

✨ SYNOPSIS ✨

Functions/Subroutines

   logical function CSLECT (z)
       CSLECT

That's the synopsis: logical function CSLECT (z), then CSLECT. Slay.

🦋 Function/Subroutine Documentation 🦋

logical function CSLECT (complex z)
    CSLECT

💫 Purpose 💫

Okay so here's the tea: CSLECT returns .TRUE. if the eigenvalue Z is to be selected, otherwise it returns .FALSE. No cap.

It is used by CCHK41 to test if CGEES successfully sorts eigenvalues, and by CCHK43 to test if CGEESX successfully sorts eigenvalues. Cute little sorting vibe check, fr fr.

The common block /SSLCT/ controls how eigenvalues are selected. So:

• If SELOPT = 0, then CSLECT return .TRUE. when real(Z) is less than zero, and .FALSE. otherwise. (Yes, "return" is in the original; keeping it exactly.)
• If SELOPT is at least 1, CSLECT returns SELVAL(SELOPT) and adds 1 to SELOPT, cycling back to 1 at SELMAX.

🎀 Parameters 🎀

• Z — Z is COMPLEX; it's the eigenvalue Z. That's the whole parameter, and she ate. 🫶

💜 Author 💜

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

Definition at line 55 of file cslect.f. Iconic line number, honestly.

🧚 Author (auto-generated edition) 🧚

Generated automatically by Doxygen for LAPACK from the source code.

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Source/version/date sign-off: LAPACK, Version 3.12.0 — footer tag: /home/abui...IG/cslect.f(3). No separate date on this footer, ngl; just version + path energy. 🎀✨