SRC/dlartgp.f(3)

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version 3.12.1 · 4 versions
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SRC/dlartgp.f(3) 💅

okay bestie, welcome to the SRC/dlartgp.f(3) page from the Library Functions Manual ✨ It’s the DLARTGP show, and the whole plot is: generate a plane rotation so that the diagonal is nonnegative. No cap, that’s the assignment 🎀

NAME 🦋

SRC/dlartgp.f — that’s the name, that’s the whole vibe. It’s giving “math file with main character energy” and honestly? Obsessed 💖

✨ SYNOPSIS ✨

Functions/Subroutines

subroutine dlartgp (f, g, cs, sn, r)
  • subroutine dlartgp (f, g, cs, sn, r) — DLARTGP generates a plane rotation so that the diagonal is nonnegative. Slay 🫶

🎀 Function/Subroutine Documentation 🎀

subroutine dlartgp (double precision f, double precision g, double precision cs, double precision sn, double precision r)

DLARTGP generates a plane rotation so that the diagonal is nonnegative. Periodt 💅

💖 Purpose 💖

okay so the purpose is literally this, bestie:

   [  CS  SN  ]  .  [ F ]  =  [ R ]   where CS**2 + SN**2 = 1.
   [ -SN  CS  ]     [ G ]     [ 0 ]

This is a slower, more accurate version of the Level 1 BLAS routine DROTG, with the following other differences:

  • F and G are unchanged on return. 🦋
  • If G=0, then CS=(+/-)1 and SN=0. ✨
  • If F=0 and (G .ne. 0), then CS=0 and SN=(+/-)1. 💫
  • The sign is chosen so that R >= 0. 👑

🌸 Parameters 🌸

  • F — F is DOUBLE PRECISION; the first component of vector to be rotated. 🌼
  • G — G is DOUBLE PRECISION; the second component of vector to be rotated. 🦋
  • CS — CS is DOUBLE PRECISION; the cosine of the rotation. ✨
  • SN — SN is DOUBLE PRECISION; the sine of the rotation. 💫
  • R — R is DOUBLE PRECISION; the nonzero component of the rotated vector. 👑
Tiny legacy note, no cap: This version has a few statements commented out for thread safety (machine parameters are computed on each entry). 10 feb 03, SJH. 📝

👑 Author 👑

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

Definition at line 94 of file dlartgp.f. 📍

Author 🧚

Generated automatically by Doxygen for LAPACK from the source code.

That’s the whole page, bestie 🫶 — LAPACK Version 3.12.0, SRC/dlartgp.f(3). Go rotate something responsibly 💅✨

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