BLAS/SRC/srotmg.f(3)

📦
version 3.12.1 · 4 versions
, in arch rolling

💖 NAME 💖

Okay bestie, this page is from the Library Functions Manual, and the main character is BLAS/SRC/srotmg.f. 💅

🦋 SYNOPSIS 🦋

✨ Functions/Subroutines ✨

subroutine srotmg (sd1, sd2, sx1, sy1, sparam)
    SROTMG

🌸 FUNCTION/SUBROUTINE DOCUMENTATION 🌸

subroutine srotmg (real sd1, real sd2, real sx1, real sy1, real,
    dimension(5) sparam)
    SROTMG

✨ Purpose ✨

The purpose comment is the actual tea ☕, and I’m keeping it word-for-word because matrices are not the place to freestyle:

!>
!>    CONSTRUCT THE MODIFIED GIVENS TRANSFORMATION MATRIX H WHICH ZEROS
!>    THE SECOND COMPONENT OF THE 2-VECTOR  (SQRT(SD1)*SX1,SQRT(SD2)*>    SY2)**T.
!>    WITH SPARAM(1)=SFLAG, H HAS ONE OF THE FOLLOWING FORMS..
!>
!>    SFLAG=-1.E0     SFLAG=0.E0        SFLAG=1.E0     SFLAG=-2.E0
!>
!>      (SH11  SH12)    (1.E0  SH12)    (SH11  1.E0)    (1.E0  0.E0)
!>    H=(          )    (          )    (          )    (          )
!>      (SH21  SH22),   (SH21  1.E0),   (-1.E0 SH22),   (0.E0  1.E0).
!>    LOCATIONS 2-4 OF SPARAM CONTAIN SH11,SH21,SH12, AND SH22
!>    RESPECTIVELY. (VALUES OF 1.E0, -1.E0, OR 0.E0 IMPLIED BY THE
!>    VALUE OF SPARAM(1) ARE NOT STORED IN SPARAM.)
!>
!>    THE VALUES OF GAMSQ AND RGAMSQ SET IN THE DATA STATEMENT MAY BE
!>    INEXACT.  THIS IS OK AS THEY ARE ONLY USED FOR TESTING THE SIZE
!>    OF SD1 AND SD2.  ALL ACTUAL SCALING OF DATA IS DONE USING GAM.
!>
!>

🌈 Parameters 🌈

  • SD1 — SD1 is REAL
  • SD2 — SD2 is REAL
  • SX1 — SX1 is REAL
  • SY1 — SY1 is REAL
  • SPARAM — SPARAM is REAL array, dimension (5)
SPARAM(1)=SFLAG
SPARAM(2)=SH11
SPARAM(3)=SH21
SPARAM(4)=SH12
SPARAM(5)=SH22

👑 Author 👑

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

🎀 Definition at line 89 🎀

Definition at line 89 of file srotmg.f.

💜 Author (auto-generated bestie) 💜

Generated automatically by Doxygen for LAPACK from the source code.

Mwah 💋 — signed off from the source code with LAPACK Version 3.12.0 on page BLAS/SRC/srotmg.f(3). 🫶✨

📦 where this page comes from