srotmg.f(3)

srotmg.f3

Usage

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:

!>
!>    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 of file srotmg.f.

Releases

2 releases since Debian 9 (Stretch); the text changed 1 time.

  1. 9
  2. Arch

Author

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From lapack-doc 3.12.1-2 in Arch Linux 2026-11-01. Parsed by carta from the page's man source.