dlartgp.f(3)

dlartgp.f3

Usage

Functions/Subroutines

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

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.

Purpose:

!>
!> DLARTGP generates a plane rotation so that
!>
!>    [  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.
!>
!>  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.

Releases

4 releases since Debian 7 (Wheezy); the text changed 3 times.

  1. 7
  2. 8
  3. 9
  4. Arch

Author

Generated automatically by Doxygen for LAPACK from the source code.

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