---

C Library Functions  - drotm (3)

---

NAME

drotm(3f) - [BLAS:SINGLE_BLAS_LEVEL1] Apply the Modified Givens Transformation, H, to the 2 by N matrix

CONTENTS

Synopsis
Definition
Options
Authors
See Also

SYNOPSIS

subroutine drotm(n,dx,incx,dy,incy,dparam)

      .. Scalar Arguments ..
      integer,intent(in)             :: incx,incy,n
      ..
      .. Array Arguments ..
      double precision,intent(in)    :: dparam(5)
      double precision,intent(inout) :: dx(*),dy(*)
      ..

DEFINITION

Apply the Modified Givens Transformation, H, to the 2 by N matrix

(DX**T) , where **T indicates transpose. the elements of DX are in (DY**T)

DX(LX+I*INCX), I = 0 to N-1, where LX = 1 if INCX .ge. 0, else LX = (-INCX)*N, and similarly for SY using LY and INCY. with DPARAM(1)=DFLAG, H has one of the following forms..

       DFLAG=-1.D0     DFLAG=0.D0        DFLAG=1.D0     DFLAG=-2.D0

         (DH11  DH12)    (1.D0  DH12)    (DH11  1.D0)    (1.D0  0.D0)
       H=(          )    (          )    (          )    (          )
         (DH21  DH22),   (DH21  1.D0),   (-1.D0 DH22),   (0.D0  1.D0).

SEE DROTMG FOR A DESCRIPTION OF DATA STORAGE IN DPARAM.

OPTIONS

    N

number of elements in input vector(s)

    DX

DX is DOUBLE PRECISION array, dimension ( 1 + ( N - 1 )*abs( INCX ) )

    INCX

storage spacing between elements of DX

    DY

DY is DOUBLE PRECISION array, dimension ( 1 + ( N - 1 )*abs( INCY ) )

    INCY

storage spacing between elements of DY

    DPARAM

array, dimension (5)

           DPARAM(1)=DFLAG
           DPARAM(2)=DH11
           DPARAM(3)=DH21
           DPARAM(4)=DH12
           DPARAM(5)=DH22

AUTHORS

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

 date:November 2017

 \ingroup double_blas_level1

SEE ALSO

Online html documentation available at http://www.netlib.org/lapack/explore-html/

---

Nemo Release 3.1

drotm (3)

February 23, 2025

Generated by manServer 1.08 from 669bda20-1960-4692-b3ff-7ef37467b70d using man macros.