DROTM(1)

NAME
LAPACK-3 - APPLY THE MODIFIED GIVENS TRANSFORMATION, H, TO THE 2 BY N MATRIX (DX**T) , WHERE **T INDICATES TRANSPOSE

SYNOPSIS

SUBROUTINE DROTM(N,DX,INCX,DY,INCY,DPARAM)

INTEGER
    INCX,INCY,N

DOUBLE
    PRECISION DPARAM(5),DX(*),DY(*)

PURPOSE
   APPLY THE MODIFIED GIVENS TRANSFORMATION, H, TO THE 2 BY N MATRIX
    (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.

ARGUMENTS

N      (input) INTEGER
     number of elements in input vector(s)

DX     (input/output) DOUBLE PRECISION array, dimension N
     double precision vector with N elements

INCX   (input) INTEGER
     storage spacing between elements of DX

DY     (input/output) DOUBLE PRECISION array, dimension N
     double precision vector with N elements

INCY   (input) INTEGER
     storage spacing between elements of DY
     DPARAM (input/output) DOUBLE PRECISION array, dimension 5
     DPARAM(1)=DFLAG
     DPARAM(2)=DH11
     DPARAM(3)=DH21
     DPARAM(4)=DH12
     DPARAM(5)=DH22