LAPACK  3.5.0 LAPACK: Linear Algebra PACKage
drotm.f File Reference

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## Functions/Subroutines

subroutine drotm (N, DX, INCX, DY, INCY, DPARAM)
DROTM More...

## Function/Subroutine Documentation

 subroutine drotm ( integer N, double precision, dimension(*) DX, integer INCX, double precision, dimension(*) DY, integer INCY, double precision, dimension(5) DPARAM )

DROTM

Purpose:
```    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.```
Parameters
 [in] N ``` N is INTEGER number of elements in input vector(s)``` [in,out] DX ``` DX is DOUBLE PRECISION array, dimension N double precision vector with N elements``` [in] INCX ``` INCX is INTEGER storage spacing between elements of DX``` [in,out] DY ``` DY is DOUBLE PRECISION array, dimension N double precision vector with N elements``` [in] INCY ``` INCY is INTEGER storage spacing between elements of DY``` [in,out] DPARAM ``` DPARAM is DOUBLE PRECISION array, dimension 5 DPARAM(1)=DFLAG DPARAM(2)=DH11 DPARAM(3)=DH21 DPARAM(4)=DH12 DPARAM(5)=DH22```
Date
November 2011

Definition at line 99 of file drotm.f.

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