LAPACK
3.6.1
LAPACK: Linear Algebra PACKage
|
subroutine drotm | ( | integer | N, |
double precision, dimension(*) | DX, | ||
integer | INCX, | ||
double precision, dimension(*) | DY, | ||
integer | INCY, | ||
double precision, dimension(5) | DPARAM | ||
) |
DROTM
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.
[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 |
Definition at line 100 of file drotm.f.