rotm - Man Page

subroutine drotm (n, dx, incx, dy, incy, dparam)
DROTM
subroutine srotm (n, sx, incx, sy, incy, sparam)
SROTM

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

N

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

DX

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

INCX

          INCX is INTEGER
         storage spacing between elements of DX

DY

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

INCY

          INCY is INTEGER
         storage spacing between elements of DY

DPARAM

          DPARAM is DOUBLE PRECISION array, dimension (5)
     DPARAM(1)=DFLAG
     DPARAM(2)=DH11
     DPARAM(3)=DH21
     DPARAM(4)=DH12
     DPARAM(5)=DH22

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line 95 of file drotm.f.

SROTM

Purpose:

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

    (SX**T) , WHERE **T INDICATES TRANSPOSE. THE ELEMENTS OF SX ARE IN
    (SX**T)

    SX(LX+I*INCX), I = 0 TO N-1, WHERE LX = 1 IF INCX .GE. 0, ELSE
    LX = (-INCX)*N, AND SIMILARLY FOR SY USING USING LY AND INCY.
    WITH SPARAM(1)=SFLAG, H HAS ONE OF THE FOLLOWING FORMS..

    SFLAG=-1.E0     SFLAG=0.E0        SFLAG=1.E0     SFLAG=-2.E0

      (SH11  SH12)    (1.E0  SH12)    (SH11  1.E0)    (1.E0  0.E0)
    H=(          )    (          )    (          )    (          )
      (SH21  SH22),   (SH21  1.E0),   (-1.E0 SH22),   (0.E0  1.E0).
    SEE  SROTMG FOR A DESCRIPTION OF DATA STORAGE IN SPARAM.

Parameters

N

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

SX

          SX is REAL array, dimension ( 1 + ( N - 1 )*abs( INCX ) )

INCX

          INCX is INTEGER
         storage spacing between elements of SX

SY

          SY is REAL array, dimension ( 1 + ( N - 1 )*abs( INCY ) )

INCY

          INCY is INTEGER
         storage spacing between elements of SY

SPARAM

          SPARAM is REAL array, dimension (5)
     SPARAM(1)=SFLAG
     SPARAM(2)=SH11
     SPARAM(3)=SH21
     SPARAM(4)=SH12
     SPARAM(5)=SH22

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line 96 of file srotm.f.