BLAS/SRC/drotmg.f(3)       Library Functions Manual       BLAS/SRC/drotmg.f(3)

NAME
       BLAS/SRC/drotmg.f

SYNOPSIS
   Functions/Subroutines
       subroutine drotmg (dd1, dd2, dx1, dy1, dparam)
           DROTMG

Function/Subroutine Documentation
   subroutine drotmg (double precision dd1, double precision dd2, double
       precision dx1, double precision dy1, double precision, dimension(5)
       dparam)
       DROTMG

       Purpose:


               CONSTRUCT THE MODIFIED GIVENS TRANSFORMATION MATRIX H WHICH ZEROS
               THE SECOND COMPONENT OF THE 2-VECTOR  (DSQRT(DD1)*DX1,DSQRT(DD2)*>    DY2)**T.
               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).
               LOCATIONS 2-4 OF DPARAM CONTAIN DH11, DH21, DH12, AND DH22
               RESPECTIVELY. (VALUES OF 1.D0, -1.D0, OR 0.D0 IMPLIED BY THE
               VALUE OF DPARAM(1) ARE NOT STORED IN DPARAM.)

               THE VALUES OF GAMSQ AND RGAMSQ SET IN THE DATA STATEMENT MAY BE
               INEXACT.  THIS IS OK AS THEY ARE ONLY USED FOR TESTING THE SIZE
               OF DD1 AND DD2.  ALL ACTUAL SCALING OF DATA IS DONE USING GAM.

       Parameters
           DD1

                     DD1 is DOUBLE PRECISION

           DD2

                     DD2 is DOUBLE PRECISION

           DX1

                     DX1 is DOUBLE PRECISION

           DY1

                     DY1 is DOUBLE PRECISION

           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 89 of file drotmg.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.

LAPACK                          Version 3.12.0            BLAS/SRC/drotmg.f(3)