drotmg (3p)

Name

drotmg - Construct a Gentleman's modified Given's plane rotation

Synopsis

SUBROUTINE DROTMG(D1, D2, B1, B2, PARAM)

DOUBLE PRECISION D1, D2, B1, B2
DOUBLE PRECISION PARAM(*)

SUBROUTINE DROTMG_64(D1, D2, B1, B2, PARAM)

DOUBLE PRECISION D1, D2, B1, B2
DOUBLE PRECISION PARAM(*)




F95 INTERFACE
SUBROUTINE ROTMG(D1, D2, B1, B2, PARAM)

REAL(8) :: D1, D2, B1, B2
REAL(8), DIMENSION(:) :: PARAM

SUBROUTINE ROTMG_64(D1, D2, B1, B2, PARAM)

REAL(8) :: D1, D2, B1, B2
REAL(8), DIMENSION(:) :: PARAM




C INTERFACE
#include <sunperf.h>

void drotmg(double d1, double d2, double b1, double b2, double *param);

void drotmg_64(double d1, double  d2,  double  b1,  double  b2,  double
*param);

Description

Oracle Solaris Studio Performance Library                           drotmg(3P)



NAME
       drotmg - Construct a Gentleman's modified Given's plane rotation


SYNOPSIS
       SUBROUTINE DROTMG(D1, D2, B1, B2, PARAM)

       DOUBLE PRECISION D1, D2, B1, B2
       DOUBLE PRECISION PARAM(*)

       SUBROUTINE DROTMG_64(D1, D2, B1, B2, PARAM)

       DOUBLE PRECISION D1, D2, B1, B2
       DOUBLE PRECISION PARAM(*)




   F95 INTERFACE
       SUBROUTINE ROTMG(D1, D2, B1, B2, PARAM)

       REAL(8) :: D1, D2, B1, B2
       REAL(8), DIMENSION(:) :: PARAM

       SUBROUTINE ROTMG_64(D1, D2, B1, B2, PARAM)

       REAL(8) :: D1, D2, B1, B2
       REAL(8), DIMENSION(:) :: PARAM




   C INTERFACE
       #include <sunperf.h>

       void drotmg(double d1, double d2, double b1, double b2, double *param);

       void drotmg_64(double d1, double  d2,  double  b1,  double  b2,  double
                 *param);



PURPOSE
       drotmg  constructs  the  modified  givens transformation matrix h which
       zeros     the      second      component      of      the      2-vector
       (SQRT(D1)*B1,SQRT(D2)*B2)**T.


ARGUMENTS
       D1 (input/output)
                 On entry, the first diagonal entry in the H matrix.  On exit,
                 changed to reflect the effect of the transformation.


       D2 (input/output)
                 On entry, the second diagonal entry  in  the  H  matrix.   On
                 exit, changed to reflect the effect of the transformation.


       B1 (input/output)
                 On  entry,  the  first  element  of the vector to which the H
                 matrix is applied.  On exit, changed to reflect the effect of
                 the transformation.


       B2 (input)
                 On  entry,  the  second  element of the vector to which the H
                 matrix is applied.  Unchanged on exit.


       PARAM (output)
                 On exit, PARAM(1) describes the form of the  rotation  matrix
                 H, and PARAM(2..5) contain the H matrix.

                 If PARAM(1) = -2 then H = I and no elements of PARAM are mod-
                 ified.

                 If PARAM(1) =  -1  then  PARAM(2)  =  h11,  PARAM(3)  =  h21,
                 PARAM(4) = h12, and PARAM(5) = h22.

                 If  PARAM(1)  =  0  then  h11  = h22 = 1, PARAM(3) = h21, and
                 PARAM(4) = h12.

                 If PARAM(1) = 1 then h12 = 1, h21 = -1, PARAM(2) =  h11,  and
                 PARAM(5) = h22.




                                  7 Nov 2015                        drotmg(3P)