SROTMG(1)

NAME
LAPACK-3 - CONSTRUCT THE MODIFIED GIVENS TRANSFORMATION MATRIX H WHICH ZEROS THE SECOND COMPONENT OF THE 2-VECTOR (SQRT(SD1)*SX1,SQRT(SD2)*

SYNOPSIS

SUBROUTINE SROTMG(SD1,SD2,SX1,SY1,SPARAM)

REAL
    SD1,SD2,SX1,SY1

REAL
    SPARAM(5)

PURPOSE
   CONSTRUCT THE MODIFIED GIVENS TRANSFORMATION MATRIX H WHICH ZEROS
   THE SECOND COMPONENT OF THE 2-VECTOR (SQRT(SD1)*SX1,SQRT(SD2)*
    SY2)**T.
    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).
    LOCATIONS 2-4 OF SPARAM CONTAIN SH11,SH21,SH12, AND SH22
    RESPECTIVELY. (VALUES OF 1.E0, -1.E0, OR 0.E0 IMPLIED BY THE
    VALUE OF SPARAM(1) ARE NOT STORED IN SPARAM.)
    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 SD1 AND SD2. ALL ACTUAL SCALING OF DATA IS DONE USING GAM.

ARGUMENTS

SD1    (input/output) REAL

SD2    (input/output) REAL

SX1    (input/output) REAL

SY1    (input) REAL
     SPARAM (input/output) REAL array, dimension 5
     SPARAM(1)=SFLAG
     SPARAM(2)=SH11
     SPARAM(3)=SH21
     SPARAM(4)=SH12
     SPARAM(5)=SH22