NAME

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

SYNOPSIS

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

void drotmg(double ∗dd1, double ∗dd2, double ∗db1,
double ∗db2, double ∗dparam)

DOUBLE PRECISION    B1, B2, D1, D2, PARAM(5)

PURPOSE

SROTMG - Construct Gentleman’s modified a Given’s plane rotation that will annihilate an element of a vector. 
 

PARAMETERS

D1     - DOUBLE PRECISION. 
On entry, the first diagonal entry in the H matrix.  On exit, changed to reflect the effect of the transformation.

D2     - DOUBLE PRECISION. 
On entry, the second diagonal entry in the H matrix.  On exit, changed to reflect the effect of the transformation.

B1     - DOUBLE PRECISION. 
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     - DOUBLE PRECISION. 
On entry, the second element of the vector to which the H matrix is applied. On exit, changed to reflect the effect of the transformation.

PARAM  - DOUBLE PRECISION. 
On entry, PARAM(1) describes the form of the H matrix.  On exit, PARAM(2..5) contain the H matrix.

Sun, Inc.  —  Last change: 20 Sep 1996