NAME

drotg - Construct a Given’s plane rotation

SYNOPSIS

SUBROUTINE DROTG (A, B, C, S)

void drotg(double ∗da, double ∗db, double ∗dc,
double ∗s)

DOUBLE PRECISION    A, B, C, S

PURPOSE

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

PARAMETERS

A      - DOUBLE PRECISION. 
On entry, A contains the entry in the first vector that corresponds to the element to be annihilated in the second vector. Unchanged on exit.

B      - DOUBLE PRECISION. 
On entry, B contains the entry to be annihilated in the second vector. Unchanged on exit.

C, S   - DOUBLE PRECISION. 
On exit, C and S are the elements of the rotation matrix that will be applied to annihilate B.

Sun, Inc.  —  Last change: 20 Sep 1996