ROTATION METHOD

	READ A(4,4),B(4,4)
	READ 1,N
1	FORMAT(I2)
	READ 2,((A(I,J),J=1,N),I=1,N)
2	FORMAT(4F4.2)
	CALL ROTAT(A,B,N)
	PRINT 3,((B (I_J),J=1,N),I=1,N)
3	FORMAT(//4(3X.4E12.6/))
	STOP
	END


	SUBROUTINE ROTAT(A,B,N)

	DIMENSION A(N,N), B(N,N)
	DO 1 I=1,N
	DO 1 J=1,N
1	B(I,J)=A(I,J)
	N1=N-1
	DO 2 I=1,N1
	I1=I+1
	IF(A(I,I).NE.0) GO TO 4
	DO 3 J=I1,N
	B(I,J)=-A(J,J)
3	B(J,I)=0
	GO TO 2
4	DO 6 J=I1,N
	Q=-A(J,I)/A(I,I)
	T=SORT(1+Q+Q)
	B(I,J)=A(I,J)/T-A(J,J)*Q/T
6	B(J,I=0)
2	CONTINUE
	RETURN
	END