PROGRAM D9R13
C	Driver for routine MNEWT
	PARAMETER(NTRIAL=5,TOLX=1.0E-6,N=4,TOLF=1.0E-6,NP=15)
	DIMENSION X(NP),ALPHA(NP,NP),BETA(NP)
	DO 15 KK=-1,1,2
		DO 14 K=1,3
			XX=0.2*K*KK
			WRITE(*,'(/1X,A,I2)') 'Starting vector number',K
			DO 11 I=1,4
				X(I)=XX+0.2*I
				WRITE(*,'(1X,T5,A,I1,A,F5.2)')'X(',I,') = ',X(I)
11			CONTINUE
			DO 13 J=1,NTRIAL
				CALL MNEWT(1,X,N,TOLX,TOLF)
				CALL USRFUN(X,ALPHA,BETA)
				WRITE(*,'(/1X,T5,A,T14,A,T29,A/)')'I','X(I)','F'
				DO 12 I=1,N
					WRITE(*,'(1X,I4,2E15.6)')I,X(I),-BETA(I)
12				CONTINUE
				WRITE(*,'(/1X,A)') 'press RETURN to continue...'
				READ(*,*)
13			CONTINUE
14		CONTINUE
15	CONTINUE
	END

	SUBROUTINE USRFUN(X,ALPHA,BETA)
	PARAMETER(NP=15)
	DIMENSION ALPHA(NP,NP),BETA(NP),X(NP)
	ALPHA(1,1)=-2.0*X(1)
	ALPHA(1,2)=-2.0*X(2)
	ALPHA(1,3)=-2.0*X(3)
	ALPHA(1,4)=1.0
	ALPHA(2,1)=2.0*X(1)
	ALPHA(2,2)=2.0*X(2)
	ALPHA(2,3)=2.0*X(3)
	ALPHA(2,4)=2.0*X(4)
	ALPHA(3,1)=1.0
	ALPHA(3,2)=-1.0
	ALPHA(3,3)=0.0
	ALPHA(3,4)=0.0
	ALPHA(4,1)=0.0
	ALPHA(4,2)=1.0
	ALPHA(4,3)=-1.0
	ALPHA(4,4)=0.0
	BETA(1)=X(1)**2+X(2)**2+X(3)**2-X(4)
	BETA(2)=-X(1)**2-X(2)**2-X(3)**2-X(4)**2+1.0
	BETA(3)=-X(1)+X(2)
	BETA(4)=-X(2)+X(3)
	END