brent.dem

	PROGRAM D10R3
C	Driver for routine BRENT
	PARAMETER(TOL=1.0E-6,EQL=1.E-4)
	DIMENSION AMIN(20)
	EXTERNAL FUNC
	NMIN=0
	WRITE(*,'(/1X,A)') 'Minima of the function BESSJ0'
	WRITE(*,'(/1X,T6,A,T19,A,T28,A,T40,A/)') 'Min. #','X',
     *		'BESSJ0(X)','BESSJ1(X)'
	DO 12 I=1,100				 
		AX=I
		BX=I+1.0
		CALL MNBRAK(AX,BX,CX,FA,FB,FC,FUNC)
		B=BRENT(AX,BX,CX,FUNC,TOL,XMIN)
		IF (NMIN.EQ.0) THEN
			AMIN(1)=XMIN
			NMIN=1
			WRITE(*,'(1X,5X,I2,3X,3F12.6)') NMIN,XMIN,
     *				BESSJ0(XMIN),BESSJ1(XMIN)
		ELSE
			IFLAG=0
			DO 11 J=1,NMIN
				IF (ABS(XMIN-AMIN(J)).LE.EQL*XMIN)
     *					IFLAG=1
11			CONTINUE
			IF (IFLAG.EQ.0) THEN
				NMIN=NMIN+1
				AMIN(NMIN)=XMIN
				WRITE(*,'(1X,5X,I2,3X,3F12.6)') NMIN,
     *					XMIN,BESSJ0(XMIN),BESSJ1(XMIN)
			ENDIF
		ENDIF
12	CONTINUE
	END

	FUNCTION FUNC(X)
	FUNC=BESSJ0(X)
	RETURN
	END