hdfpbs.for

DFPBFS方法源代码

	SUBROUTINE HDFPBS(H,N,DELG,DELX,IE)
	DIMENSION H(20,20),DELX(20),DELG(20),HDG(20),DHG(20),DGH(20)
	DGHDG=0.0
	DXDG=0.0
	DO 10 I=1,N
	HDG(I)=0.0
	DO 11 J=1,N
11	HDG(I)=HDG(I)+H(I,J)*DELG(J)
	DGHDG=DGHDG+DELG(I)*HDG(I)
10	DXDG=DXDG+DELX(I)*DELG(I)
	IE=-1
	IF(ABS(DXDG).LT.0.1E-60) GO TO 40
	IF(DGHDG.LT.0.1E-60) GO TO 40
	IE=0
	IF(DXDG.LT.DGHDG) GO TO 50
	A=1.0+DGHDG/DXDG
	DO 30 I=1,N
	DO 30 J=1,N
30	H(I,J)=H(I,J)+((A*DELX(I)-HDG(I))*DELX(J)-DELX(I)*HDG(J))/DXDG
	GO TO 40
50	DO 60 I=1,N
	DHG(I)=0.0
	DGH(I)=0.0
	DO 70 J=1,N
	DHG(I)=DHG(I)-H(I,J)*DELG(J)
70	DGH(I)=DGH(I)+DELG(J)*H(J,I)
60	CONTINUE
	DO 80 I=1,N
	DO 80 J=1,N
80	H(I,J)=H(I,J)+DELX(I)*DELX(J)/DXDG+DHG(I)*DGH(J)/DGHDG
40	RETURN
	END