	SUBROUTINE SPGET(N,X,F,Y,EL,AX,AF,APR,ADPF)
C
C	THE SUBROUTINES IN THIS FILE ARE TAKEN FROM
C	A PAPER BY R.F. DAVIS, "SPLINE CURVE FIT FUNCTIONS,
C	THEIR DERIVATION AND USE"
C	JULY 23, 1968
C
	DIMENSION X(1),Y(1),F(1),EL(1)
	K=2
84	IF(AX-X(K))83,83,85
85	IF(AX-X(N))87,87,88
87	K=K+1
	GOTO 84
88	K=N
83	KK=K-1
	FF=Y(KK)*(X(K)-AX)**3/(6.*EL(K))+Y(K)*(AX-X(KK))**3/(6.*EL(K))
	AF=FF+(F(K)/EL(K)-Y(K)*EL(K)/6.0)*(AX-X(KK))
	BF=(F(KK)/EL(K)-Y(KK)*EL(K)/6.0)*(X(K)-AX)
	AF=AF+BF
	BF=Y(K)*(AX-X(KK))**2/(2.*EL(K))-Y(KK)*(X(K)-AX)**2/(2.*EL(K))
	BF=BF+(F(K)-F(KK))/EL(K)-EL(K)*(Y(K)-Y(KK))/6.0
	APF=BF
	BF=Y(KK)*(X(K)-AX)/EL(K)+Y(K)*(AX-X(KK))/EL(K)
	ADPF=BF
	RETURN
	END
	SUBROUTINE SPFIT(N,X,F,Y,EL,A,B,C)
	DIMENSION X(1),Y(1),F(1),EL(1),A(1),B(1),C(1)
	JJ=N-1
	MM=N-2
	KK=N-3
	DO 1 I=1,JJ
	K=I+1
1	EL(K)=X(K)-X(I)
	DO 2 I=1,MM
	Y(I)=(F(I+2)-F(I+1))/EL(I+2)-(F(I+1)-F(I))/EL(I+1)
	B(I)=(EL(I+1)+EL(I+2))/3.0
	A(I)=EL(I+1)/6.0
2	C(I)=EL(I+2)/6.0
	C(1)=C(1)/B(1)
	DO 3 I=2,MM
	B(I)=B(I)-A(I)*C(I-1)
3	C(I)=C(I)/B(I)
	B(1)=Y(1)/B(1)
	DO 4 I=2,MM
4	B(I)=(Y(I)-A(I)*B(I-1))/B(I)
	Y(MM)=B(MM)
	K=KK
	DO 5 I=2,MM
	Y(K)=B(K)-C(K)*Y(K+1)
5	K=K-1
	K=JJ
	DO 6 I=1,MM
	Y(K)=Y(K-1)
6	K=K-1
	Y(1)=0.0
	Y(N)=0.0
	RETURN
	END
