SUBROUTINE VISOS(F1,F2,J1,J2,NP,I1,I2,NT,L,M,S,B,O,PL)
C	[OUTER SEQUENCE]
C	L=1 WESTERN VIEW, L=-1 EASTERN VIEW
C	M=1 SOUTHERN VIEW, M=-1 NORTHERN VIEW
C	[02-JUN-74]
C	COPIED FROM DECUS
C	[STEIGER 20-DEC-75]
	EXTERNAL PL
	LOGICAL B
	DIMENSION F1(1),F2(1),O(3,3)
	DIMENSION AZ(201),R1(201),R2(201)
	DIMENSION PO(501),RO(501)
	DATA MA,MK/501,201/
	IX(J,I)=(I-1)*NP+MOD(NP+J-1,NP)+1
	N=L*M
	NN=1
	EL=FLOAT(L)
	EM=FLOAT(M)
	DP=6.28318/FLOAT(NP)
	DT=3.14159/FLOAT(NT)
	CALL VISNP(PH,TH,JP,IT,NP,NT,O)
	I0=((I1+I2)+M*(I1-I2))/2+M
	J0=((J1+J2)+L*(J1-J2))/2
	K0=((MK+1)*(1-N))/2
10	K=K0
	I=MAX0(MIN0(I0,I2+1),I1-1)
	J=J0
	T=TH+DT*FLOAT(I-IT)
	P=PH+DP*FLOAT(J-JP)
20	IF((I.GT.I2).OR.(I.LT.I1)) GOTO 22
	K=MAX0(MIN0(K+N,MK),1)
	CALL VISSP(R1(K),AZ(K),F1(IX(J,I)),T,P,O)
	CALL VISSP(R2(K),AZ(K),F2(IX(J,I)),T,P,O)
22	I=I-M
	T=T-EM*DT
	IF((I.GT.I2).OR.(I.LT.I1)) GOTO 30
	K=MAX0(MIN0(K+N,MK),1)
	CALL VISSP(R1(K),AZ(K),F1(IX(J,I)),T,P,O)
	CALL VISSP(R1(K),AZ(K),F2(IX(J,I)),T,P,O)
	J=J+L
	P=P+EL*DP
	IF((J.LE.J2).AND.(J.GE.J1)) GOTO 20
30	IF(N.GT.0) GOTO 32
	M1=MK-K+1
	DO 31 MM=1,M1
	AZ(MM)=AZ(K+MM-1)
	R1(MM)=R1(K+MM-1)
	R2(MM)=R2(K+MM-1)
31	CONTINUE
	K=M1
32	IF(B) GOTO 36
	DO 35 MM=1,K
35	IF(AZ(MM).LT.0.0) AZ(MM)=AZ(MM)+1.0
36	IF(AZ(1).LE.AZ(K)) GOTO 38
	DO 37 MM=1,K
	TE=AZ(MM)
	AZ(MM)=AZ(K-MM+1)
	AZ(K-MM+1)=TE
	TE=R1(MM)
	R1(MM)=R1(K-MM+1)
	R1(K-MM+1)=TE
	TE=R2(MM)
	R2(MM)=R2(K-MM+1)
	R2(K-MM+1)=TE
37	CONTINUE
38	CONTINUE
	K1=1
	IF(K.LE.2) GOTO 40
	DO 39 MM=3,K
	K1=MM-2
39	IF((AZ(MM-2).LE.AZ(MM-1)).AND.(AZ(MM-1).LE.AZ(MM))) GOTO 40
	K1=K-1
40	K3=K1+2
	K2=K1
	IF(K3.LE.2) GOTO 42
	IF(K3.GT.K) GOTO 42
	IF(K.LE.2) GOTO 42
	DO 41 MM=K3,K
	K2=MM-1
41	IF(AZ(MM-1).GT.AZ(MM)) GOTO 42
	K2=K
42	IF(K2.LE.1) GOTO 50
	IF(K2-K1+1.LE.1) GOTO 50
	KK=K2-K1+1
	CALL VISRB(PO,RO,NO,MA,AZ(K1),R1(K1),KK,AZ(K1),R2(K1),KK,S)
	CALL VISHO(PO,RO,NO,NN,PL)
50	NN=-NN
	I0=I0+M
	IF((I0.GE.I1-1).AND.(I0.LE.I2+1)) GOTO 10
	J0=J0+L
	IF((J0.GE.J1).AND.(J0.LE.J2)) GOTO 10
	RETURN
	END