SUBROUTINE VISWS (EF,Z,J1,J2,NP,I1,I2,NT,L,M,B,O,PR,PL)

C	WATERLEVEL SEQUENCE
C	L=1  WESTERN VIEW, L=-1  EASTERN VIEW
C	M=1  SOUTHERN VIEW, M=-1  NORTHERN VIEW
C	
	EXTERNAL PR,PL
	LOGICAL B
	DIMENSION EF(1),O(3,3)
	DIMENSION AZ(201),R1(201),R2(201)
	DIMENSION	AW(501),RW(501)
	DATA MA,MK /501,201/

	IX(J,I)=(I-1)*NP+MOD(NP+J-1,NP)+1

	N=L*M
	EL=FLOAT(L)
	EM=FLOAT(M)
	DP=6.28318/FLOAT(NP)
	DT=3.14149/FLOAT(NT)
	HT=0.5*DT

	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=HT+DT*FLOAT(I-1)
	P=DP*FLOAT(J-1)
 20	IF((I.GT.I2).OR.(I.LT.I1)) GOTO 22
	K=MAX0(MIN0(K+N,MK),1)
	CALL PR (R1(K),AZ(K),EF(IX(J,I)),T,P,O)
	CALL PR (R2(K),AZ(K),Z,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 PR (R1(K),AZ(K),EF(IX(J,I)),T,P,O)
	CALL PR (R2(K),AZ(K),Z,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)
 31	R2(MM)=R2(K+MM-1)
	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)
 37	R2(K-MM+1)=TE
 38	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 (AW,RW,NW,MA,AZ(K1),R1(K1),KK,AZ(K1),R2(K1),KK,-1.0)
	CALL VISHO (AW,RW,NW,1,PL)
	CALL VISHO (AZ(K1),R1(K1),KK,-1,PL)

 50	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