SUBROUTINE PLTSEG
      REAL*4    XFAC,XOFF
      INTEGER*2 XTYPE,XMAXB,XSMINB,XSMAXB,XSNOWB
      COMMON/VXDES/XFAC,XOFF,XTYPE,XMAXB,XSMINB,XSMAXB,XSNOWB
      REAL*4    XAFDU,XADDU,XADDB
      INTEGER*2 XAFDB,XANDB,XAIND,XAGRID,XANGB,XAING,XATICK,XANTB,XAINT
      COMMON/VXADES/XAFDU,XADDU,XADDB,XAFDB,XANDB,XAIND ,
     1              XAGRID,XANGB,XAING,XATICK,XANTB,XAINT
      INTEGER*2 XTA,XTL,XTOFFB,XTIND
      COMMON/VXTDES/XTA,XTL,XTOFFB,XTIND
      REAL*4    YFAC,YOFF
      INTEGER*2 YTYPE,YMINB,YMAXB
      COMMON/VYDES/YFAC,YOFF,YTYPE,YMINB,YMAXB
      REAL*4    YAFDU,YADDU,YADDB
      INTEGER*2 YAFDB,YAGRID,YATICK
      COMMON/VYADES/YAFDU,YADDU,YADDB,YAFDB,YAGRID,YATICK
      INTEGER*2 AMAX,ALAST,ALEN,A
      COMMON/VADES/AMAX,ALAST,ALEN,A(2)
      INTEGER*2 ANPTS,ATYPE,AXA,AXF,AXI,AXMIN,ADELX
      INTEGER*2 AYA,AYF,AYI,AEA,AJOIN,AOFF
      INTEGER*2 AXP,AYP,AEP,AXC,AYC,AEC,AXN,AYN,AEN,AIC
      COMMON/VAOFF/ANPTS,ATYPE,AXA,AXF,AXI,AYA,AYF,AYI,AEA,AJOIN,AOFF,
     1             AXP,AYP,AEP,AXC,AYC,AEC,AXN,AYN,AEN,AIC
      EQUIVALENCE (AXA,AXMIN),(AXF,ADELX)
      INTEGER*2 PSPP,PBUFL,PCY,PCYSPP,PBY,POFBY
      REAL*4 PBPIY,PBPCY,PBPIX
      COMMON/VPDP/PSPP,PBUFL,PCY,PCYSPP,PBY,POFBY,PBPIY,PBPCY,PBPIX
      LOGICAL*1 PNTBUF(2),PLTBUF(2),PLTYGB(2)
      INTEGER*2 RPSPP
      COMMON/VPNTBF/RPSPP,PNTBUF
      COMMON/VPLTBF/PLTBUF
      COMMON/VPLTYG/PLTYGB
      INTEGER*2 ABORT
      COMMON/VABORT/ABORT
      INTEGER*2 XL,YL,XH,YH,YPL,YPH
      INTEGER*2 IC
      LOGICAL*1 C(2)
      EQUIVALENCE (IC,C(1))
      CALL VSINIT
      IF(XSMAXB.LT.XSMINB)GO TO 5000
      DO 4000 XSNOWB=XSMINB,XSMAXB
      IF(ABORT.NE.0)RETURN
      IF(YAGRID.EQ.0)GO TO 2020
      IF((XSNOWB/2)*2.NE.XSNOWB)GO TO 2020
      CALL VIPLTB(PLTYGB)
      GO TO 2035
2020  CALL VIPLTB
2035  CALL VSBSET(YMINB)
      CALL VSBSET(YMAXB)
      IF((XSNOWB.GT.0).AND.(XSNOWB.NE.XMAXB))GO TO 2040
      CALL VBSET(YMINB,YMAXB)
2040  IF((XANDB.EQ.XSNOWB).OR.
     1 ((XTA.NE.0).AND.(XTIND.LT.XTL).AND.(XTOFFB.LE.XSNOWB)
     2 .AND.(RPSPP.EQ.0)))CALL VXLAB
      IF(XANGB.EQ.XSNOWB)CALL VXGRID
      IF(XANTB.EQ.XSNOWB)CALL VXTICK
      IF(ALAST.LT.0)GO TO 4000
      DO 3000 IOFF=0,ALAST,ALEN
      IF(A(IOFF+AXC).LE.(XSNOWB+2))CALL VPSYM(A(IOFF+1))
      IC=A(IOFF+AJOIN)
      IJOIN=C(2)
      ICHR=C(1)
      IF(IJOIN.EQ.0)GO TO 3000
      XL=A(IOFF+AXP)
      YL=A(IOFF+AYP)
      XH=A(IOFF+AXC)
      YH=A(IOFF+AYC)
      ITIME=1
2100  IF((XSNOWB.LT.XL).OR.(XH.EQ.32767))GO TO 2900
      IF(IJOIN.EQ.2)GO TO 2200
      CALL VCNCT(XL,YL,XH,YH,YPL,YPH)
      GO TO 2300
CHISTOGRAM PLOT
2200  IF(XSNOWB-XH)2205,2210,2220
2205  YPL=YL
      YPH=YL
      GO TO 2300
2210  YPL=YL
      YPH=YH
      IF(YPL.LE.YPH)GO TO 2300
      IT=YPL
      YPL=YPH
      YPH=IT
      GO TO 2300
2220  YPL=YH
      YPH=YH
2300  CONTINUE
CGET POINTS TO BE IN RANGE
      IYL=YL
      IYH=YH
      IF(IYL.LE.IYH)GO TO 2310
      IT=IYL
      IYL=IYH
      IYH=IT
2310  INC=0
      IF(ICHR.EQ.0)GO TO 2320
      IF((XSNOWB.GE.(XL-2)).AND.(XSNOWB.LE.(XL+2)))INC=3
      IF((XSNOWB.GE.(XH-2)).AND.(XSNOWB.LE.(XH+2)))INC=3
2320  IF(YPL.LT.(IYL+INC))YPL=IYL+INC
      IF(YPH.GT.(IYH-INC))YPH=IYH-INC
      IF(YPL.LT.YMINB)YPL=YMINB
      IF(YPH.GT.YMAXB)YPH=YMAXB
      IF(YPL.GT.YPH)GO TO 2900
      IF(YPL.NE.YPH)GO TO 2400
      CALL VSBSET(YPL)
      GO TO 2900
2400  CALL VBSET(YPL,YPH)
2900  IF(XH.GT.XSNOWB) GO TO 3000
      IF(ITIME.EQ.2)GO TO 2910
      ITIME=2
      XL=A(IOFF+AXC)
      YL=A(IOFF+AYC)
      XH=A(IOFF+AXN)
      YH=A(IOFF+AYN)
      ID=A(IOFF+AIC)+1
      GO TO 2100
2910  IF(ID.GT.A(IOFF+ANPTS))GO TO 3000
      XL=XH
      YL=YH
      ID=ID+1
      CALL VGETXY(A(IOFF+1),ID,XH,YH,IDUM)
      GO TO 2100
3000  CONTINUE
4000  CALL VPLT
      XSMINB=XSMAXB+1
5000  ALAST=-ALEN
      RETURN
      END