SUBROUTINE MAKEPLOT(MODPLOT)
C Plots observed and model visibility squared versus time with the
C PGPLOT package.  Note that PGPLOT wants REAL*4 reals.
C     J.T. Armstrong      12 March 1991

      INCLUDE 'BINFIT.INC'

      INTEGER*4 MXPOINT,PGBEGIN

      PARAMETER(MXPOINT=100)

      REAL*8 MVIS2(MXPOINT,MXFILT),TMIN,TMAX,T(MXPOINT)
      REAL*8 VMIN(MXFILT),VMAX(MXFILT)

      REAL*4 TIME(2),VISIB(2),DT
      REAL*4 VMIN4(MXFILT),VMAX4(MXFILT),VLOW(MXFILT),VHI(MXFILT)
      REAL*4 TMIN4,TMAX4,TLOW,THI,T4(MXPOINT),V_LO,V_HI,T_LO,T_HI
      REAL*4 MVIS_4(MXPOINT)

      INTEGER*4 IER, DATE, NPLOTS, LENGTH
      LOGICAL*1 MODPLOT, HCOPY, ask
      CHARACTER*4 PLOT_DEV
      CHARACTER*8 PLOTFILE
      CHARACTER*80 TITLE(6)

      COMMON /MOD_VIS/ MVIS2,T,TMIN,TMAX

      EXTERNAL PGBEGIN

      HCOPY = .FALSE.
      PLOTFILE = 'v2   .ps'
      NPLOTS = 0
C Find the minimum and maximum visibilities
      DO IG=1,NFILT
          VMIN(IG)= 0.0
          VMAX(IG)= 0.0
      END DO
    5 DO ID=1,NDATA
          DO IG=1,NFILT
              IF(OBSVIS2(ID,IG).LT.VMIN(IG)) VMIN(IG)=OBSVIS2(ID,IG)
              IF(OBSVIS2(ID,IG).GT.VMAX(IG) 
     1               .AND. OBSVIS2(ID,IG).LT.2.) VMAX(IG)=OBSVIS2(ID,IG)
              IF(MODPLOT) THEN
                  IF(RESID(ID,IG).LT.VMIN(IG)) VMIN(IG)=RESID(ID,IG)
                  IF(RESID(ID,IG).GT.VMAX(IG)
     1               .AND. OBSVIS2(ID,IG).LT.2.) VMAX(IG)=OBSVIS2(ID,IG)
                  IF(MVIS2(ID,IG).LT.VMIN(IG)) VMIN(IG)=MVIS2(ID,IG)
                  IF(MVIS2(ID,IG).GT.VMAX(IG)) VMAX(IG)=MVIS2(ID,IG)
              END IF
              VMIN4(IG)=VMIN(IG)
              VMAX4(IG)=VMAX(IG)
          END DO
      END DO
D     DO IG=1,NFILT
D         WRITE(OUTC,*) ' VMIN, VMAX = ',VMIN(IG),VMAX(IG)
D     END DO
C Start the graphics file
      TMIN4=TMIN
      TMAX4=TMAX
      DT=0.005*(TMAX4-TMIN4)
      DO ID=1,MXPOINT
          T4(ID)=T(ID)
      END DO
   10 IF(HCOPY) THEN
C          WRITE(OUTC,*) ' Making hardcopy'
          IER = PGBEGIN(0,PLOTFILE//PLOT_DEV,1,3)
      ELSE
          IER = PGBEGIN(0,'/EGA',1,1)
      END IF
      IF(IER.NE.1) RETURN
      CALL PGSCF(1)        ! 1=Plain font, 2=Roman, 3=Italic, 4=Script
      CALL PGSCH(1.2)      ! Set character height
C Make the envelope
      ask=.false.
      call pgask(ask)
      DO IG=1,NFILT
          IF(HCOPY) THEN
              CALL PGSLW(2)    ! No. of strokes to draw lines
          ELSE
              CALL PGSLW(1)
          END IF
C         --Write the titles
          WRITE(TITLE(1),'(A,A,I4,A,F4.0,A,I6)')  STARNAME(1:8),
     1      ' = FK ',STARNO,'     ',LAMBDA0(IG),' nm      ',DATE
          WRITE(TITLE(2),'(A,A,A,I2)') 
     1      'Model file:  ',MODDSN(1:14),'    Baseline:  ',BASELINE(1)
          WRITE(TITLE(3),'(A,F7.3,A,F7.3)') 
     1      'Total |gx|u2|d: ',TCHISQ,
     2      '       |gx|u2|d for this filter: ',FCHISQ(IG)
          IF(.NOT.HCOPY) THEN
c             WRITE(OUTC,*) ' Enter comment:'
c             READ(INC,'(A80)') TITLE(3+IG)
              title(3+ig)='                                        '//
     1                    '                                        '
          END IF
         call pgadvance
         CALL PGSCI(5)            ! 1=white 5=cyan
          CALL PGRNGE(TMIN4,TMAX4,TLOW,THI)
          CALL PGRNGE(VMIN4(ig),VMAX4(ig),VLOW(IG),VHI(IG))
          CALL PGVPORT(0.2,0.8,0.3,0.8)
          CALL PGWINDOW(TLOW,THI,VLOW(IG),VHI(IG))
          IF (THI-TLOW.GT.3.) THEN
              CALL PGBOX('A',    1.0,4,'BC',    0.5,5)
              CALL PGBOX('BCNST',1.0,4,'BCNSTV',0.5,5)
          ELSE
              CALL PGBOX('A',    0.5,5,'BC',    0.5,5)
              CALL PGBOX('BCNST',0.5,5,'BCNSTV',0.5,5)
          END IF
C         --Plot the model
          IF(MODPLOT) THEN
              CALL PGSCI(2)
              DO ID=1,MXPOINT
                  MVIS_4(ID)=MVIS2(ID,IG)
              END DO 
              CALL PGLINE(MXPOINT,T4,MVIS_4)
          END IF
C         --Plot the data
          CALL PGSCI(3)
          DO ID=1,NDATA
              IF(OBSVIS2(ID,IG).LT.2.) THEN
                  TIME(1)=HOURS(ID)
                  TIME(2)=HOURS(ID)
                  VISIB(1)=OBSVIS2(ID,IG)+VISERR(ID,IG)
                  VISIB(2)=OBSVIS2(ID,IG)-VISERR(ID,IG)
                  CALL PGLINE(2,TIME,VISIB)
              END IF
          END DO
C         --Plot the residuals offset horizontally a little from the data
          IF(MODPLOT) THEN
              CALL PGSLW(1)
              CALL PGSCI(2)
              DO ID=1,NDATA
                  IF(OBSVIS2(ID,IG).LT.2.) THEN
                      TIME(1)=HOURS(ID)+DT
                      TIME(2)=HOURS(ID)+DT
                      VISIB(1)=RESID(ID,IG)+VISERR(ID,IG)
                      VISIB(2)=RESID(ID,IG)-VISERR(ID,IG)
                      CALL PGLINE(2,TIME,VISIB)
                  END IF
              END DO
          END IF
          CALL PGSCI(1)
          IF (.NOT.HCOPY) CALL PGSLW(1)
C Write the titles
          CALL PGSCH(1.5)
          CALL PGMTEXT('T',2.0, 0,  0,  TITLE(1))
          CALL PGSCH(1.2)
          CALL PGMTEXT('T',1.0, 0,  0,  TITLE(2))
          CALL PGMTEXT('B',5.0, 0,  0,  TITLE(3))
          CALL PGMTEXT('B',7.0, 0,  0,  TITLE(3+IG))
          CALL PGSCI(5)        ! 1=white 5=cyan
          CALL PGMTEXT('L',3.0, 0.5,0.5,'VISIBILITY SQUARED')
          CALL PGMTEXT('B',3.0, 0.5,0.5,'TIME (UT hours)')
          CALL PGSCI(1)        ! 1=white 5=cyan
c          IF(IG.LT.NFILT) CALL PGADVANCE
      END DO
C Close the file
      CALL PGEND
      HCOPY = .FALSE.
   19 IF(QUERY(' Make a hard copy (Y/N)?')) THEN
          HCOPY = .TRUE.
          PLOT_DEV='/vps'
C   20     WRITE(OUTC,*) ' Plot device: '
C          READ(INC,'(A4)') PLOT_DEV
C          IF(PLOT_DEV.EQ.' ') GO TO 20
          NPLOTS = NPLOTS + 1
          WRITE(PLOTFILE(3:5),'(I3.3)') NPLOTS
          WRITE(OUTC,*) ' Creating file ',PLOTFILE//PLOT_DEV,' OK?'
          READ(INC,*) ANSWER
          CALL CAPS(ANSWER)
          IF(ANSWER.NE.'Y') GO TO 19
          GO TO 10
      ELSE IF(QUERY(' Repeat the screen plot? (Y/N)')) THEN
          GO TO 5
      END IF

      RETURN
      END