subroutine vadjust(modvis2)
C
C     C. A. Hummel          7 July 1992     
C
      include 'constnts.inc'
      include 'data.inc'
C
      real*8 modvis2(mxrec,mxfilt)
      real*8 sweight(mxfilt),weight,ratio
      integer*4 firstid,lastid


      firstid=1
      lastid=1
      idate=1
      do ig=1,nfilt
       vis2rat(idate,ig)=0.0D0
       sweight(ig)=0.0D0
      enddo
c
      open(7,file='factors.dat')
c
c     Go through the whole data file and ...
c 
      DO ID=1,NDATA
       do ig=1,nfilt
        if(viserr(id,ig).ne.2)then
        ratio=obsvis2(id,ig)/modvis2(id,ig)
        weight=1.D0/viserr(id,ig)/viserr(id,ig)
     &             *modvis2(id,ig)*modvis2(id,ig)
        vis2rat(idate,ig)=vis2rat(idate,ig)+ratio*weight
        sweight(ig)=sweight(ig)+weight
        endif
       enddo
c
c      ... work on single night, when date or baseline changes
c
       if(date(id+1).ne.date(id).or.baseline(id+1).ne.baseline(id)
     &                          .or.id+1.gt.ndata)then

c      loop over nfilt plots
       do ig=1,nfilt
        if(sweight(ig).ne.0.D0)then
         vis2rat(idate,ig)=vis2rat(idate,ig)/sweight(ig)
        else
         vis2rat(idate,ig)=1.D0
        endif
        do n=1,lastid-firstid+1
         if(viserr(n+firstid-1,ig).ne.2)then
          obsvis2(n+firstid-1,ig)=obsvis2(n+firstid-1,ig)
     &                           /vis2rat(idate,ig)
          viserr(n+firstid-1,ig)=viserr(n+firstid-1,ig)
     &                          /vis2rat(idate,ig)
         endif
        enddo
       enddo      ! End of ig-loop
c
       write(7,*)baseline(id),vis2rat(idate,1),vis2rat(idate,2),
     &                        vis2rat(idate,3)
c
c      Now prepare for the next date
       idate=idate+1
       do ig=1,nfilt
        vis2rat(idate,ig)=0.0D0
        sweight(ig)=0.0D0
       enddo
       firstid=lastid+1
       lastid=firstid-1
c
c     continue here, if date did not change
      endif
      lastid=lastid+1
      ENDDO
      close(7)
      return
      end