anchor.diff:        endif
   C If output file unspecified, print result to standard output
         if (ofile.eq.'none'.and.p.eq.0) p = 1
  +C If clip file is defined, read it
  +      if (clip.ne.'none') then
  +          open(unit=201,file=clip,status='old')
  +          i = 1
  + 1001     read(201,*,end=1002) xx(i),yy(i)
  +              i = i + 1
  +              goto 1001
  + 1002     continue
  +          nn = i - 1
  +      endif
   
   C----
   C Calculate number of points and grid increments
  
positive.code:       END
  
  C----------------------------------------------------------------------C
  
        SUBROUTINE gcmdln(x1,x2,nx,dx,y1,y2,ny,dy,z,ofile,p,ref,xsec,xz)
        IMPLICIT none
        CHARACTER*40 tag,ofile
        REAL*8 x1,x2,y1,y2,z,dx,dy,ref(5)
        INTEGER narg,i,j,nx,ny,p,xsec,xz
  C Initialize variable values
  
negative.code:           i = i + 3
        elseif (tag(1:3).eq.'-xz') then
            xz = 1
        elseif (tag(1:5).eq.'-clip') then
            i = i + 1
            call getarg(i,clip)
        elseif (tag(1:2).eq.'-x') then
            i = i + 1
            call getarg(i,tag)
  