anchor.diff:       $            form='formatted',status='old',err=911)
             read(fnc,*,err=911) ic,ang0,ang1
             close(fnc)
  +          ang0 = pi*ang0/180.0
  +          ang1= pi*ang1/180.0
  +          ang0=cos(ang0)
  +          ang1=cos(ang1)
          end if 
  -
   c      ----------------------------
   c      construct relative distances
   c      and bin rdf
  
positive.code:       if(string.eq." ") return
        l  = len_trim(string)
        do i=1,l
         write(13,*) i,string(i:i)
         if(string(i:i).ne." ") exit
        end do
        is_integer = verify(string(i:l), anumber).eq.0
  
negative.code:              ang = SUM(rd*rd1)/(d1*d)
               ocons = ang.ge.ang0
               ocons = ocons.and.(ang.le.ang1)
             end if
             if(d.gt.0.01) k = int(d/dr)+1
             if(k.le.nb.and.ocons ) then
  