anchor.diff:            
             write(unit=lun, fmt=6) U%grid%x(i), &
                  U%data(i,iudens), U%data(i,iumomx), U%data(i,iuener), &
  -               U%data(i,iumomx)/U%data(i,iudens), p, e
  +               U%data(i,iumomx)/U%data(i,iudens), p, e, sqrt(gamma*p/rho)
             
          enddo
   
  
positive.code: 2   format("# time = ", f8.5)
  3   format("# n = ", i4)
  4   format("# nx = ", i4)
  5   format("# ", 7(a16,1x))
  
      write(unit=lun, fmt=1) trim(problem_name)
      write(unit=lun, fmt=2) t
      write(unit=lun, fmt=3) n
      write(unit=lun, fmt=4) U%grid%nx
      write(unit=lun, fmt=5) "x   ", "rho   ", "rho u   ", "rho E   ", "u   ", "p   ", "e   "
  
      ! write out the data
  6   format(2x, 7(g16.10, 1x))
  
      if (write_ghost) then
  
  
negative.code:           
            write(unit=lun, fmt=6) U%grid%x(i), &
                 U%data(i,iudens), U%data(i,iumomx), U%data(i,iuener), &
                 U%data(i,iumomx)/U%data(i,iudens), p, e, sqrt(gamma*p/rho)
            
         enddo
  
  