anchor.diff:  ! ================================================ !
   ! Read in command line arguments and initialize    !
   ! ================================================ !
  -
  -! ===================================== !
  -! Allocate all arrays in the modules    !
  -! ===================================== !
   subroutine init
     use state
     use constants
  
positive.code: 
    call init
  
    do while (time .lt. tfin)
      if(iter .gt. itermax) then
        print*, "Exceeded maximum iterations. Exiting..."
        stop
  
negative.code:     call step
      time = time + dt
  
      if(mod(itermax,10) .eq. 0) then
        print*,"Iteration: ",iter," Time: ",time
        print*,"Max U: ", maxval(vx(:))," Max V: ",maxval(vy(:))," Max W: ",maxval(vz(:))
        print*,"  "
      end if
  
    end do
  
    call deinit
  