anchor.diff:      end do
   
       call numerics_d1(this%phi_arr_r(:), this%p_arr_r(:), this%dx)
  -    this%j_arr_r(:) = this%mag_arr_r / this%m * this%p_arr_r(:)
  +    this%j_arr_r(:) = this%mag_arr_r(:) / this%m * this%p_arr_r(:)
   
       call numerics_d2(log(this%mag_arr_r(:)), this%p_var_arr_r(:), &
            this%dx)
  
positive.code:     logical :: sane
      character(:), allocatable :: error_msg
  
      write(*,*) nx, nxl_ext, nxr_ext, nxl_vd, nxr_vd
  
      sane = (nxl_ext .gt. 0) .and. (nxr_ext .gt. 0)
      if (.not. sane) then
         error_msg = "No external region defined in numerical grid; "// &
  
negative.code:     this%p_min = p_min
      this%p_max = p_max
  
      this%dt = dt
  
      this%semi_classical = sc
  