write_fields Subroutine

  subroutine write_fields(gnostics)
    use fields_arrays, only: phinew, aparnew, bparnew
    use run_parameters, only: has_phi, has_apar, has_bpar
    use diagnostics_config, only: diagnostics_type
    use gs2_io, only: nc_write_field
    implicit none
    type(diagnostics_type), intent(inout) :: gnostics

    if (.not. gnostics%writing) return

    if (has_phi) then
      call nc_write_field(gnostics%file_id, gnostics%nout, phinew, &
           "phi", "Electrostatic potential", gnostics%igomega, gnostics%write_phi_over_time,&
           gnostics%current_results%phi2)
    end if

    if (has_apar) then
      call nc_write_field(gnostics%file_id, gnostics%nout, aparnew, &
           "apar", "Parallel magnetic potential", gnostics%igomega, gnostics%write_apar_over_time,&
           gnostics%current_results%apar2)
    end if

    if (has_bpar) then
      call nc_write_field(gnostics%file_id, gnostics%nout, bparnew, &
           "bpar", "Parallel magnetic field", gnostics%igomega, gnostics%write_bpar_over_time,&
           gnostics%current_results%bpar2)
    end if
  end subroutine write_fields