
def default_preferences():
    return dict(show_a_ion=0,
                show_b_ion=1,
                show_c_ion=0,
                show_x_ion=0,
                show_y_ion=1,
                show_z_ion=0,
                ms2_tolerance=0.3,
                ms2_tolerance_unit = "Da",
                max_isotope=2,
                add_losses=0,
                add_isotopes=0,
                ms1_tolerance=50,
                ms1_tolerance_unit = "ppm",
                )
