Dear Matthew, I print all the attributes of a ParticlePhasePlot by calling, it seems .x and .y and [] are not included: ['__abstractmethods__', '__annotations__', '__class__', '__delattr__', '__dict__', '__dir__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__getitem__', '__gt__', '__hash__', '__init__', '__init_subclass__', '__le__', '__lt__', '__module__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__slots__', '__str__', '__subclasshook__', '__weakref__', '_abc_impl', '_callbacks', '_colorbar_label', '_colorbar_valid', '_default_figure_size', '_default_font_size', '_font_color', '_font_properties', '_get_axes_labels', '_get_axes_unit_labels', '_get_default_handlers', '_get_field_label', '_get_field_log', '_get_field_title', '_initfinished', '_initialize_dataset', '_initialize_instance', '_minorticks', '_plot_dict_type', '_plot_text', '_plot_type', '_plot_valid', '_profile', '_profile_valid', '_recreate_profile', '_repr_html_', '_set_figure_size', '_set_font_properties', '_setup_plots', '_shading', '_switch_ds', '_text_kwargs', '_text_xpos', '_text_ypos', '_xlabel', '_xlim', '_ylabel', '_ylim', 'annotate_text', 'annotate_title', 'data_source', 'display', 'ds', 'fields', 'figure_size', 'from_profile', 'get_log', 'hide_axes', 'hide_colorbar', 'plot_title', 'plots', 'profile', 'refresh', 'render', 'reset_plot', 'save', 'set_background_color', 'set_cmap', 'set_colorbar_label', 'set_colorbar_minorticks', 'set_figure_size', 'set_font', 'set_font_size', 'set_log', 'set_minorticks', 'set_norm', 'set_title', 'set_transform', 'set_unit', 'set_xlabel', 'set_xlim', 'set_ylabel', 'set_ylim', 'set_zlim', 'show', 'show_axes', 'show_colorbar', 'ts', 'x_log', 'y_log', 'z_log', 'z_title'] or if it is because I am missing something here is the codes to generate a ParticlePhasePlot: ptcslc = yt.ParticlePhasePlot( ds, ptc_xname, ptc_yname, [ptc_zname], color=ptc_colorname, weight_field=('particles', 'Ones'), x_bins=400, y_bins=400 ) print(dir(ptcslc)) best wishes, Yifeng He