New issue 751: PhasePlot is broken in 3.0 https://bitbucket.org/yt_analysis/yt/issue/751/phaseplot-is-broken-in-30 Nathan Goldbaum: I cannot create PhasePlots in 3.0. The same command works fine in the current stable release. Here is the traceback I'm seeing: ``` #!python traceback TypeError Traceback (most recent call last) <ipython-input-7-db8ac28b5d75> in <module>() ----> 1 plot = PhasePlot(dd, "CellMassMsun", "Radius", "Height") /home/goldbaum/yt-hg/yt/visualization/profile_plotter.pyc in __init__(self, data_source, x_field, y_field, z_fields, weight_field, x_bins, y_bins, accumulation, fractional, profile, fontsize, font_color, figure_size) 543 weight_field = weight_field, 544 accumulation=accumulation, --> 545 fractional=fractional) 546 self.profile = profile 547 ImagePlotContainer.__init__(self, data_source, profile.field_data.keys(), /home/goldbaum/yt-hg/yt/data_objects/profiles.pyc in create_profile(data_source, bin_fields, n, weight_field, fields, accumulation, fractional) 998 setattr(obj, "fractional", fractional) 999 if fields is not None: -> 1000 obj.add_fields(fields) 1001 for field in fields: 1002 if fractional: /home/goldbaum/yt-hg/yt/data_objects/profiles.pyc in add_fields(self, fields) 758 fields = ensure_list(fields) 759 temp_storage = ProfileFieldAccumulator(len(fields), self.size) --> 760 for g in parallel_objects(self.data_source._grids): 761 self._bin_grid(g, fields, temp_storage) 762 self._finalize_storage(fields, temp_storage) /home/goldbaum/yt-hg/yt/utilities/parallel_tools/parallel_analysis_interface.pyc in parallel_objects(objects, njobs, storage, barrier, dynamic) 431 # If our objects object is slice-aware, like time series data objects are, 432 # this will prevent intermediate objects from being created. --> 433 oiter = itertools.islice(enumerate(objects), my_new_id, None, njobs) 434 for obj_id, obj in oiter: 435 result_id = obj_id * njobs + my_new_id TypeError: 'NoneType' object is not iterable ``` Looking at the traceback, the issue seems to be that the profile code expects there to be a `_grids` attribute attached to data sources.