Hey All, I am having a problem running rockstar with yt. I am updating a python 2 code that was used to run the same simulations I am running, but am getting 2 errors when running it. The first error occurs in this section of code: if MPI.COMM_WORLD.Get_rank()==0: print() print('Beginning Rockstar analysis in ', sim_dir) print('Placing output in ', out_dir) # Generate data series snap_base = sim_dir+ '/' + snap_base + '*' ts = yt.DatasetSeries(snap_base) if len(ts) > 1: first_snap = ts[0] last_snap = ts[-1] if MPI.COMM_WORLD.Get_rank()==0: print('first snapshot: ', first_snap.basename) print('last snapshot: ', last_snap.basename) else: last_snap = ts[0] if MPI.COMM_WORLD.Get_rank()==0: print('snapshot: ', last_snap.basename) # Create particle union if needed particle_type = particle_types[0] ad = last_snap.all_data() particle_masses = yt.np.unique(ad[(particle_type, 'particle_mass')].in_units('Msun/h')) total_particles = ad.quantities.total_quantity((particle_type, "particle_ones")) if MPI.COMM_WORLD.Get_rank()==0: print('Using particle(s) ', particle_types, ' with mass(es) ', particle_masses) print() When the script gets to the total_particles = ad.quantities...., I get this error: File "./runrockstar.py", line 269, in <module> num_readers=args['num_readers']) File "./runrockstar.py", line 149, in run_rockstar particle_masses = yt.np.unique(ad[(particle_type, 'particle_mass')].in_units('Msun/h')) File "/home1/sflarkin/build/yt-conda/src/yt-git/yt/data_objects/data_containers.py", line 282, in __getitem__ self.get_data(f) File "/home1/sflarkin/build/yt-conda/src/yt-git/yt/data_objects/data_containers.py", line 1334, in get_data particles, self, self._current_chunk) File "/home1/sflarkin/build/yt-conda/src/yt-git/yt/geometry/geometry_handler.py", line 227, in _read_particle_fields fields_to_read) File "/home1/sflarkin/build/yt-conda/src/yt-git/yt/utilities/io_handler.py", line 199, in _read_particle_selection psize = self._count_particles_chunks(chunks, ptf, selector) File "/home1/sflarkin/build/yt-conda/src/yt-git/yt/utilities/io_handler.py", line 170, in _count_particles_chunks for ptype, (x, y, z) in self._read_particle_coords(chunks, ptf): File "/home1/sflarkin/build/yt-conda/src/yt-git/yt/frontends/art/io.py", line 102, in _read_particle_coords x = self._get_field((ptype, "particle_position_x")) File "/home1/sflarkin/build/yt-conda/src/yt-git/yt/frontends/art/io.py", line 139, in _get_field tr[field] = rp([ax])[0]/dd - off File "/home1/sflarkin/build/yt-conda/src/yt-git/yt/frontends/art/io.py", line 134, in <lambda> idxb=idxb, fields=ax) File "/home1/sflarkin/build/yt-conda/src/yt-git/yt/frontends/art/io.py", line 458, in read_particles ranges = get_ranges(skip, count, field, **kwargs) File "/home1/sflarkin/build/yt-conda/src/yt-git/yt/frontends/art/io.py", line 425, in get_ranges for page in range(num_pages): P001 yt : [ERROR ] 2018-07-17 15:24:08,955 TypeError: 'float' object cannot be interpreted as an integer P001 yt : [ERROR ] 2018-07-17 15:24:08,955 Error occured on rank 1. I am not sure why this is occuring, and if I am missing something obvious. The other error occurs when attempting to clear the cache, done as follows: if len(ts) > 1 : del first_snap del last_snap _cached_datasets.clear() but _cached_datasets is said as not defined, despite being called by an earlier call of: from yt.data_objects.static_output import _cached_datasets I am wondering if this is the correct way to go about that? Thanks