Hi again Nathan,
I have modified my script to run on the output_00080 cosmological RAMSES run from http://yt-project.org/data/.
The script is uploaded with link: http://use.yt/upload/9d91ea29.
When I run this example I get a similar traceback:
Traceback (most recent call last):
File "/home/lhw28/.local/lib/python3.6/site-packages/yt/data_objects/data_containers.py", line 308, in _generate_fluid_field
finfo.check_available(gen_obj)
File "/home/lhw28/.local/lib/python3.6/site-packages/yt/fields/derived_field.py", line 204, in check_available
validator(data)
File "/home/lhw28/.local/lib/python3.6/site-packages/yt/fields/derived_field.py", line 470, in __call__
raise NeedsGridType(self.ghost_zones,self.fields)
yt.fields.field_exceptions.NeedsGridType: (0, None)
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "yt_issue.py", line 58, in <module>
center=centre, data_source=box)
File "/home/lhw28/.local/lib/python3.6/site-packages/yt/data_objects/construction_data_containers.py", line 270, in __init__
self.get_data(field)
File "/home/lhw28/.local/lib/python3.6/site-packages/yt/data_objects/construction_data_containers.py", line 344, in get_data
self._handle_chunk(chunk, fields, tree)
File "/home/lhw28/.local/lib/python3.6/site-packages/yt/data_objects/construction_data_containers.py", line 450, in _handle_chunk
d = chunk[field] * dl
File "/home/lhw28/.local/lib/python3.6/site-packages/yt/data_objects/data_containers.py", line 255, in __getitem__
self.get_data(f)
File "/home/lhw28/.local/lib/python3.6/site-packages/yt/data_objects/data_containers.py", line 1382, in get_data
self._generate_fields(fields_to_generate)
File "/home/lhw28/.local/lib/python3.6/site-packages/yt/data_objects/data_containers.py", line 1402, in _generate_fields
fd = self._generate_field(field)
File "/home/lhw28/.local/lib/python3.6/site-packages/yt/data_objects/data_containers.py", line 292, in _generate_field
tr = self._generate_fluid_field(field)
File "/home/lhw28/.local/lib/python3.6/site-packages/yt/data_objects/data_containers.py", line 310, in _generate_fluid_field
rv = self._generate_spatial_fluid(field, ngt_exception.ghost_zones)
File "/home/lhw28/.local/lib/python3.6/site-packages/yt/data_objects/data_containers.py", line 330, in _generate_spatial_fluid
ind += o.select(self.selector, self[field], rv, ind)
File "/home/lhw28/.local/lib/python3.6/site-packages/yt/data_objects/data_containers.py", line 255, in __getitem__
self.get_data(f)
File "/home/lhw28/.local/lib/python3.6/site-packages/yt/data_objects/data_containers.py", line 1382, in get_data
self._generate_fields(fields_to_generate)
File "/home/lhw28/.local/lib/python3.6/site-packages/yt/data_objects/data_containers.py", line 1402, in _generate_fields
fd = self._generate_field(field)
File "/home/lhw28/.local/lib/python3.6/site-packages/yt/data_objects/data_containers.py", line 292, in _generate_field
tr = self._generate_fluid_field(field)
File "/home/lhw28/.local/lib/python3.6/site-packages/yt/data_objects/data_containers.py", line 312, in _generate_fluid_field
rv = finfo(gen_obj)
File "/home/lhw28/.local/lib/python3.6/site-packages/yt/fields/derived_field.py", line 256, in __call__
dd = self._function(self, data)
File "/home/lhw28/.local/lib/python3.6/site-packages/yt/fields/particle_fields.py", line 133, in particle_density
pos = data[ptype, coord_name].convert_to_units("code_length")
File "/home/lhw28/.local/lib/python3.6/site-packages/yt/data_objects/octree_subset.py", line 73, in __getitem__
tr = super(OctreeSubset, self).__getitem__(key)
File "/home/lhw28/.local/lib/python3.6/site-packages/yt/data_objects/data_containers.py", line 255, in __getitem__
self.get_data(f)
File "/home/lhw28/.local/lib/python3.6/site-packages/yt/data_objects/data_containers.py", line 1325, in get_data
self.get_data(apply_fields[filter_type])
File "/opt/ioa/software/anaconda/anaconda36/envs/20181213_2_py36/lib/python3.6/contextlib.py", line 88, in __exit__
next(self.gen)
File "/home/lhw28/.local/lib/python3.6/site-packages/yt/data_objects/particle_filters.py", line 53, in apply
raise YTIllDefinedFilter(self, tr.shape, filter.shape)
yt.utilities.exceptions.YTIllDefinedFilter: Filter '