import yt

from yt.units import kpc

import numpy as np

import yt.visualization.eps_writer as eps

from yt.data_objects.particle_filters import add_particle_filter

from matplotlib import pyplot as plt

plt.switch_backend('agg')

def old(pfilter, data):
        age = data["all", "particle_age"]
        old_only = data["all", "particle_mass"]
        filter = np.logical_and(age.in_units('Myr') == 0, old_only.in_units('Msun') < 4e6)

        return filter

filename="/lunarc/nobackup/users/samvad/FINAL-50-0.5/output/output_00048/info_00048.txt"
ds=yt.load(filename)
ds.add_particle_filter('old')
ad=ds.all_data()

print(ad[('deposit', 'old_cic')]) 

Traceback (most recent call last):

  File "com.py", line 45, in <module>

    print(ad[('deposit', 'old_cic')])

  File "/home/samvad/yt-conda/lib/python3.6/site-packages/yt/data_objects/data_containers.py", line 281, in __getitem__

    self.get_data(f)

  File "/home/samvad/yt-conda/lib/python3.6/site-packages/yt/data_objects/data_containers.py", line 1336, in get_data

    self._generate_fields(fields_to_generate)

  File "/home/samvad/yt-conda/lib/python3.6/site-packages/yt/data_objects/data_containers.py", line 1356, in _generate_fields

    fd = self._generate_field(field)

  File "/home/samvad/yt-conda/lib/python3.6/site-packages/yt/data_objects/data_containers.py", line 318, in _generate_field

    tr = self._generate_fluid_field(field)

  File "/home/samvad/yt-conda/lib/python3.6/site-packages/yt/data_objects/data_containers.py", line 336, in _generate_fluid_field

    rv = self._generate_spatial_fluid(field, ngt_exception.ghost_zones)

  File "/home/samvad/yt-conda/lib/python3.6/site-packages/yt/data_objects/data_containers.py", line 356, in _generate_spatial_fluid

    ind += o.select(self.selector, self[field], rv, ind)

  File "/home/samvad/yt-conda/lib/python3.6/site-packages/yt/data_objects/data_containers.py", line 281, in __getitem__

    self.get_data(f)

  File "/home/samvad/yt-conda/lib/python3.6/site-packages/yt/data_objects/data_containers.py", line 1336, in get_data

    self._generate_fields(fields_to_generate)

  File "/home/samvad/yt-conda/lib/python3.6/site-packages/yt/data_objects/data_containers.py", line 1356, in _generate_fields

    fd = self._generate_field(field)

  File "/home/samvad/yt-conda/lib/python3.6/site-packages/yt/data_objects/data_containers.py", line 318, in _generate_field

    tr = self._generate_fluid_field(field)

  File "/home/samvad/yt-conda/lib/python3.6/site-packages/yt/data_objects/data_containers.py", line 338, in _generate_fluid_field

    rv = finfo(gen_obj)

  File "/home/samvad/yt-conda/lib/python3.6/site-packages/yt/fields/derived_field.py", line 237, in __call__

    dd = self._function(self, data)

  File "/home/samvad/yt-conda/lib/python3.6/site-packages/yt/fields/particle_fields.py", line 143, in particle_cic

    d = data.deposit(pos, [data[ptype, mass_name]], method = "cic")

  File "/home/samvad/yt-conda/lib/python3.6/site-packages/yt/data_objects/octree_subset.py", line 186, in deposit

    op.initialize()

  File "yt/geometry/particle_deposit.pyx", line 345, in yt.geometry.particle_deposit.CICDeposit.initialize

yt.utilities.exceptions.YTBoundsDefinitionError: <exception str() failed>