New issue 1027: yt.load_particles cannot find newly derived fields https://bitbucket.org/yt_analysis/yt/issue/1027/ytload_particles-cannot-find... Benjamin Thompson: This script. ``` #!python import numpy as np import yt from yt.units.yt_array import YTArray from yt.units import kiloparsec, Msun, kilometer, second, Gyr def _do_magick(field, data): rv = data[("all","particle_birth_epoch")] * 10.0 return rv n_data = 3000 sim_data_verb = {"particle_mass": YTArray(np.random.rand(n_data) * 1000,"Msun"), "particle_position_x": YTArray(np.random.rand(n_data),"kpc"), "particle_position_y": YTArray(np.random.rand(n_data),"kpc"), "particle_position_z": YTArray(np.random.rand(n_data),"kpc"), "particle_velocity_x": YTArray(np.random.rand(n_data), "kpc/s"), "particle_velocity_y": YTArray(np.random.rand(n_data), "kpc/s"), "particle_velocity_z": YTArray(np.random.rand(n_data), "kpc/s"), "particle_mass_birth_epoch": YTArray(np.random.rand(n_data), "Msun"), "particle_birth_epoch": YTArray(np.random.rand(n_data), "Gyr"), "particle_metallicity": YTArray(np.random.rand(n_data),"dimensionless") } bbox = yt.YTArray(np.array([[0,1],[0,1],[0,1]]),"kpc") ds = yt.load_particles(sim_data_verb, length_unit=kiloparsec, mass_unit=Msun, time_unit=second, bbox=bbox, n_ref=256) ds.add_field(name = ('all','particle_birth_epoch_two'),function=_do_magick, units="Gyr") ad = ds.all_data() print ds.derived_field_list print ad[('all','particle_birth_epoch_two')] ``` returns this error File "yt_example2.py", line 35, in <module> print ad[('all','particle_birth_epoch_two')] File "/home/ben/.local/lib/python2.7/site-packages/yt-3.2dev-py2.7-linux-x86_64.egg/yt/data_objects/data_containers.py", line 246, in __getitem__ f = self._determine_fields([key])[0] File "/home/ben/.local/lib/python2.7/site-packages/yt-3.2dev-py2.7-linux-x86_64.egg/yt/data_objects/data_containers.py", line 541, in _determine_fields raise YTFieldTypeNotFound(ftype) yt.utilities.exceptions.YTFieldTypeNotFound: Could not find field 'all'. It seems as though it cannot find the newly derived field _______________________________________________ yt-dev mailing list yt-dev@lists.spacepope.org http://lists.spacepope.org/listinfo.cgi/yt-dev-spacepope.org