New issue 592: Fields that combine deposited particle quantities with gas do not work https://bitbucket.org/yt_analysis/yt/issue/592/fields-that-combine-deposited... Nathan Goldbaum: This was exposed on an enzo-3.0 dataset, but I've reproduced it using IsolatedGalaxy. One minor note: the yt-3.0 `TotalMass` field still depends on `Dark_Matter_Density`. I can't remember if we merged from yt-2.6dev before that was patched so this might not be a merge error, but I suspect it is. In any case, the `Matter_Density` correctly uses `particle_density`, so I've used it below: ``` #!python $ yt plot -a 2 -w 25 -u kpc -f Matter_Density IsolatedGalaxy/galaxy0030/galaxy0030 yt : [INFO ] 2013-06-12 18:42:33,994 Parameters: current_time = 0.00600002000283 yt : [INFO ] 2013-06-12 18:42:33,994 Parameters: domain_dimensions = [32 32 32] yt : [INFO ] 2013-06-12 18:42:33,995 Parameters: domain_left_edge = [ 0. 0. 0.] yt : [INFO ] 2013-06-12 18:42:33,995 Parameters: domain_right_edge = [ 1. 1. 1.] yt : [INFO ] 2013-06-12 18:42:33,996 Parameters: cosmological_simulation = 0.0 yt : [INFO ] 2013-06-12 18:42:33,996 Adding plot for axis 2 Parsing Hierarchy100% |||||||||||||||||||||||||||||||||||||||||| Time: 00:00:00 yt : [INFO ] 2013-06-12 18:42:34,018 Gathering a field list (this may take a moment.) yt : [INFO ] 2013-06-12 18:42:34,031 Adding unknown field SFR_Density to list of fields yt : [INFO ] 2013-06-12 18:42:34,031 Adding unknown field Forming_Stellar_Mass_Density to list of fields yt : [INFO ] 2013-06-12 18:42:34,031 Adding unknown field Galaxy1Colour to list of fields yt : [INFO ] 2013-06-12 18:42:34,031 Adding unknown field kphHeI to list of fields yt : [INFO ] 2013-06-12 18:42:34,031 Adding unknown field MBHColour to list of fields yt : [INFO ] 2013-06-12 18:42:34,032 Adding unknown field Phi_pField to list of fields yt : [INFO ] 2013-06-12 18:42:34,032 Adding unknown field Galaxy2Colour to list of fields yt : [INFO ] 2013-06-12 18:42:34,032 Adding unknown field Average_creation_time to list of fields yt : [INFO ] 2013-06-12 18:42:34,032 Adding unknown field gammaHI to list of fields yt : [INFO ] 2013-06-12 18:42:34,032 Adding unknown field kphHI to list of fields yt : [INFO ] 2013-06-12 18:42:34,032 Adding unknown field kphHeII to list of fields yt : [INFO ] 2013-06-12 18:42:34,032 Adding unknown field Star_Particle_Density to list of fields yt : [INFO ] 2013-06-12 18:42:34,036 Adding unknown field PhiField to list of fields Traceback (most recent call last): File "/usr/local/share/python/yt", line 9, in <module> load_entry_point('yt==3.0dev', 'console_scripts', 'yt')() File "/Users/goldbaum/Documents/yt-3.0/yt/utilities/command_line.py", line 1691, in run_main args.func(args) File "/Users/goldbaum/Documents/yt-3.0/yt/utilities/command_line.py", line 97, in run self(args) File "/Users/goldbaum/Documents/yt-3.0/yt/utilities/command_line.py", line 1319, in __call__ width=width) File "/Users/goldbaum/Documents/yt-3.0/yt/visualization/plot_window.py", line 1246, in __init__ slc.get_data(fields) File "/Users/goldbaum/Documents/yt-3.0/yt/data_objects/data_containers.py", line 521, in get_data self._generate_fields(fields_to_generate) File "/Users/goldbaum/Documents/yt-3.0/yt/data_objects/data_containers.py", line 537, in _generate_fields self.field_data[field] = self._generate_field(field) File "/Users/goldbaum/Documents/yt-3.0/yt/data_objects/data_containers.py", line 226, in _generate_field return self._generate_fluid_field(field) File "/Users/goldbaum/Documents/yt-3.0/yt/data_objects/data_containers.py", line 242, in _generate_fluid_field rv = finfo(gen_obj) File "/Users/goldbaum/Documents/yt-3.0/yt/data_objects/field_info_container.py", line 482, in __call__ dd = self._function(self, data) File "/Users/goldbaum/Documents/yt-3.0/yt/data_objects/universal_fields.py", line 411, in _Matter_Density return (data['Density'] + data['particle_density']) TypeError: unsupported operand type(s) for +: 'NoneType' and 'float' ``` I put a breakpoint inside `_Matter_Density` and It looks like an exception is raised when yt attempts to retrieve `particle_density` during field detection. This exception is never raised to the user level (see #589) so execution proceeds normally. When the field is finally called by the script, 'Density' is returned as `None`, I guess since the field detection didn't finish properly. Responsible: MatthewTurk