New issue 557: Hardcoded values are used in several places in the code https://bitbucket.org/yt_analysis/yt/issue/557/hardcoded-values-are-used-in-... Kacper Kowalik: Several physical constants are defined across multiple places in the code. As an example: ``` #!bash $ grep '1\.98' -r analysis_modules/halo_finding/halo_objects.py: #Jc = 1.98892e33/pf['mpchcm']*1e5 analysis_modules/halo_profiler/multi_halo_profiler.py: Msun2g = 1.989e33 utilities/units.py: "Msun": (1.98892e33, mass), utilities/tests/test_units.py: msun_cgs = 1.98892e33 utilities/tests/test_units.py: Msun_cgs = 1.98892e33 utilities/physical_constants.py:mass_sun_cgs = 1.98841586e33 # g frontends/nyx/fields.py: return (1/1.989e33) frontends/nyx/data_structures.py: self.units["particle_mass"] = 1.989e33 frontends/flash/fields.py: return 1.0/1.989e33 frontends/art/data_structures.py: cf["Mass"] = aM0 * 1.98892e33 frontends/castro/fields.py: return 1.0 / 1.989e33 frontends/castro/data_structures.py: self.units['particle_mass'] = 1.989e33 ### TODO: Make a global solar mass def frontends/enzo/fields.py: return data.convert("Density")*((data.convert("cm")**3.0)/1.989e33) frontends/ramses/fields.py: return data.convert("Density")*((data.convert("cm")**3.0)/1.989e33) data_objects/universal_fields.py: (3/(4*3.1415926535897931))**(0.5) / 1.989e33 data_objects/derived_quantities.py: spin = J * E / (M*1.989e33*G) ``` Instead constants should be imported from `yt.physical_constants` everywhere for the sake of consistency. Responsible: xarthisius