def_physical_type#
- astropy.units.physical.def_physical_type(unit, name)[source]#
 Add a mapping between a unit and the corresponding physical type(s).
If a physical type already exists for a unit, add new physical type names so long as those names are not already in use for other physical types.
- Parameters:
 - unit
Unit The unit to be represented by the physical type.
- name
strorsetofstr A
strrepresenting the name of the physical type of the unit, or asetcontaining strings that represent one or more names of physical types.
- unit
 - Raises:
 ValueErrorIf a physical type name is already in use for another unit, or if attempting to name a unit as
"unknown".
Notes
For a list of physical types, see
astropy.units.physical.