public interface Unit
Interface used to specify the physical units to be used when inputting or
outputting a quantity. All internal calculations are performed using
simulation units, which are all derived from the picosecond, Dalton, and
Angstrom. Classes implementing this interface convert the simulation units
to a more common unit for interfacing with the user.
I/O classes (normally Device and Display) have associated with them a
class that implements the Unit interface. In addition to providing
conversions, the unit class also provides textual labels that can be used by
a Device or Display to indicate the units is it using.