### Side-effects of Changing the Unit attribute

If an AxisAxis has an active Unit attribute, changing its value (either by setting a new value or by clearing it so that the default value is re-instated) may cause the Label and Symbol attributes to be changed accordingly. For instance, if an Axis has Unit, Label and Symbol of “Hz”, “Frequency” and “nu”, then changing its Unit attribute to “log(Hz)” will cause AST to change its Label and Symbol to “log(Frequency)” and “Log(nu)”. These changes are only made if the Unit attribute is active, and a MappingMapping can be found from the old units to the new units. On the other hand, changing the Unit from “Hz” to “MHz” would not cause any change to the Label or Symbol attributes.