def magnitude(scalar = scalar())
      if special?
        unit.magnitude(scalar)
      else
        value * unit.magnitude
      end
    end
def magnitude(scalar = scalar())
      if special?
        unit.magnitude(scalar)
      else
        value * unit.magnitude
      end
    end
Get a magnitude based on a linear scale value. Only used by scales with
 special atoms in it's hierarchy.
 @param scalar [Numeric] A linear scalar value
 @return [Numeric] The equivalent magnitude on this scale
 @api public