    # File lib/facets/more/quaternion.rb, line 250
      def initialize(a=0,b=0,c=0,d=0)
        raise "non numeric 1st arg `#{a.inspect}'" if !a.kind_of? Numeric;
        raise "non numeric 2nd arg `#{b.inspect}'" if !b.kind_of? Numeric;
        raise "non numeric 3rd arg `#{c.inspect}'" if !c.kind_of? Numeric;
        raise "non numeric 4th arg `#{d.inspect}'" if !d.kind_of? Numeric;
        @re=a; @im=b; @jm=c; @km=d
      end