def normalize()
      mag = Math.sqrt(self.x*self.x + self.y*self.y + self.z*self.z)
      return Quat.new(self.x/mag, self.y/mag, self.z/mag, self.w/mag)
    end
def normalize()
      mag = Math.sqrt(self.x*self.x + self.y*self.y + self.z*self.z)
      return Quat.new(self.x/mag, self.y/mag, self.z/mag, self.w/mag)
    end
[Output]
  return normalized result as Quat.