def __create_navigator(self, main_root):
		navigator_dir = os.path.join(main_root, 'navigator')
		safe_mkdir(navigator_dir)

		navigators = self.__config_mgr.navigator()
		self.__navigator_mgr.create_navigators(navigators, navigator_dir)
def getAp3(self):
        ret = math.acos(((self.getLenp1() * self.getLenp1() + self.getLenp2() * self.getLenp2()) - self.getLenp3() * self.getLenp3()) / (2* self.getLenp1() * self.getLenp2()))
        return ret