说明：  用c++编的巴特沃斯带阻滤波器原程序，可得带阻滤波器数字系统函数的各阶系数．可在ＭＡＴＬＡＢ中用ＦＩＬＴＥＲ函数进行测试，好象还没有带阻的
(With c++ Series Butterworth band stop filter the original procedure, available band-stop filter digital system function coefficient of each order. FILTER can be used in the MATLAB function testing, as if not yet the band-stop)