W = makeweight(dcgain,[freq,mag],hfgain)
W = makeweight(dcgain,[freq,mag],hfgain,Ts)
W = makeweight(dcgain,[freq,mag],hfgain,Ts,N)
W = makeweight(dcgain,wc,hfgain,___)
W = makeweight(dcgain,wc,hfgain，___)表示增益交叉频率wc。该语法相当于将[freq,mag]设置为[wc,1]。可以将此语法与前面的任何输入-参数组合一起使用，以创建连续时间、离散时间或Butterworth加权函数。
例如：
makeweight(1e5,5,1e-5)
1e-05 s + 5
-----------
s + 5e-05
