音频处理Matlab程序

				function [b,a] = un_buttap(N,Omegac);
				%   b=Ha(s)分子多项式系数
				%   a=Ha(s)分母多项式系数
				%   N=巴特沃兹模拟原型滤波器的阶次
				%   OmegaC=截止频率弧度/秒
				[z0,p0,k0] =buttap(N);
				    p=p0*Omegac;
				    k=k0*Omegac^N;
				    B=real(poly(z0));
				    b=k*B;
				    a=real(poly(p));