zmapping.m

MATLAB信号处理扩展函数,用于信号处理的扩展函数

function [bz,az]=zmapping(bZ,aZ,Nz,Dz);%数字滤波器频率变换
         bzord=(length(bZ)-1)*(length(Nz)-1);
         azord=(length(aZ)-1)*(length(Dz)-1);
         bz=zeros(1,bzord+1);
         for k=0:bzord
             pln=[1];
             for l=0:k-1;
                 pln=conv(pln,Nz);
             end
             pld=[1];
             for l=0:bzord-k-1
                 pld=conv(pld,Dz);
             end
             bz=bz+bZ(k+1)*conv(pln,pld);
         end
         az=zeros(1,azord+1);
         for k=0:azord
             pln=[1];
             for l=0:k-1
                 pln=conv(pln,Nz);
             end
             pld=[1];
             for l=0:azord-k-1
                 pld=conv(pld,Dz);
             end
             az=az+aZ(k+1)*conv(pln,pld);
         end 
         az1=az(1);
         az=az/az1;bz=bz/az1;