zmapping.m

来自「很多matlab的源代码」· M 代码 · 共 38 行

function [bz,az] = zmapping(bZ,aZ,Nz,Dz)
% Frequency band Transformation from Z-domain to z-domain
% ----------------------------------------------------------
% [bz,az] = zmapping(bZ,aZ,Nz,Dz)
% performs:
%              b(z)       b(Z)|
%              ----   =   ----|     N(z)
%              a(z)       a(Z)|@Z = ----
%                                   D(z)
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;