casfiltr.m

Digital signal processing using Matlab一書之範例程式

function y = casfiltr(b0,B,A,x);
% CASCADE form realization of IIR and FIR filters
% -----------------------------------------------
% y = casfiltr(b0,B,A,x);
%  y = output sequence
% b0 = gain coefficient of CASCADE form
%  B = K by 3 matrix of real coefficients containing bk's
%  A = K by 3 matrix of real coefficients containing ak's
%  x = input sequence
%
[K,L] = size(B);
N = length(x);
w = zeros(K+1,N);
w(1,:) = x;
for i = 1:1:K
        w(i+1,:) = filter(B(i,:),A(i,:),w(i,:));
end
y = b0*w(K+1,:);