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,:));endy = b0*w(K+1,:);