par2dir.m

Digital Signal Processing with MATLAB是Proakis於DSP的經點著作 內涵此書的source code

function [b,a] = par2dir(C,B,A);
% PARALLEL-to-DIRECT form conversion
% ----------------------------------
% [b,a] = par2dir(C,B,A)
%  b = numerator polynomial coefficients of DIRECT form
%  a = denominator polynomial coefficients of DIRECT form
%  C = Polynomial part of PARALLEL form
%  B = K by 2 matrix of real coefficients containing bk's
%  A = K by 3 matrix of real coefficients containing ak's
%
[K,L] = size(A); R = []; P = [];

for i=1:1:K
	[r,p,k]=residuez(B(i,:),A(i,:));
	R = [R;r]; P = [P;p];
end
[b,a] = residuez(R,P,C);
b = b(:)'; a = a(:)';