pfe2rfz.m

Digital signal processing using Matlab一書之範例程式

function [b,a] = pfe2rfz(R,P,C)
% Rational function from Partial Fraction Expansions in z-Domain
% --------------------------------------------------------------
% [b,a] = pfe2rfz(R,P,C)
%  b = numerator polynomial coefficients [b0,b1,...,bM] of rational function,
%  a = denominator polynomial coefficients [a0,a1,...,aN] of rational function,
%  R = row vector containing residues evaluated at poles in p vector,
%  p = row vector containing poles of the rational (roots of a),
%  C = (M-N) length (or null) vector containing poly coeffcients.
%
R = R'; p = p';
[b1,a1]=residue(R,P,[]);
b1=fliplr(b1); a1=fliplr(a1);
[r,p,k]=residue(b1,a1);
[b,a]=residue(r,p,fliplr(C));
b=fliplr(b); a=fliplr(a);
b=real(b); a=real(a);
b=b/a(1); a=a/a(1);