frm_trk2.m

这是一个用于语音信号处理的工具箱

%
% To find out the first four formant frequencies 
% and their bandwidths from the transfer function
% Author : Minkyu Lee
% Date : 26-Oct-1994
%

function [ff, fb] = form_trk2(A, Ts)

x=cplxpair(roots(A));
for ii=floor(length(x)/2):-1:1
	ff(ii)=angle(x(ii*2))*1/(2*pi*Ts);
	fb(ii)=-2*log(abs(x(ii*2)))/Ts;
end
[Y I]=sort(fb);
fb=[fb(I(1)) fb(I(2)) fb(I(3)) fb(I(4)) fb(I(5))];
ff=[ff(I(1)) ff(I(2)) ff(I(3)) ff(I(4)) ff(I(5))];
%FB=[];
%for ii=1:length(I)
	%FB=[FB fb(I(ii))];
%end
%FF=[];
%for ii=1:length(I)
	%FF=[FF ff(I(ii))];
%end
[Y I]=sort(ff);
fb=[fb(I(1)) fb(I(2)) fb(I(3)) fb(I(4)) fb(I(5))];
ff=[ff(I(1)) ff(I(2)) ff(I(3)) ff(I(4)) ff(I(5))];
%FB=[];
%for ii=1:length(I)
	%FB=[FB fb(I(ii))];
%end
%FF=[];
%for ii=1:length(I)
	%FF=[FF ff(I(ii))];
%end