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function [F]=frmnts1(a,fs) 
% FRMNTS1   Determine the formants given the LPC coefficients 
%   The function determines the formans by taking the roots of the 
%   LPC polynomial. For further details, see digital speech processing 
%   by Rabiner and Shafer 
%   Input: a    : LPC coefficients 
%          fs   : Sampling frequency 
 
% Satrajit Ghosh, SpeechLab, Boston University. (c)2001 
% $Header: /DIVA.1/classes/@d_opvt/private/frmnts1.m 5     10/19/01 11:19a Satra $ 
 
% $NoKeywords: $ 
 
% Setup globals 
global RELEASE 
 
const=fs/(2*pi); 
rts=roots(a); 
k=1; 
save = []; 
 
for i=1:length(a)-1 
    re=real(rts(i));  
    im=imag(rts(i)); 
     
    formn=const*atan2(im,re);        %formant frequencies 
    bw=-2*const*log(abs(rts(i)));    %formant bandwidth 
     
    % If the bandwidths and formants are reasonable, save them    
    if formn>90 & bw <700 & formn<4000 
        save(k)=formn; 
        bandw(k)=bw; 
        k=k+1; 
    end 
     
end 
 
[y, ind]=sort(save); 
F = [NaN NaN NaN]; 
F(1:min(3,length(y))) = y(1:min(3,length(y))); 
F = F(:);