function fta(fileuse);
%FTA(fileuse)  Frequency Transform Analysis
%
%  fileuse ('choosenew'): whether to choose a new file set or use an old one
%
%Examples:
%  fta
%  fta('useold');

% PRODUCE PLOTS FROM RR DATA (script emailed from Thanos to Bob 8/1/00;
% modified a fair bit; later modified by Brandon Beck 5/11/02):
% ---------------------------------------------------------------------------
% RR intervals and instantaneous heart rate graphs

% Tests on the input arguments

if (nargin==0)
  fileuse = 'choosenew';
end %if

[ecgfilename, cdfilename, rrfilename, hrfilename, ecgfilenameonly] = chooser(fileuse);

fs = textread(cdfilename, '%f', 1);
[rt rr] = textread(rrfilename, '%f %f', -1, 'headerlines', 1);
[hrt hr] = textread(hrfilename, '%f %f', -1, 'headerlines', 1);
rrsize = size(rr,1);

figure(1);
subplot(2,1,1);
plot(1:rrsize,rr,'k','linewidth',1); axis tight;
xlabel('RR interval number');
ylabel('RR interval (ms)');
title('Sample DataSet', 'fontsize', 16, 'fontweight', 'b')
subplot(2,1,2);
plot(hrt, hr,'k','linewidth',1); axis tight;
xlabel('Time (ms)');
ylabel('Heart Rate (Hz)');

% ---------------------------------------------------------------------------
% WELCH'S PSD

figure(2); 
clf; 
nfft = 4*1024;
lwdth=1;
fsize=12;
fweight='b';
[p,f] = psd(hr, nfft, fs, kaiser(nfft/4,5), 0 , 0.99,'mean');
[p2,f2] = psd(hr, nfft, fs, hanning(nfft/4), 0 , 0.99,'mean');
plot(f, sqrt(p),'k', 'linewidth', lwdth);set(gca, 'xlim', [0 10]);% z;
hold on
plot(f2, sqrt(p2), 'r', 'linewidth', lwdth); set(gca, 'xlim', [0 10]);% z;
hold off
xlabel('Frequency (Hz)', 'fontsize', fsize, 'fontweight', fweight );
ylabel('Sqrt(Power)', 'fontsize', fsize, 'fontweight', fweight );
title('Welch modified periodogram', 'fontsize', 16, 'fontweight', 'b')
legend('Kaiser \beta = 4', 'Hanning' );

% ---------------------------------------------------------------------------
% Yule-Walker AR method
figure(3);
clf; 
nfft = 1024;  
np = 15; [p,f] = pyulear( hr-median(hr), np, nfft, fs);
np = 15; [p2,f2] = pburg( hr-median(hr), np, nfft, fs);
plot(f, sqrt(p),'k', 'linewidth', lwdth); set(gca, 'xlim', [0 10]); %z;
hold on
plot(f2, sqrt(p2), 'r', 'linewidth', lwdth); set(gca, 'xlim', [0 10]); %z;
hold off
xlabel('Frequency (Hz)', 'fontsize', fsize, 'fontweight', fweight );
ylabel('Sqrt(Power)', 'fontsize', fsize, 'fontweight', fweight );
title('Autoregressive Methods', 'fontsize', 16, 'fontweight', 'b')
legend('Yule-Walker', 'Burg');

% ---------------------------------------------------------------------------
% MUSIC

figure(4);
clf; 
nfft = 2*1024; [p,f] = pmusic( hr-median(hr), 20, nfft, fs ); 
plot(f, sqrt(p),'k', 'linewidth', lwdth); set(gca, 'xlim', [0 10]); %z;
xlabel('Frequency (Hz)', 'fontsize', fsize, 'fontweight', fweight );
ylabel('Sqrt(Power)', 'fontsize', fsize, 'fontweight', fweight );
title('Multiple Signal Classification Method (MUSIC)', 'fontsize', 16, 'fontweight', 'b')