clc;
close all;
clear all;

% semestralka
rawText = fileread('data6.dat');
nums = regexp(rawText, '[-+]?\d+', 'match');
data = int16(str2double(nums));

X = DFT_priama(double(data));
n = length(X);
Fs = 200;
freq = (0:n-1)*Fs/n;

figure;
plot(double(data));
figure;
plot(freq, X)
%3
figure;
magX = abs(X);
plot(freq, magX)
%4
% freq shift pre -Fs/2 po Fs/2
freq_shift = (-n/2:n/2-1)*(Fs/n);
figure;
subplot(2,1,1);
plot(freq_shift, real(fftshift(X)));
title('Reálna časť posunutého spektra');
xlabel('Frekvencia [Hz]');
ylabel('Reálna hodnota');
subplot(2,1,2);
plot(freq_shift, imag(fftshift(X)), 'r');
title('Imaginárna časť posunutého spektra');
xlabel('Frekvencia [Hz]');
ylabel('Imaginárna hodnota');
set(gcf, 'PaperPosition', [0 0 1.7*6 0.75*4.2]);
set(gcf, 'PaperSize', [1.7*6 0.75*4.2]);
set(gcf, 'Color', 'none'); set(gca, 'Color', 'none');
print('-depsc', 'fig_im_real_semC.eps');
%5
figure;
plot(freq, imag(X), 'r');
%6
figure;
plot(freq, real(X));
%7
figure;
% fazove spektrum
plot(freq, angle(X))

[pks, locs] = findpeaks(magX, 'NPeaks', 10, 'SortStr', 'descend');
f0 = freq(locs)
f0b = f0(f0 < 100); % nyquistov teorem
f0_ohranicene = f0b

f0_ohranicene(f0_ohranicene < 2) = [];
r = 0.975;
b = 1;
a = 1;

for k = 1:length(f0_ohranicene)
    theta = 2*pi*(f0_ohranicene(k)/Fs);
    b = conv(b, [1, -2*cos(theta), 1]);
    a = conv(a, [1, -2*r*cos(theta), r^2]);
end

figure;
zplane(b, a);
title('Nuly a póly filtra');
xlabel('Reálna časť');
ylabel('Imaginárna časť');
set(gcf, 'Color', 'none'); set(gca, 'Color', 'none');
print('-depsc', 'fig1_semC.eps');

figure;
freqz(b, a);
title('Frekvenčná charakteristika (1)');
xlabel('Frekvencia [Hz]');
ylabel('Zosilnenie [dB]');
set(gcf, 'Color', 'none'); set(gca, 'Color', 'none');
print('-depsc', 'fig2_semC.eps');

figure;
freqz(b, a);
title('Frekvenčná charakteristika (2)');
xlabel('Frekvencia [Hz]');
ylabel('Zosilnenie [dB]');
set(gcf, 'Color', 'none'); set(gca, 'Color', 'none');
print('-depsc', 'fig3_semC.eps');

filtered_data = filter(b, a, double(data));
figure;
plot(filtered_data);
title('Filtrovaný signál');
xlabel('Vzorky');
ylabel('Amplitúda');
grid on;
set(gcf, 'Color', 'none'); set(gca, 'Color', 'none');
set(gcf, 'PaperPosition', [0 0 1.7*6 0.75*4.2]);
set(gcf, 'PaperSize', [1.7*6 0.75*4.2]);
print('-depsc', 'fig4_semC.eps');