103 lines
2.3 KiB
Matlab
103 lines
2.3 KiB
Matlab
clc;
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close all;
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clear all;
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% semestralka
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rawText = fileread('data6.dat');
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nums = regexp(rawText, '[-+]?\d+', 'match');
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data = int16(str2double(nums));
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X = DFT_priama(double(data));
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n = length(X);
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Fs = 200;
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freq = (0:n-1)*Fs/n;
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figure;
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plot(double(data));
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figure;
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plot(freq, X)
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%3
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figure;
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magX = abs(X);
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plot(freq, magX)
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%4
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% freq shift pre -Fs/2 po Fs/2
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freq_shift = (-n/2:n/2-1)*(Fs/n);
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figure;
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subplot(2,1,1);
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plot(freq_shift, real(fftshift(X)));
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title('Reálna časť posunutého spektra');
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xlabel('Frekvencia [Hz]');
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ylabel('Reálna hodnota');
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subplot(2,1,2);
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plot(freq_shift, imag(fftshift(X)), 'r');
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title('Imaginárna časť posunutého spektra');
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xlabel('Frekvencia [Hz]');
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ylabel('Imaginárna hodnota');
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set(gcf, 'PaperPosition', [0 0 1.7*6 0.75*4.2]);
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set(gcf, 'PaperSize', [1.7*6 0.75*4.2]);
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set(gcf, 'Color', 'none'); set(gca, 'Color', 'none');
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print('-depsc', 'fig_im_real_semC.eps');
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%5
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figure;
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plot(freq, imag(X), 'r');
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%6
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figure;
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plot(freq, real(X));
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%7
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figure;
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% fazove spektrum
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plot(freq, angle(X))
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[pks, locs] = findpeaks(magX, 'NPeaks', 10, 'SortStr', 'descend');
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f0 = freq(locs)
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f0b = f0(f0 < 100); % nyquistov teorem
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f0_ohranicene = f0b
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f0_ohranicene(f0_ohranicene < 2) = [];
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r = 0.975;
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b = 1;
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a = 1;
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for k = 1:length(f0_ohranicene)
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theta = 2*pi*(f0_ohranicene(k)/Fs);
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b = conv(b, [1, -2*cos(theta), 1]);
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a = conv(a, [1, -2*r*cos(theta), r^2]);
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end
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figure;
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zplane(b, a);
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title('Nuly a póly filtra');
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xlabel('Reálna časť');
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ylabel('Imaginárna časť');
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set(gcf, 'Color', 'none'); set(gca, 'Color', 'none');
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print('-depsc', 'fig1_semC.eps');
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figure;
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freqz(b, a);
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title('Frekvenčná charakteristika (1)');
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xlabel('Frekvencia [Hz]');
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ylabel('Zosilnenie [dB]');
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set(gcf, 'Color', 'none'); set(gca, 'Color', 'none');
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print('-depsc', 'fig2_semC.eps');
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figure;
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freqz(b, a);
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title('Frekvenčná charakteristika (2)');
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xlabel('Frekvencia [Hz]');
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ylabel('Zosilnenie [dB]');
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set(gcf, 'Color', 'none'); set(gca, 'Color', 'none');
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print('-depsc', 'fig3_semC.eps');
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filtered_data = filter(b, a, double(data));
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figure;
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plot(filtered_data);
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title('Filtrovaný signál');
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xlabel('Vzorky');
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ylabel('Amplitúda');
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grid on;
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set(gcf, 'Color', 'none'); set(gca, 'Color', 'none');
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set(gcf, 'PaperPosition', [0 0 1.7*6 0.75*4.2]);
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set(gcf, 'PaperSize', [1.7*6 0.75*4.2]);
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print('-depsc', 'fig4_semC.eps');
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