61 lines
776 B
Mathematica
61 lines
776 B
Mathematica
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clear;
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% exercice 1
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f1 = 1000;
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f2 = 3000;
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N = 100;
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Fe = 10000;
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Te = 1/Fe;
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T = [0:Te:(N-1)*Te];
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Y1 = cos(2*pi*f1 * T);
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Y2 = cos(2*pi*f2 * T);
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Ys = Y1 + Y2;
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% plot(T, Ys);
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% hold;
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% fft discrète
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% semilogy([0:N-1]/N*Fe, abs(fft(Ys, N)));
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% exercice 2
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fc_tild = 1000/Fe;
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A = 1;
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ordre = 10;
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B = 2*fc_tild * sinc(2*fc_tild * [-ordre/2:1:ordre/2]);
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%plot(B);
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%hold;
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ordre = 60;
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B = 2*fc_tild * sinc(2*fc_tild * [-ordre/2:1:ordre/2]);
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%plot(B);
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% exercice 3
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fc_tild = 1000/Fe;
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A = 1;
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ordre = 10;
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B = 2*fc_tild*sinc(2*fc_tild * [-ordre/2:1:ordre/2]);
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Yf = filter( B, A, Ys);
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semilogy([0:N-1]/N*Fe, abs(fft(Yf, N)));
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hold;
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ordre = 60;
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B = 2*fc_tild*sinc(2*fc_tild * [-ordre/2:1:ordre/2]);
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Yf = filter( B, A, Ys);
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semilogy([0:N-1]/N*Fe, abs(fft(Ys, N)));
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legend;
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