From a1062222df02fca7cef7e60e91514802b575b85f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9mi=20BUSSIERE?= <remi.bussiere@ecam.fr>
Date: Wed, 19 Jul 2023 15:59:17 +0200
Subject: [PATCH] Ajouter 'signal_analysis.m'

---
 signal_analysis.m | 59 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 59 insertions(+)
 create mode 100644 signal_analysis.m

diff --git a/signal_analysis.m b/signal_analysis.m
new file mode 100644
index 0000000..3f94e92
--- /dev/null
+++ b/signal_analysis.m
@@ -0,0 +1,59 @@
+pkg load signal
+
+file_path = 'part1.wav';
+
+[x, Fs] = audioread(file_path);
+
+t = (0:length(x)-1) / Fs;
+
+
+
+subplot(2,2,1);
+plot(t, x);
+title('Time Domain - Original Signal');
+xlabel('Time (s)');
+ylabel('Amplitude');
+
+window = blackman(length(t));
+windowed_part = x .* window;
+
+subplot(2,2,2);
+plot(t, windowed_part)
+xlabel('Time (s)')
+ylabel('Amplitude')
+title('Blackman Window Applied')
+
+
+Nfir = 5;
+cutOffFrequency = 50;
+
+[B, A] = butter(Nfir,  cutOffFrequency/(Fs/2));
+
+filteredSignal = filter(B, A, windowed_cosine);
+
+
+
+subplot(2,2,3);
+plot(t, filteredSignal);
+xlabel('time (s)'); 
+ylabel('amplitude (a.u.)');
+title('IIR-Filtered signal')
+ 
+X = fft(filteredSignal);     % Compute FFT
+freq = (0:N-1) * (Fs/N);      % Frequency axis
+
+subplot(2,2,4);
+stem(freq, abs(X));
+title('Filtered Signal (Frequency Domain)');
+xlabel('Frequency (Hz)');
+ylabel('Magnitude');
+
+Z=roots(B);
+P=roots(A);
+figure
+zplane(Z,P);
+title ('Zeros and poles of the transsamplingFreqr function');
+legend('zeros','poles');
+grid on;
+
+frequencySpectrum(filteredSignal,Fs);