final update
This commit is contained in:
parent
14d628bedb
commit
1ec3910671
Binary file not shown.
|
|
@ -1,2 +1,3 @@
|
||||||
# Midterm-DorianVELOSO
|
# Midterm-DorianVELOSO
|
||||||
|
|
||||||
|
With used codes and report
|
||||||
|
|
@ -0,0 +1,36 @@
|
||||||
|
function signal_win = blackmanWin(signal)
|
||||||
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
||||||
|
%function signal_win = blackmanWin(signal)
|
||||||
|
%
|
||||||
|
% Inputs:
|
||||||
|
% - signal: signal of interest
|
||||||
|
%
|
||||||
|
% Output:
|
||||||
|
% - signal_win: signal of interest on which a blackman window was applied
|
||||||
|
%
|
||||||
|
% Author: Guillaume Gibert, guillaume.gibert@ecam.fr
|
||||||
|
% Date: 15/03/2024
|
||||||
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
||||||
|
|
||||||
|
blackmanWin = zeros(1, length(signal));
|
||||||
|
for l_sample=1:length(signal)
|
||||||
|
blackmanWin(l_sample) = (0.42 - 0.5 * cos(2*pi*(l_sample)/length(signal)) + 0/08*cos(4*pi*(l_sample)/length(signal)));
|
||||||
|
end
|
||||||
|
|
||||||
|
% plot Blackman window
|
||||||
|
%~ figure;
|
||||||
|
%~ plot(blackmanWin);
|
||||||
|
|
||||||
|
% apply the Blackman window
|
||||||
|
for l_sample=1:length(signal)
|
||||||
|
signal_win(l_sample) = signal(l_sample) * blackmanWin(l_sample);
|
||||||
|
end
|
||||||
|
|
||||||
|
%~ figure;
|
||||||
|
%~ plot(signal);
|
||||||
|
%~ hold on;
|
||||||
|
%~ plot(signal_win);
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
@ -0,0 +1,61 @@
|
||||||
|
function power = frequencySpectrum(signal, fs, resolution)
|
||||||
|
%%%%%%%%%%%%%%%%%%
|
||||||
|
%function power = frequencySpectrum(signal, fs, pad)
|
||||||
|
%
|
||||||
|
% Task: Display the power spectrum (lin and log scale) of a given signal
|
||||||
|
%
|
||||||
|
% Input:
|
||||||
|
% - signal: the input signal to process
|
||||||
|
% - fs: the sampling rate in Hz
|
||||||
|
% - resolution: frequency resolution in Hz, signal will be padded with zeros if necessary
|
||||||
|
%
|
||||||
|
% Output:
|
||||||
|
% - power: the power spectrum
|
||||||
|
%
|
||||||
|
%
|
||||||
|
% Guillaume Gibert, guillaume.gibert@ecam.fr
|
||||||
|
% 15/03/2024
|
||||||
|
%%%%%%%%%%%%%%%%%%
|
||||||
|
|
||||||
|
n = length(signal); % number of samples
|
||||||
|
current_resolution = fs / n;
|
||||||
|
if (resolution < current_resolution)
|
||||||
|
n_original = n;
|
||||||
|
n = fs / resolution;
|
||||||
|
signal = [signal zeros(1, n-n_original)];
|
||||||
|
end
|
||||||
|
|
||||||
|
%~ if (pad)
|
||||||
|
%~ n_original = n;
|
||||||
|
%~ n = 2^(nextpow2(n));
|
||||||
|
%~ signal = [signal zeros(1, n-n_original)];
|
||||||
|
%~ end
|
||||||
|
|
||||||
|
y = fft(signal, n);% compute DFT of input signal
|
||||||
|
power = abs(y).^2/n; % power of the DFT
|
||||||
|
|
||||||
|
[val, ind] = max(power); % find the mx value of DFT and its index
|
||||||
|
|
||||||
|
% plots
|
||||||
|
figure;
|
||||||
|
|
||||||
|
subplot(1,3,1) % time plot
|
||||||
|
t=0:1/fs:(n-1)/fs; % time range
|
||||||
|
plot(t, signal)
|
||||||
|
xticks(0:0.1*fs:n*fs);
|
||||||
|
xticklabels(0:0.1:n/fs);
|
||||||
|
xlabel('Time (s)');
|
||||||
|
ylabel('Amplitude (a.u.)');
|
||||||
|
|
||||||
|
subplot(1,3,2) % linear frequency plot
|
||||||
|
f = (0:n-1)*(fs/n); % frequency range
|
||||||
|
plot(f,power, 'b*'); hold on;
|
||||||
|
plot(f,power, 'r');
|
||||||
|
xlabel('Frequency (Hz)')
|
||||||
|
ylabel('Power (a.u.)')
|
||||||
|
|
||||||
|
subplot(1,3,3) % log frequency plot
|
||||||
|
plot(f,10*log10(power/power(ind)));
|
||||||
|
xlabel('Frequency (Hz)')
|
||||||
|
ylabel('Power (dB)')
|
||||||
|
|
||||||
|
|
@ -0,0 +1,78 @@
|
||||||
|
%%%%%%%%%%%%%%%%%%%%%%
|
||||||
|
% UNKNOWN SIGNAL
|
||||||
|
% Sampling frequency: 200 Hz
|
||||||
|
% Duration; 2 s
|
||||||
|
% First second: 0.1Hz, 30 Hz, 30.5 Hz, 60 Hz, 61 Hz
|
||||||
|
% Second second: 0.1Hz, 32 Hz, 36 Hz, 64 Hz, 72 Hz
|
||||||
|
%%%%%%%%%%%%%%%%%%%%%%
|
||||||
|
|
||||||
|
% loads the signal package on Octave
|
||||||
|
%pkg load signal
|
||||||
|
|
||||||
|
% loads signal and its characteristics
|
||||||
|
signal = csvread('unknownsignal.csv');
|
||||||
|
|
||||||
|
%%%%%SIGNAL CHARACTERISTICS%%%%%
|
||||||
|
% sets sampling frequency
|
||||||
|
fps = 200; % -> freqMax of the signal should be < 150 Hz (Shannon-Nyquisit theorem), in practice freqMax < 60 Hz would be better
|
||||||
|
|
||||||
|
% computes the duration of the signal
|
||||||
|
duration = length(signal) / fps; % in s
|
||||||
|
|
||||||
|
% estimates its original frequency resolution
|
||||||
|
resolution = fps / length(signal); % in Hz
|
||||||
|
|
||||||
|
%%%%STATIONARITY%%%%%
|
||||||
|
% temporal plot
|
||||||
|
% figure;
|
||||||
|
% plot(signal);
|
||||||
|
% xticks(0:0.2*fps:length(signal)*fps);
|
||||||
|
% xticklabels(0:0.2:length(signal)/fps);
|
||||||
|
% xlabel('Time (s)');
|
||||||
|
% ylabel('Amplitude (a.u.)');
|
||||||
|
|
||||||
|
% spectrogram
|
||||||
|
step_size = 50; %ms
|
||||||
|
window_size = 100; %ms
|
||||||
|
% spectrogram(signal, fps, step_size, window_size);
|
||||||
|
|
||||||
|
% ccl: signal is not stationary, it is composed of 2 parts
|
||||||
|
|
||||||
|
%%%%%SPLIT SIGNAL INTO 2 PARTS%%%%%
|
||||||
|
% First part: [0 1s]
|
||||||
|
signal_1 = signal(1:end/2);
|
||||||
|
% Second part: [1s 2s]
|
||||||
|
signal_2 = signal(end/2+1:end);
|
||||||
|
|
||||||
|
% %%%%%SPECTRAL ANALYSIS (RECTANGULAR WINDOW)%%%%%
|
||||||
|
% %plots power spectrum with rectangular window
|
||||||
|
% % 1st part of the signal with 1 Hz resolution
|
||||||
|
% frequencySpectrum(signal_1, fps, 1);
|
||||||
|
% % 1st part of the signal with 0.5 Hz resolution
|
||||||
|
% frequencySpectrum(signal_1, fps, 0.5);
|
||||||
|
% %
|
||||||
|
% % 2nd part of the signal with 1 Hz resolution
|
||||||
|
% frequencySpectrum(signal_2, fps, 1);
|
||||||
|
% % 2nd part of the signal with 0.5 Hz resolution
|
||||||
|
% frequencySpectrum(signal_2, fps, 0.5);
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
%%%SPECTRAL ANALYSIS (BLACKMAN WINDOW)%%%%%
|
||||||
|
% % plots power spectrum with blackman window
|
||||||
|
% signal_1_win = blackmanWin(signal_1);
|
||||||
|
% % 1st part of the signal with 1 Hz resolution
|
||||||
|
% frequencySpectrum(signal_1_win, fps, 1);
|
||||||
|
% % 1st part of the signal with 0.5 Hz resolution
|
||||||
|
% frequencySpectrum(signal_1_win, fps, 0.5);
|
||||||
|
|
||||||
|
signal_2_win = blackmanWin(signal_2);
|
||||||
|
% 2nd part of the signal with 1 Hz resolution
|
||||||
|
frequencySpectrum(signal_2_win, fps, 1);
|
||||||
|
% 2nd part of the signal with 0.5 Hz resolution
|
||||||
|
frequencySpectrum(signal_2_win, fps, 0.5);
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
@ -0,0 +1,35 @@
|
||||||
|
function spectrogram(signal, samplingFreq, step_size, window_size)
|
||||||
|
%%%%%%%%%%%%%%%%%%%%%%%
|
||||||
|
%function spectrogram(signal, samplingFreq, step_size, window_size)
|
||||||
|
% ex.: spectrogram(signal, 300, 50, 1000)
|
||||||
|
%
|
||||||
|
% Task: Plot the spectrogram of a given signal
|
||||||
|
%
|
||||||
|
% Inputs:
|
||||||
|
% -signal: temporal signal to analyse
|
||||||
|
% -samplingFreq: sampling frequency of the temporal signal
|
||||||
|
% -step_size: how often the power spectrum will be computed in ms
|
||||||
|
% -window_size: size of the analysing window in ms
|
||||||
|
%
|
||||||
|
% Ouput: None
|
||||||
|
%
|
||||||
|
% author: Guillaume Gibert (guillaume.gibert@ecam.fr)
|
||||||
|
% date: 14/03/2023
|
||||||
|
%%%%%%%%%%%%%%%%%%%%%%%
|
||||||
|
|
||||||
|
figure;
|
||||||
|
subplot(2,1,1);
|
||||||
|
t=0:1/samplingFreq:length(signal)/samplingFreq-1/samplingFreq;
|
||||||
|
plot(t, signal');
|
||||||
|
xlim([0 length(signal)/samplingFreq-1/samplingFreq]);
|
||||||
|
ylabel('Amplitude (norm. unit)');
|
||||||
|
|
||||||
|
subplot(2,1,2);
|
||||||
|
step = fix(step_size*samplingFreq/1000); % one spectral slice every step_size ms
|
||||||
|
window = fix(window_size*samplingFreq/1000); % window_size ms data window
|
||||||
|
|
||||||
|
|
||||||
|
[S, f, t] = specgram(signal);
|
||||||
|
specgram(signal, 2^nextpow2(window), samplingFreq, window, window-step);
|
||||||
|
xlabel('Time (s)');
|
||||||
|
ylabel('Frequency (Hz)');
|
||||||
File diff suppressed because one or more lines are too long
Loading…
Reference in New Issue