36 lines
1.1 KiB
Matlab
36 lines
1.1 KiB
Matlab
function spectrogram(signal, samplingFreq, step_size, window_size)
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%%%%%%%%%%%%%%%%%%%%%%%
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%function spectrogram(signal, samplingFreq, step_size, window_size)
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% ex.: spectrogram(signal, 300, 50, 1000)
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%
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% Task: Plot the spectrogram of a given signal
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%
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% Inputs:
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% -signal: temporal signal to analyse
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% -samplingFreq: sampling frequency of the temporal signal
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% -step_size: how often the power spectrum will be computed in ms
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% -window_size: size of the analysing window in ms
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%
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% Ouput: None
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%
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% author: Guillaume Gibert (guillaume.gibert@ecam.fr)
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% date: 14/03/2023
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%%%%%%%%%%%%%%%%%%%%%%%
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figure;
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subplot(2,1,1);
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t=0:1/samplingFreq:length(signal)/samplingFreq-1/samplingFreq;
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plot(t, signal');
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xlim([0 length(signal)/samplingFreq-1/samplingFreq]);
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ylabel('Amplitude (norm. unit)');
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subplot(2,1,2);
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step = fix(step_size*samplingFreq/1000); % one spectral slice every step_size ms
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window = fix(window_size*samplingFreq/1000); % window_size ms data window
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[S, f, t] = specgram(signal);
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specgram(signal, 2^nextpow2(window), samplingFreq, window, window-step);
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xlabel('Time (s)');
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ylabel('Frequency (Hz)');
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title('hello'); |