How can I use the envelope function for the following plot?
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Hello!
I'm extremely new to Matlab and really need some help to implement my project!
How is it possible to smoothen the set of data on this plot- enclosed screen shot (initially it is a signal, .wav file)? I tried using envelope function, slmengine, hilbert but still of no use.
I also tried getting rid of the inf values and using filtering to make the further processing of the data easier.
Any help appreciated. My little code is below.
file = '/Users/mac/Desktop/clap101cm.wav';
[wave,Fs] = audioread(file);
sound(wave,Fs);
Nsamps = length(wave);
t = (1/Fs)*(1:Nsamps);
ydb = mag2db(wave);
new_sound = ydb(:,1);
smtlb = sgolayfilt(new_sound,3,11);
smtlb(isinf(smtlb))=NaN;
plot(t, smtlb);
windowSize =length(smtlb);
b = (1/windowSize)*ones(1,windowSize);
a = 1;
y = filter(b,a,smtlb);
hold on
plot(t,y)
grid on
xlabel('Time (s)')
ylabel('Amplitude, (dB)')
title('Clap decay.big')
Answers (1)
Image Analyst
on 4 Aug 2015
Edited: Image Analyst
on 4 Aug 2015
You forgot to attach your data in a .mat file. How about using sgolayfilt() if you have the Signal Processing Toolbox. It fits the data in a sliding window to a polynomial. You have control over the window size and polynomial order. There are other methods based on frequency like butterworth or Fourier filtering. It's a sound file - why do you need to smooth it?
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