plot a smooth envelope for oscillation curves
34 visualizzazioni (ultimi 30 giorni)
Mostra commenti meno recenti
Hello, everyone, I would like to plot a smooth envelope for a oscillation curve. It seems that the function 'envelope' in MATLAB can be used to plot a envelope curve. But I cannot obtain a smooth envelope based on this function. Would anyone help me about this envelope curve? Following is the source data. Thanks.
[up,dw]=envelope(y,100,'analytic'); figure,plot(x,[up;dw])
[up,dw]=envelope(y,100,'peak'); figure,plot(x,[y;up;dw])
This is the kind of smooth envelope curve I want to obtain.
0 Commenti
Risposta accettata
Greg Dionne
il 10 Ago 2018
Do you have a particular selection criteria for the peaks or formula for how you would like the smoothing performed at the extremities?
I ran a spectrogram on your signal to see if there was a simple envelope to extract. It appears that there is, so maybe you could try to extract the amplitude ridges. (It seems a little bit of aliasing is in your sampled signal as well. Not sure if it's important, but have a look)
spectrogram(y,kaiser(256,40),250,[],1/mean(diff(x)),'power','yaxis')
I tried to extract a few ridges:
[sst,f] = fsst(y,1/mean(diff(x)),kaiser(256,10));
fridge = tfridge(sst,f,10,'NumRidges',6);
plot(x,fridge)
I got a reasonable hit on the fundamental, so perhaps you could attempt to extract the spectrum amplitudes along those frequencies to get a good sense of the power envelope.
Più risposte (1)
Vedere anche
Prodotti
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!