In the documentation -
s = spectrogram(signal) and
spectrogram(signal) are two commands to plot the spectrogram. However, the variable
s is complex valued. I am unable to understand which output of the
spectrogram is used to generate the image plot?
Question 2) How to determine the best values of the parameters
noverlap ? Should
noverlap be 50% of the signal length (number of elements in the time series) or 90% etc? What if it is zero then what does it mean? My dataset has sampling time = 1sec. I remember reading somewhere that the window should be at least roughly twice as long as the period of the lowest frequency. So, for my case is
w=2 since frequency = 1?
I was thinking of using
pspectrum(signal,'spectrogram') which outputs the spectrogram and use the output values as inputs to the
spectrogram() function. But again, I don't know which output values from
pspectrum can be used, if at all that is possible.