MATLAB: How to plot actual amplitude on the colorbar using STFT (spectrogram)

actual amplitude/magnitudecolorbarspectrogramstft

I am using built in spectrogram function and it automatically plots the power/frequency (dB/Hz) values on the colorbar on the right.
Does anyone know how to plot actual amplitude/magnitude of a signal (A or V) on the colorbar using STFT (spectrogram)?
Thanks in advance,

Best Answer

If you read the help for spectrogram you'll find this:
    [...]  = spectrogram(...,SPECTRUMTYPE) uses the window scaling
    algorithm specified by SPECTRUMTYPE when computing the power spectral
    density matrix P.
    SPECTRUMTYPE can be set to 'psd' or 'power':
       'psd'   - returns the power spectral density.
       'power' - scales each estimate of the PSD by the equivalent noise
                bandwidth of the window (in Hz).  Use this option to
                obtain an estimate of the power at each frequency.
    The default value for SPECTRUMTYPE is 'psd'.
So just call spectrogram with its outputs and plot yourself:
[S,F,T,P] = spectrogram(your,inputs,sampling,frequency,and,window,etc);
pcolor(T,F,P),shading flat,colorbar
You can then chose whether get power spectral density or power.
HTH
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