Spectrogram
Spectrogram
Spectrogram[list]
plots the spectrogram of list.
Spectrogram[list,n]
uses partitions of length n.
Spectrogram[list,n,d]
uses partitions with offset d.
Spectrogram[list,n,d,wfun]
applies a smoothing window wfun to each partition.
Spectrogram[list,n,d,wfun,m]
pads partitions with zeros to length m prior to the computation of the transform.
Spectrogram[audio,…]
plots the spectrogram of audio.
Spectrogram[video]
plots the spectrogram of the first audio track in video.
Details and Options
- Spectrogram is also known as time-frequency plot.
- A spectrogram is a common visualization technique that shows how the frequency content of a signal changes over time.
- Spectrogram plots the magnitude of the short-time Fourier transform (STFT), computed as a discrete Fourier transform (DFT) of partitions of data.
- Compute the short-time Fourier transform of list using ShortTimeFourier.
- Spectrogram[list] uses partitions of length
and offset 
, where m is Length[list]. - The partition length n and offset d can be expressed as an integer number (interpreted as number of samples) or as time or sample quantities.
- If necessary, fixed padding is used on the right to make all the partitions the same size.
- Spectrogram displays only the first half of the magnitude of the discrete Fourier transform due to the symmetry property of the transform.
- In Spectrogram[list,n,d,wfun], the smoothing window wfun can be specified using a window function that will be sampled between
and 
or a list of length n. The default window is DirichletWindow, which effectively does no smoothing. - Spectrogram works with numeric lists as well as Audio and Sound objects.
- For multichannel sound objects, the spectrogram is computed over the sum of all channels.
- Spectrogram accepts all ArrayPlot options with the following additions and changes: [List of all options]
-
AspectRatio 1/3 ratio of height to width ColorFunction Automatic how each cell should be colored FrameTicks Automatic what ticks to include on the frame MaxPlotPoints Automatic the maximum number of points to include Method