plotOnsets

maelzel.snd.features.plotOnsets(samples, sr, onsets, onsetbpf=None, samplesgain=20, envalpha=0.8, samplesalpha=0.4, onsetsalpha=0.3, figsize=None, offsets=None)[source]

Plot the results of onsets detection

Parameters:

  • samples (ndarray) – the samples from which onsets were detected

  • sr (int) – the sr of samples

  • onsets (ndarray) – the onsets as returned via onsetsRosita

  • onsetbpf (Optional[BpfBase]) – the onsetbpf as returned via onsetsRosita

  • samplesgain – a gain to apply to the samples for plotting

  • envalpha – alpha channel for onsets strength

  • samplesalpha – alpha channel for samples plot

  • onsetsalpha – alpha channel for onsets

  • offsets (Union[ndarray, list[float], None]) – if given, a region is plotted instead of a line. An offset of 0 indicates that the given onset has no offset and in this case also a line will be plotted

Return type:

None

Example

>>> from maelzel.snd.audiosample import Sample
>>> from maelzel.snd import features
>>> s = Sample("/path/to/sndfile.wav").getChannel(0)
>>> onsets, onsetstrength = features.onsets(s.samples, s.sr)
>>> features.plotOnsets(samples=s.samples, sr=s.sr, onsets=onsets,
...                     onsetbpf=onsetstrength)