librosa.display.waveplot

librosa.display.waveplot(y, sr=22050, max_points=50000.0, x_axis='time', offset=0.0, max_sr=1000, ax=None, **kwargs)[source]

Plot the amplitude envelope of a waveform.

If y is monophonic, a filled curve is drawn between [-abs(y), abs(y)].

If y is stereo, the curve is drawn between [-abs(y[1]), abs(y[0])], so that the left and right channels are drawn above and below the axis, respectively.

Long signals (duration >= max_points) are down-sampled to at most max_sr before plotting.

Parameters
ynp.ndarray [shape=(n,) or (2,n)]

audio time series (mono or stereo)

srnumber > 0 [scalar]

sampling rate of y

max_pointspostive number or None

Maximum number of time-points to plot: if max_points exceeds the duration of y, then y is downsampled.

If None, no downsampling is performed.

x_axisstr or None

Display of the x-axis ticks and tick markers. Accepted values are:

  • ‘time’markers are shown as milliseconds, seconds, minutes, or hours.

    Values are plotted in units of seconds.

  • ‘s’ : markers are shown as seconds.

  • ‘ms’ : markers are shown as milliseconds.

  • ‘lag’ : like time, but past the halfway point counts as negative values.

  • ‘lag_s’ : same as lag, but in seconds.

  • ‘lag_ms’ : same as lag, but in milliseconds.

  • None, ‘none’, or ‘off’: ticks and tick markers are hidden.

axmatplotlib.axes.Axes or None

Axes to plot on instead of the default plt.gca().

offsetfloat

Horizontal offset (in seconds) to start the waveform plot

max_srnumber > 0 [scalar]

Maximum sampling rate for the visualization

kwargs

Additional keyword arguments to matplotlib.pyplot.fill_between

Returns
pcmatplotlib.collections.PolyCollection

The PolyCollection created by fill_between.

Examples

Plot a monophonic waveform

>>> import matplotlib.pyplot as plt
>>> y, sr = librosa.load(librosa.ex('choice'), duration=10)
>>> fig, ax = plt.subplots(nrows=3, sharex=True, sharey=True)
>>> librosa.display.waveplot(y, sr=sr, ax=ax[0])
>>> ax[0].set(title='Monophonic')
>>> ax[0].label_outer()

Or a stereo waveform

>>> y, sr = librosa.load(librosa.ex('choice', hq=True), mono=False, duration=10)
>>> librosa.display.waveplot(y, sr=sr, ax=ax[1])
>>> ax[1].set(title='Stereo')
>>> ax[1].label_outer()

Or harmonic and percussive components with transparency

>>> y, sr = librosa.load(librosa.ex('choice'), duration=10)
>>> y_harm, y_perc = librosa.effects.hpss(y)
>>> librosa.display.waveplot(y_harm, sr=sr, alpha=0.25, ax=ax[2])
>>> librosa.display.waveplot(y_perc, sr=sr, color='r', alpha=0.5, ax=ax[2])
>>> ax[2].set(title='Harmonic + Percussive')

(Source code)

../_images/librosa-display-waveplot-1.png