Interactive and clickable plots using Panel, Holoviz and Bokeh in Jupyter Notebooks

interactive_audio_plots.py

import numpy as np
import panel as pn
import holoviews as hv 
hv.extension("bokeh")
# hv.extension('matplotlib')
from holoviews.streams import Stream, Params
from scipy.io import wavfile
from scipy.signal import spectrogram

rate, data = wavfile.read('/filepath.wav')
width = 1000
audio = pn.pane.Audio(data, sample_rate=rate, name='Audio', throttle=500)
time = np.linspace(0, len(data) / rate, num=len(data))
line_plot = hv.Curve((time, data), ["time (s)","amplitude"]).opts(width=width)
f, t, sxx = spectrogram(data, rate)
spec_gram = hv.Image((t, f, np.log10(sxx)), ["time (s)","frequency (hz)"]).opts(width=width)

def interactive_play(x,y,t):
    if x is None:
        return hv.VLine(t).opts(color='green')
    else:
        audio.time = x
        return hv.VLine(x).opts(color='green')

stream = Params(parameters=[audio.param.time], rename={'time': 't'})
tap = hv.streams.SingleTap(transient=True)
dmap_time = hv.DynamicMap(interactive_play, streams=[stream, tap])

pn.Column( audio, (spec_gram * dmap_time), (line_plot * dmap_time))

Minor suggestions for simplification:

1. You only need either pn.extension or hv.extension, i.e. hv.extension("bokeh") should be sufficient.

2. You can now use pn.depends or param.depends to declare DynamicMap callbacks:

tap = hv.streams.SingleTap(transient=True)

@pn.depends(x=tap.param.x, y=tap.param.y, t=audio.param.time) 
def interactive_play(x, y, t):
    if x is None:
        return hv.VLine(t).opts(color='green')
    else:
        audio.time = x
        return hv.VLine(x).opts(color='green')

dmap_time = hv.DynamicMap(interactive_play)

Thanks @philippjfr, I've tried your suggestions and the #2 decorator strangely stops the tap event from working.
I removed audio.param.time to simplify things

This works:

tap = hv.streams.SingleTap(x=0, y=0, transient=True)
def interactive_play(x,y):
    return hv.VLine(x).opts(color='green')
dmap_time = hv.DynamicMap(interactive_play, streams=[tap])

This doesn't:

tap = hv.streams.SingleTap(x=0, y=0, transient=True)
@pn.depends(x=tap.param.x, y=tap.param.y) 
def interactive_play(x,y):
    return hv.VLine(x).opts(color='green')
dmap_time = hv.DynamicMap(interactive_play)

I'm sure there's something obvious I'm missing. Should that above code work or is there something I'm doing wrong?

Hmm, odd, which version of HoloViews do you have?

which version of HoloViews do you have

import holoviews as hv
hv.__version__
>>> '1.13.2'

Thanks for this wonderful idea and code. I'm able to plot the spectrogram and audio, however the audio doesn't seem to play.

Strangely, it works for normal display audio though. I'm using holoviews version '1.14.2a5' and jupyter lab.
Any suggestions?

There is a related issue, pane Audio is broken for np.array waveform input. Downgrading to panel==0.10.3 solved the issue where audio doesn't seem to play for me.

I tried this but the vertical line is not sliding as the audio is being played. Any ideas what could be the reason?