code: def update(val):
      amp = samp.val
      freq = sfreq.val
      l.set_ydata(amp * np.sin(2 * np.pi * freq * t))
      fig.canvas.draw_idle()
  
imports: import matplotlib.pyplot
  import numpy
  from matplotlib.widgets import Button, Slider
label_desc: Use image node_id 1 for calling a global function with example usage: update(val) without return types