text: from bokeh.layouts import column
  from bokeh.models import CustomJS, ColumnDataSource, Slider
  from bokeh.plotting import Figure, output_file, show
  
  output_file("callback.html")
  
  x = [x*0.005 for x in range(0, 200)]
  y = x
  
  source = ColumnDataSource(data=dict(x=x, y=y))
  
  plot = Figure(plot_width=400, plot_height=400)
  plot.line('x', 'y', source=source, line_width=3, line_alpha=0.6)
  
  def callback(source=source, window=None):
      data = source.data
      f = cb_obj.value
      x, y = data['x'], data['y']
      for i in range(len(x)):
          y[i] = window.Math.pow(x[i], f)
      source.change.emit()
  
  slider = Slider(start=0.1, end=4, value=1, step=.1, title="power",
                  callback=CustomJS.from_py_func(callback))
  
  layout = column(slider, plot)
  
  show(layout)