from fastplotlib.graphics.selectors.linear import LinearSelector
from fastplotlib import Plot
import numpy as np
from ipywidgets import VBox

ls = LinearSelector((0, 100), 300, (0, 0))

plot1 = Plot()

xs = np.linspace(0, 400, 1000)
sine = np.sin(xs) * 100

sg = plot1.add_line(sine)
plot1.add_graphic(ls)

plot2 = Plot()
zoomed = plot2.add_line(np.zeros(100))

def set_zoom_plot(ev):
    bounds = ev.pick_info["new_data"]
    
    zoomed.data = sg.data()[100:200]
    zoomed.data= sg.data()[bounds[0]:bounds[1]]
    plot2.auto_scale()


ls.bounds.add_event_handler(set_zoom_plot)

VBox([plot1.show(), plot2.show()])