click_test.py

#!/usr/bin/env python
import numpy as np
import matplotlib.pyplot as plt
from scipy.integrate import trapz


# Simple mouse click function to store coordinates
def onclick(event):
    global ix, iy
    ix, iy = event.xdata, event.ydata

    print(ix.iy)

    # assign global variable to access outside of function
    global coords
    coords.append((ix, iy))

    if len(coords) == 2:
        fig.canvas.mpl_disconnect(cid)
    return

x = np.arange(-10,10)
y = x**2

fig = plt.figure(1)
ax = fig.add_subplot(111)
ax.plot(x,y)

coords = []

# Call click func
cid = fig.canvas.mpl_connect('button_press_event', onclick)

plt.show(1)

# limits for integration
ch1 = np.where(x == (find_nearest(x, coords[0][0])))
ch2 = np.where(x == (find_nearest(x, coords[1][0])))