How to check if click is on scatter plot point with multiple markers (matplotlib)

Question

I have a scatter plot with multiple markers. How would I change the code so that it can still check if I click on a point on the graph or not. What would the variable

Answer 1

Of course the two scatter plots have to be stored in different variables. You may then also divide your annotations into two parts, those that belong to the first scatter, and those for the second. You would then loop over them and check if the event occurs in any of them.

import matplotlib.pyplot as plt
import numpy as np

x = np.arange(20)
y = np.sin(x)

fig, ax = plt.subplots()
line1 = ax.scatter(x[:10],y[:10],20, c="red", picker=True, marker='*')
line2 = ax.scatter(x[10:20],y[10:20],20, c="green", picker=True, marker='^')

ia = lambda i: plt.annotate("Annotate {}".format(i), (x[i],y[i]), visible=False)
img_annotations = [ia(i) for i in range(len(x))] 

lce = [False]
def show_ROI(event):
    tlce=False
    for annot, line in zip([img_annotations[:10],img_annotations[10:20]], [line1, line2]):
        if line.contains(event)[0]:
            lce[0]=tlce=True
            ind = line.contains(event)[1]["ind"]
            print('onpick3 scatter:', ind)
            ab = annot[ind[0]]
            ab.set_visible(True)
    if not tlce:
        for ab in img_annotations:
            ab.set_visible(False)
        lce[0] = False
    fig.canvas.draw_idle()

fig.canvas.mpl_connect('button_press_event', show_ROI)

plt.show()