Tkinter & matplotlib

[Larz60+]

OK, now that My code copy is correct, I added some debugging printouts as follows:

import tkinter
from tkinter import *
 
from matplotlib.backends.backend_tkagg import *
from matplotlib.backend_bases import key_press_handler
from matplotlib.figure import Figure
from matplotlib import pyplot as plt
from matplotlib import animation
 
import numpy as np
from scipy.special import comb
 
 
def inputik():
    global nPoints
    fig.clear("all")
    nPoints = int(pocetbodu_entry.get())
    pocetbodu_entry.delete(0, "end")
    vykresleni()
 
def bernstein_poly(i, n, t):
    """
     Bernsteinův polynom
     t ... parametr
     n ... počet bodů
     i ... (počet bodů - 1)
 
    """
 
    return comb(n, i) * ( t**(n-i) ) * (1 - t)**i
 
 
def bezier_curve(points, nTimes=1000):
    """
       Ze zadaných bodů a kroku sestrojí bezierovu křivku
    """
 
    nPoints = len(points)
    xPoints = np.array([p[0] for p in points])
    yPoints = np.array([p[1] for p in points])
 
    t = np.linspace(0.0, 1.0, nTimes)
 
    polynomial_array = np.array([ bernstein_poly(i, nPoints-1, t) for i in range(0, nPoints)   ])
 
    xvals = np.dot(xPoints, polynomial_array)
    yvals = np.dot(yPoints, polynomial_array)
 
    return xvals, yvals
 
 
def vykresleni():
 
    if __name__ == "__main__":
        from matplotlib import pyplot as plt
        global ax1
 
        #nPoints = (pocetbodu_entry.get())
        points = np.random.rand(nPoints, 2) * 200
        xpoints = [p[0] for p in points]
        ypoints = [p[1] for p in points]
 
 
        xvals, yvals = bezier_curve(points, nTimes=1000)
 
        print(f"\nPoints")
        for x, y in points:
            print(f"x: {x:20}, y: {y:20}")
        print()

        ax1 = fig.add_subplot(111).plot(xvals, yvals)
        ax2 = fig.add_subplot(111).plot(xpoints, ypoints, "ro")
        for nr in range(len(points)):
            print(f"nr: {nr}, points[nr][0]: {points[nr][0]}, points[nr][1]: {points[nr][1]}")
            ax2.text(points[nr][0], points[nr][0], nr)
 
        for i in range(nPoints-1):
            pomocna_1x = [xpoints[i], xpoints[i+1]]
            pomocna_1y = [ypoints[i], ypoints[i+1]]
            ax3=fig.add_subplot(111).plot(pomocna_1x, pomocna_1y,'b--', linewidth=2)
 
 
        canvas.draw()
 
 
# canvas a vykreslovací ploška
 
root = tkinter.Tk()
root.wm_title("Beziereček")
 
 
fig = plt.Figure(figsize=(5, 4), dpi=100, frameon=False)
canvas = FigureCanvasTkAgg(fig, master=root)  # A tk.DrawingArea.
canvas.get_tk_widget().pack(side=tkinter.TOP, fill=tkinter.BOTH, expand=1)
 
toolbar = NavigationToolbar2Tk(canvas, root)
toolbar.update()
canvas.get_tk_widget().pack(side=tkinter.TOP, fill=tkinter.BOTH, expand=1)
 
 
def on_key_press(event):
    print("you pressed {}".format(event.key))
    key_press_handler(event, canvas, toolbar)
 
 
canvas.mpl_connect("key_press_event", on_key_press)
 
 
def konec():
    root.quit()
    root.destroy()
 
 
#tlačítka a blbítka
 
pocetbodu = Label(root, text = "Počet řídících bodů: ")
pocetbodu_entry = Entry(root)
buttonQuit = Button(master=root, text="Quit", command=konec)
buttonQuit.pack(side=tkinter.BOTTOM)
buttonSubmit = Button(master=root, text="Submit", command=inputik)
buttonSubmit.pack(side=tkinter.BOTTOM)
pocetbodu_entry.pack(side=tkinter.BOTTOM)
pocetbodu.pack(side=tkinter.BOTTOM)
 
 
 
tkinter.mainloop()

which quickly exposed what I think is part the problem.
your line 69 reads ax2.text(points[nr][0], points[nr][0], nr)
and I think it should be: ax2.text(points[nr][0], points[nr][1], nr)

There are still some issues
Is that correct?