import matplotlib
import matplotlib.pyplot as plt
from numpy import random, prod
from typing import List

number_of_samples = 4000
lower_bound = 0.997

units = (1 - lower_bound) * random.random_sample(size=number_of_samples) + lower_bound

probability: List[float] = []
for i in range(0, len(units)):
  probability.append(prod(units[0:i], initial=units[0]))

x = range(0, len(units))

plt.figure(figsize=[7, 10])
plt.subplot(2, 1, 1)
plt.plot(x[0:500], probability[0:500], color='green')
plt.title('Probability of a working system S')
plt.ylabel('Probability of success')
plt.grid()

plt.subplot(2, 1, 2)
plt.plot(x, probability)
plt.ylabel('Probability of success')
plt.grid()

plt.xlabel('Number of layers')

plt.savefig(f"graph_{lower_bound}.svg", format="svg")
plt.show()