import numpy
import matplotlib.pyplot as plt

N = 1000000
x = numpy.random.uniform( low=-1, high=1, size=[N, 1])
y = numpy.random.uniform( low=-1, high=1, size=[N, 1])

inside_bool = (x**2 + y**2) < 1

pi = 4 * numpy.sum(inside_bool) / N
print( pi )

x_in = x[inside_bool]
y_in = y[inside_bool]

plt.figure(figsize=[5, 5])
plt.scatter(x, y, s=1)
plt.scatter(x_in, y_in, color='r', s=1)
plt.show()