import numpy as np
import matplotlib.pyplot as plt

n = 1500
x = 1-2*np.random.random(int(n))
y = 1-2*np.random.random(int(n))
insideX, insideY = x[(x*x + y*y) <= 1], y[(x*x + y*y) <= 1]
outsideX, outsideY = x[(x*x + y*y) > 1], y[(x*x + y*y) > 1]

circle = plt.Circle((0, 0), 1, color='orange', fill=False)

fig, ax = plt.subplots(1)
ax.set_xlim(-1.1, 1.1)
ax.set_ylim(-1.1, 1.1)
ax.set_aspect('equal', 'box')

ax.add_patch(circle)

plt.savefig('circle-raw.png', bbox_inches='tight')

ax.scatter(insideX, insideY, color= 'black')
ax.scatter(outsideX, outsideY, color= 'black')

plt.savefig('circle-black.png', bbox_inches='tight')

ax.scatter(insideX, insideY, color= 'red')
ax.scatter(outsideX, outsideY, color= 'blue')
plt.savefig('circle-classified.png', bbox_inches='tight')