text: import numpy as np
  
  import matplotlib.pyplot as plt
  
  from O3 import xor_dataset
  
  np.random.seed(1)
  
  X_xor, y_xor = xor_dataset()
  
  plt.scatter(X_xor[y_xor == 1, 0], X_xor[y_xor == 1, 1],
              c='blue', marker='x', label='1')
  
  plt.scatter(X_xor[y_xor == -1, 0], X_xor[y_xor == -1, 1],
              c='red', marker='s', label='-1')
  
  plt.xlim([-3, 3])
  plt.ylim([-3, 3])
  
  plt.legend(loc='upper left')
  plt.tight_layout()
  plt.show()
  