text: from datasets import spiral
  import matplotlib.pyplot as plt
  
  x, t = spiral.load_data()
  print('x', x.shape)  # (300, 2)
  print('t', t.shape)  # (300, 3), one-hot encoded
  
  # plot datasets
  N = 100
  CLS_NUM = 3
  markers = ['o', 'x', '^']
  for i in range(CLS_NUM):
      plt.scatter(x[i * N:(i + 1) * N, 0],
                  x[i * N:(i + 1) * N, 1], s=40, marker=markers[i])
  plt.show()
  