Function mse

recommenders/itembased.py:162–165

(p, t)

# calculate accuracy
def mse(p, t):
  p = np.array(p)
  t = np.array(t)
  return np.mean((p - t)**2)

print('train mse:', mse(train_predictions, train_targets))
print('test mse:', mse(test_predictions, test_targets))