线性回归模型
plt.clf()plt.scatter(ages_train, net_worths_train, color="b", label="train data")plt.scatter(ages_test, net_worths_test, color="r", label="test data")plt.plot(ages_test, reg.predict(ages_test), color="black")plt.legend(loc=2)plt.xlabel("ages")plt.ylabel("net worths")

