用决策树对鸢尾花进行分类
def decision_iris(): """ 用决策树对鸢尾花进行分类 :return: """ # 1)获取数据集 iris = load_iris() # 2)划分数据集 x_train, x_test, y_train, y_test = train_test_split(iris.data, iris.target, random_state=22) # 3)决策树预估器 estimator = DecisionTreeClassifier(criterion="entropy") estimator.fit(x_train, y_train) # 4)模型评估 # 方法1:直接比对真实值和预测值 y_predict = estimator.predict(x_test) print("y_predict:\n", y_predict) print("直接比对真实值和预测值:\n", y_test == y_predict) # 方法2:计算准确率 score = estimator.score(x_test, y_test) print("准确率为:\n", score) # 可视化决策树 export_graphviz(estimator, out_file="iris_tree.dot", feature_names=iris.feature_names) return None