#申明,本文章参考于 https://blog.csdn.net/yeoman92/article/details/75051848
import numpy as np import matplotlib.pyplot as plt # 生成数据 def gen_data(x1, x2): y = np.sin(x1) * 1/2 + np.cos(x2) * 1/2 + 0.1 * x1 return y def load_data(): x1_train = np.linspace(0, 50, 500) x2_train = np.linspace(-10, 10, 500) data_train = np.array([[x1, x2, gen_data(x1, x2) + np.random.random(1) - 0.5] for x1, x2 in zip(x1_train, x2_train)]) x1_test = np.linspace(0, 50, 100) + np.random.random(100) * 0.5 x2_test = np.linspace(-10, 10, 100) + 0.02 * np.random.random(100) data_test = np.array([[x1, x2, gen_data(x1, x2)] for x1, x2 in zip(x1_test, x2_test)]) return data_train, data_test train, test = load_data() # train的前两列是x,后一列是y,这里的y有随机噪声 x_train, y_train = train[:, :2], train[:, 2] x_test, y_test = test[:, :2], test[:, 2] # 同上,但这里的y没有噪声 # 回归部分 def try_different_method(model, method): model.fit(x_train, y_train) score = model.score(x_test, y_test) result = model.predict(x_test) plt.figure() plt.plot(np.arange(len(result)), y_test, "go-", label="True value") plt.plot(np.arange(len(result)), result, "ro-", label="Predict value") plt.title(f"method:{method}---score:{score}") plt.legend(loc="best") plt.show() # 方法选择 # 1.决策树回归 from sklearn import tree model_decision_tree_regression = tree.DecisionTreeRegressor() # 2.线性回归 from sklearn.linear_model import LinearRegression model_linear_regression = LinearRegression() # 3.SVM回归 from sklearn import svm model_svm = svm.SVR() # 4.kNN回归 from sklearn import neighbors model_k_neighbor = neighbors.KNeighborsRegressor() # 5.随机森林回归 from sklearn import ensemble model_random_forest_regressor = ensemble.RandomForestRegressor(n_estimators=20) # 使用20个决策树 # 6.Adaboost回归 from sklearn import ensemble model_adaboost_regressor = ensemble.AdaBoostRegressor(n_estimators=50) # 这里使用50个决策树 # 7.GBRT回归 from sklearn import ensemble model_gradient_boosting_regressor = ensemble.GradientBoostingRegressor(n_estimators=100) # 这里使用100个决策树 # 8.Bagging回归 from sklearn import ensemble model_bagging_regressor = ensemble.BaggingRegressor() # 9.ExtraTree极端随机数回归 from sklearn.tree import ExtraTreeRegressor model_extra_tree_regressor = ExtraTreeRegressor()