波士顿房价预测

import numpy as np
import matplotlib as mpl
import matplotlib.pyplot as plt
from sklearn.model_selection import train_test_split
from sklearn.linear_model import ElasticNetCV
import sklearn.datasets
from pprint import pprint
from sklearn.preprocessing import PolynomialFeatures, StandardScaler
from sklearn.pipeline import Pipeline
from sklearn.metrics import mean_squared_error
from sklearn.ensemble import RandomForestRegressor
import warnings
def not_empty(s): return s != ''
if __name__ == "__main__": data = sklearn.datasets.load_boston() x = np.array(data.data) y = np.array(data.target) print('样本个数：%d, 特征个数：%d' % x.shape) print(y.shape) y = y.ravel() x_train, x_test, y_train, y_test = train_test_split(x, y, train_size=0.7, random_state=0) model = Pipeline([ ('ss', StandardScaler()), ('poly', PolynomialFeatures(degree=3, include_bias=True)), ('linear', ElasticNetCV(l1_ratio=[0.1, 0.3, 0.5, 0.7, 0.99, 1], alphas=np.logspace(-3, 2, 5), fit_intercept=False, max_iter=1e3, cv=3)) ]) # model = RandomForestRegressor(n_estimators=50, criterion='mse') print('开始建模...') model.fit(x_train, y_train) linear = model.get_params('linear')['linear'] print(u'超参数：', linear.alpha_) print(u'L1 ratio：', linear.l1_ratio_) print(u'系数：', linear.coef_.ravel()) order = y_test.argsort(axis=0) y_test = y_test[order] x_test = x_test[order, :] y_pred = model.predict(x_test) r2 = model.score(x_test, y_test) mse = mean_squared_error(y_test, y_pred) print('R2:', r2) print('均方误差：', mse) t = np.arange(len(y_pred)) mpl.rcParams['font.sans-serif'] = ['simHei'] mpl.rcParams['axes.unicode_minus'] = False plt.figure(facecolor='w') plt.plot(t, y_test, 'r-', lw=2, label='真实值') plt.plot(t, y_pred, 'g-', lw=2, label='估计值') plt.legend(loc='best') plt.title('波士顿房价预测', fontsize=18) plt.xlabel('样本编号', fontsize=15) plt.ylabel('房屋价格', fontsize=15) plt.grid() plt.show()


  

 

  
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超参数： 0.31622776601683794
L1 ratio： 0.99
R2: 0.7722034192609936
均方误差： 18.967596568189173

使用RandomForestRegressor

R2: 0.7986958266918252
均方误差： 16.761692973684216

文章来源: maoli.blog.csdn.net，作者：刘润森！，版权归原作者所有，如需转载，请联系作者。

原文链接：maoli.blog.csdn.net/article/details/89457444