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  • 决策树进阶:随机森林模型

     1 from sklearn import tree,datasets
     2 from sklearn.model_selection import train_test_split
     3 wine=datasets.load_wine()
     4 X,y=wine.data[:,:2],wine.target
     5 X_train,X_test,y_train,y_test=train_test_split(X,y,random_state=3)
     6 
     7 from sklearn.ensemble import RandomForestClassifier
     8 forest=RandomForestClassifier(n_estimators=6,random_state=3)
     9 forest.fit(X_train,y_train)
    10 print("the score of this model:{}".format(forest.score(X_test,y_test)))
     1 from matplotlib.colors import ListedColormap
     2 cmap_light=ListedColormap(['#FFAAAA','#AAFFAA','#AAAAFF'])
     3 cmap_bold=ListedColormap(['#FF0000','#00FF00','#0000FF'])
     4 
     5 import numpy as np
     6 from matplotlib import pyplot as plt
     7 x_min=X_train[:,0].min()-1
     8 x_max=X_train[:,0].max()+1
     9 y_min=X_train[:,1].min()-1
    10 y_max=X_train[:,1].max()+1
    11 xx,yy=np.meshgrid(np.arange(x_min,x_max,.02),
    12                   np.arange(y_min,y_max,.02))
    13 z=forest.predict(np.c_[xx.ravel(),yy.ravel()])
    14 z=z.reshape(xx.shape)
    15 plt.figure()
    16 plt.pcolormesh(xx,yy,z,cmap=cmap_light)
    17 #plt.pcolormesh(xx,yy,z,cmap=plt.cm.Pastel1)
    18 plt.scatter(X[:,0],X[:,1],c=y,cmap=cmap_bold,edgecolors='k',s=20)
    19 plt.xlim(xx.min(),xx.max())
    20 plt.ylim(yy.min(),yy.max())
    21 plt.title("Random Forest(n_estimators=6)")
    22 plt.show()
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  • 原文地址:https://www.cnblogs.com/St-Lovaer/p/12294496.html
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