1. GBDT + LR

from scipy.sparse.construct import hstack 
from sklearn.model_selection import train_test_split  

from sklearn.datasets.svmlight_format import load_svmlight_file 
from sklearn.ensemble.gradient_boosting import GradientBoostingClassifier 
from sklearn.linear_model.logistic import LogisticRegression 
from sklearn.metrics.ranking import roc_auc_score 
from sklearn.preprocessing.data import OneHotEncoder 
import numpy as np 
def gbdt_lr_train(libsvmFileName): 
 # load样本数据 
 X_all, y_all = load_svmlight_file(libsvmFileName) 
 # 训练/测试数据分割 
 X_train, X_test, y_train, y_test = train_test_split(X_all, y_all, test_size = 0.3, random_state = 42) 
 # 定义GBDT模型 
 gbdt = GradientBoostingClassifier(n_estimators=40, max_depth=3, verbose=0,max_features=0.5) 
 # 训练学习 
 gbdt.fit(X_train, y_train)
 # 预测及AUC评测 
 y_pred_gbdt = gbdt.predict_proba(X_test.toarray())[:, 1] 
 gbdt_auc = roc_auc_score(y_test, y_pred_gbdt) 
 print('gbdt auc: %.5f' % gbdt_auc) 
 # lr对原始特征样本模型训练 
 lr = LogisticRegression() 
 lr.fit(X_train, y_train) 
 # 预测及AUC评测 
 y_pred_test = lr.predict_proba(X_test)[:, 1] 
 lr_test_auc = roc_auc_score(y_test, y_pred_test) 
 print('基于原有特征的LR AUC: %.5f' % lr_test_auc) 
 # GBDT编码原有特征 
 X_train_leaves = gbdt.apply(X_train)[:,:,0] 
 X_test_leaves = gbdt.apply(X_test)[:,:,0] 
 # 对所有特征进行ont-hot编码 
 (train_rows, cols) = X_train_leaves.shape 
 gbdtenc = OneHotEncoder() 
 X_trans = gbdtenc.fit_transform(np.concatenate((X_train_leaves, X_test_leaves), axis=0)) 
 # 定义LR模型 
 lr = LogisticRegression() 
 # lr对gbdt特征编码后的样本模型训练 
 lr.fit(X_trans[:train_rows, :], y_train) 
 # 预测及AUC评测 
 y_pred_gbdtlr1 = lr.predict_proba(X_trans[train_rows:, :])[:, 1] 
 gbdt_lr_auc1 = roc_auc_score(y_test, y_pred_gbdtlr1) 
 print('基于GBDT特征编码后的LR AUC: %.5f' % gbdt_lr_auc1)  

 # 定义LR模型 lr = LogisticRegression(n_jobs=-1) 
 # 组合特征 X_train_ext = hstack([X_trans[:train_rows, :], X_train]) 
 X_test_ext = hstack([X_trans[train_rows:, :], X_test]) 
 print(X_train_ext.shape) 
 # lr对组合特征的样本模型训练 
 lr.fit(X_train_ext, y_train)
 # 预测及AUC评测 
 y_pred_gbdtlr2 = lr.predict_proba(X_test_ext)[:, 1] 
 gbdt_lr_auc2 = roc_auc_score(y_test, y_pred_gbdtlr2) 
 print('基于组合特征的LR AUC: %.5f' % gbdt_lr_auc2) 
if __name__ == '__main__': 
 gbdt_lr_train('data/sample_libsvm_data.txt') 

2. XGboost + LR

import xgboost as xgb 
from sklearn.datasets import load_svmlight_file 
from sklearn.model_selection import train_test_split 
from sklearn.linear_model import LogisticRegression 
from sklearn.metrics import roc_curve, auc, roc_auc_score 
from sklearn.externals import joblib 
import numpy as np 
from scipy.sparse import hstack 
from sklearn.preprocessing.data import OneHotEncoder 
def xgboost_lr_train(libsvmFileNameInitial): 
 # load样本数据 
 X_all, y_all = load_svmlight_file(libsvmFileNameInitial) 
 # 训练/测试数据分割 
 X_train, X_test, y_train, y_test = train_test_split(X_all, y_all, test_size = 0.3, random_state = 42)
 # 定义xgb模型 
 xgboost = xgb.XGBClassifier(nthread=4, learning_rate=0.08, n_estimators=50, max_depth=5, gamma=0, subsample=0.9, colsample_bytree=0.5) 
 # 训练xgb学习 
 xgboost.fit(X_train, y_train) 
 # 预测xgb及AUC评测 
 y_pred_test = xgboost.predict_proba(X_test)[:, 1] 
 xgb_test_auc = roc_auc_score(y_test, y_pred_test) 
 print('xgboost test auc: %.5f' % xgb_test_auc) 
 # xgboost编码原有特征 
 X_train_leaves = xgboost.apply(X_train) 
 X_test_leaves = xgboost.apply(X_test) 
 # 合并编码后的训练数据和测试数据 
 All_leaves = np.concatenate((X_train_leaves, X_test_leaves), axis=0)  

 All_leaves = All_leaves.astype(np.int32) 
 # 对所有特征进行ont-hot编码 
 xgbenc = OneHotEncoder() 
 X_trans = xgbenc.fit_transform(All_leaves) 
 (train_rows, cols) = X_train_leaves.shape 
 # 定义LR模型
 lr = LogisticRegression() 
 # lr对xgboost特征编码后的样本模型训练 
 lr.fit(X_trans[:train_rows, :], y_train) 
 # 预测及AUC评测 
 y_pred_xgblr1 = lr.predict_proba(X_trans[train_rows:, :])[:, 1] 
 xgb_lr_auc1 = roc_auc_score(y_test, y_pred_xgblr1) 
 print('基于Xgb特征编码后的LR AUC: %.5f' % xgb_lr_auc1) 
 # 定义LR模型 
 lr = LogisticRegression(n_jobs=-1) 
 # 组合特征 
 X_train_ext = hstack([X_trans[:train_rows, :], X_train]) 
 X_test_ext = hstack([X_trans[train_rows:, :], X_test]) 
 # lr对组合特征的样本模型训练 
 lr.fit(X_train_ext, y_train) 
 # 预测及AUC评测 
 y_pred_xgblr2 = lr.predict_proba(X_test_ext)[:, 1] 
 xgb_lr_auc2 = roc_auc_score(y_test, y_pred_xgblr2) 
 print('基于组合特征的LR AUC: %.5f' % xgb_lr_auc2) 
if __name__ == '__main__': 
 xgboost_lr_train("data/sample_libsvm_data.txt") 

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