sklearn隨機森林準確性分數相同的訓練和測試數據

Question

我試圖建立一個電動汽車充電事件數據的分類模型。我想預測充電站是否可以在特定的時間點使用。我有下面的代碼工作：

from sklearn.ensemble import RandomForestClassifier 
import pandas as pd 

raw_data = pd.read_csv('C:/temp/sample_dataset.csv') 
raw_test = pd.read_csv('C:/temp/sample_dataset_test.csv') 
print ('raw data shape: ', raw_test.shape) 

#choose which columns to dummify 
X_vars = ['station_id', 'day_of_week', 'epoch', 'station_city', 
'station_county', 'station_zip', 'port_level', 'perc_local_occupancy', 
'ports_at_station', 'avg_charge_duration'] 
y_var = ['target_variable'] 
categorical_vars = ['station_id','station_city','station_county'] 

#split X and y in training and test 
X_train = raw_data.loc[:,X_vars] 
y_train = raw_data.loc[:,y_var] 
X_test = raw_test.loc[:,X_vars] 
y_test = raw_test.loc[:,y_var] 

#make dummy variables 
X_train = pd.get_dummies(X_train, columns = categorical_vars) 
X_test = pd.get_dummies(X_test, columns=categorical_vars) 

print('train size', X_train.shape, '\ntest size', X_test.shape) 

# Train uncalibrated random forest classifier on whole train and evaluate on test data 
clf = RandomForestClassifier(n_estimators=100, max_depth=2) 
clf.fit(X_train, y_train.values.ravel()) 

print ('RF accuracy: TRAINING', clf.score(X_train,y_train)) 
print ('RF accuracy: TESTING', clf.score(X_test,y_test)) 

結果

raw data shape: (1000000, 15) 
train size (1000000, 125) 
test size (1000000, 125) 
RF accuracy: TRAINING 0.831456 
RF accuracy: TESTING 0.831456 

我的問題是，爲什麼是訓練和測試精度完全一樣？我跑了很多次，總是一模一樣。有任何想法嗎？ （我已檢查確保原始數據不同）

Answer 1

那麼根本就在你的代碼一個錯字，因爲每次你選擇的所有行：

#split X and y in training and test 
X_train = raw_data.loc[:,X_vars] 
y_train = raw_data.loc[:,y_var] 
X_test = raw_test.loc[:,X_vars] 
y_test = raw_test.loc[:,y_var] 

您應該對其進行索引分別由一些指標，例如：X_train = raw_data.loc[:idx,X_vars]

Answer 2

您是否有可能在列車和測試文件中使用同一組數據？

如果數據相同，那麼最好將數據拆分爲train並使用train_test_split模塊進行測試。

http://scikit-learn.org/stable/modules/generated/sklearn.model_selection.train_test_split.html