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- from sklearn.ensemble import GradientBoostingRegressor as GBSTR
- from sklearn.model_selection import cross_val_score,cross_val_predict
- from sklearn.model_selection import train_test_split
- from sklearn.preprocessing import StandardScaler
- from sklearn.metrics import mean_squared_error
- import matplotlib.pyplot as plt
- import numpy as np
- import pandas as pd
- # 导入数据
- data=pd.read_excel('model_optimize\data\data_filt.xlsx')
- x = data.iloc[:,1:10]
- y = data.iloc[:,-1]
- # 为 x 赋予列名
- x.columns = [
- 'organic_matter', # OM g/kg
- 'chloride', # CL g/kg
- 'cec', # CEC cmol/kg
- 'h_concentration', # H+ cmol/kg
- 'hn', # HN mg/kg
- 'al_concentration', # Al3+ cmol/kg
- 'free_alumina', # Free alumina g/kg
- 'free_iron', # Free iron oxides g/kg
- 'delta_ph' # ΔpH
- ]
- y.name = 'target_ph'
- Xtrain, Xtest, Ytrain, Ytest = train_test_split(x, y, test_size=0.2, random_state=42)
- score_5cv_all = []
- for i in np.arange(0.01, 0.5, 0.01):
- GBST = GBSTR(learning_rate=i)
- score_5cv = cross_val_score(GBST, Xtrain, Ytrain, cv=5).mean()
- score_5cv_all.append(score_5cv)
- pass
- score_max_5cv = max(score_5cv_all)
- n_lr_5cv = np.arange(0.01,0.5,0.01)[score_5cv_all.index(score_max_5cv)]
- print(
- "最大5cv得分:{}".format(score_max_5cv),
- "lr_5cv:{}".format(n_lr_5cv))
- # 随机种子
- score_5cv_all = []
- for i in range(0, 200, 1):
- GBST =GBSTR(learning_rate=n_lr_5cv
- ,random_state=i)
- score_5cv =cross_val_score(GBST, Xtrain, Ytrain, cv=5).mean()
- score_5cv_all.append(score_5cv)
- pass
- score_max_5cv = max(score_5cv_all)
- random_state_5cv = range(0, 200)[score_5cv_all.index(max(score_5cv_all))]
- print(
- "最大5cv得分:{}".format(score_max_5cv),
- "random_state_5cv:{}".format(random_state_5cv))
- #随机树数目
- score_5cv_all = []
- for i in range(1, 400, 1):
- GBST = GBSTR(n_estimators=i,
- learning_rate=n_lr_5cv,
- random_state=random_state_5cv)
- score_5cv = cross_val_score(GBST, Xtrain, Ytrain, cv=5).mean()
- score_5cv_all.append(score_5cv)
- pass
- score_max_5cv = max(score_5cv_all)
- n_est_5cv = range(1,400)[score_5cv_all.index(score_max_5cv)]
- print(
- "最大5cv得分:{}".format(score_max_5cv),
- "n_est_5cv:{}".format(n_est_5cv))
- score_5cv_all = []
- for i in range(1, 300, 1):
- GBST = GBSTR(n_estimators=n_est_5cv,
- learning_rate=n_lr_5cv,
- random_state=random_state_5cv,
- max_depth=i)
- score_5cv = cross_val_score(GBST, Xtrain, Ytrain, cv=5).mean()
- CV_predictions = cross_val_predict(GBST, Xtrain, Ytrain, cv=5)
- score_5cv_all.append(score_5cv)
- pass
- score_max_5cv = max(score_5cv_all)
- max_depth_5cv = range(1,300)[score_5cv_all.index(score_max_5cv)]
- print(
- "最大5cv得分:{}".format(score_max_5cv),
- "max_depth_5cv:{}".format(max_depth_5cv))
- score_5cv_all = []
- for i in np.arange(0.01,1.0,0.05):
- GBST = GBSTR(n_estimators=n_est_5cv,
- learning_rate=n_lr_5cv,
- random_state=random_state_5cv,
- max_depth=max_depth_5cv,
- alpha=i)
- score_5cv = cross_val_score(GBST, Xtrain, Ytrain, cv=5).mean()
- CV_predictions = cross_val_predict(GBST, Xtrain, Ytrain, cv=5)
- score_5cv_all.append(score_5cv)
- pass
- score_max_5cv = max(score_5cv_all)
- max_alpha_5cv = np.arange(0.01,1.0,0.05)[score_5cv_all.index(score_max_5cv)]
- print(
- "最大5cv得分:{}".format(score_max_5cv),
- "alpha_5cv:{}".format(max_alpha_5cv))
- # 固定参数
- GBST = GBSTR(learning_rate=n_lr_5cv,n_estimators=n_est_5cv,random_state=random_state_5cv,max_depth=max_depth_5cv,alpha = max_alpha_5cv)
- CV_score = cross_val_score(GBST, Xtrain, Ytrain, cv=5).mean()
- CV_predictions = cross_val_predict(GBST, Xtrain, Ytrain, cv=5)
- rmse1 = np.sqrt(mean_squared_error(Ytrain,CV_predictions))
- regressor = GBST.fit(Xtrain, Ytrain)
- test_predictions = regressor.predict(Xtest)
- score_test = regressor.score(Xtest,Ytest)
- rmse2 = np.sqrt(mean_squared_error(Ytest,test_predictions))
- print("5cv:",CV_score)
- print("rmse_5CV",rmse1)
- print("test:",score_test)
- print("rmse_test",rmse2)
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