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Parent(s):
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Browse files- .streamlit/config.toml +2 -0
- LICENSE +201 -0
- LightGBM 调参.md +402 -0
- app.py +135 -0
- definitions.py +24 -0
- git.sh +3 -0
- requirements.txt +6 -0
.streamlit/config.toml
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[deprecation]
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showPyplotGlobalUse = False
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LICENSE
ADDED
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LightGBM 调参.md
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1 |
+
**Step1. 学习率和估计器及其数目**
|
2 |
+
|
3 |
+
不管怎么样,我们先把学习率先定一个较高的值,这里取 `learning_rate = 0.1`,其次确定估计器`boosting/boost/boosting_type`的类型,不过默认都会选`gbdt`。
|
4 |
+
|
5 |
+
为了确定估计器的数目,也就是boosting迭代的次数,也可以说是残差树的数目,参数名为`n_estimators/num_iterations/num_round/num_boost_round`。我们可以先将该参数设成一个较大的数,然后在cv结果中查看最优的迭代次数,具体如代码。
|
6 |
+
|
7 |
+
在这之前,我们必须给其他重要的参数一个初始值。初始值的意义不大,只是为了方便确定其他参数。下面先给定一下初始值:
|
8 |
+
|
9 |
+
以下参数根据具体项目要求定:
|
10 |
+
|
11 |
+
```
|
12 |
+
'boosting_type'/'boosting': 'gbdt'
|
13 |
+
'objective': 'regression'
|
14 |
+
'metric': 'rmse'
|
15 |
+
```
|
16 |
+
|
17 |
+
以下参数我选择的初始值,你可以根据自己的情况来选择:
|
18 |
+
|
19 |
+
```
|
20 |
+
'max_depth': 6 ### 根据问题来定咯,由于我的数据集不是很大,所以选择了一个适中的值,其实4-10都无所谓。
|
21 |
+
'num_leaves': 50 ### 由于lightGBM是leaves_wise生长,官方说法是要小于2^max_depth
|
22 |
+
'subsample'/'bagging_fraction':0.8 ### 数据采样
|
23 |
+
'colsample_bytree'/'feature_fraction': 0.8 ### 特征采样
|
24 |
+
```
|
25 |
+
|
26 |
+
下面我是用LightGBM的cv函数进行演示:
|
27 |
+
|
28 |
+
```
|
29 |
+
params = {
|
30 |
+
'boosting_type': 'gbdt',
|
31 |
+
'objective': 'regression',
|
32 |
+
|
33 |
+
'learning_rate': 0.1,
|
34 |
+
'num_leaves': 50,
|
35 |
+
'max_depth': 6,
|
36 |
+
|
37 |
+
'subsample': 0.8,
|
38 |
+
'colsample_bytree': 0.8,
|
39 |
+
}
|
40 |
+
data_train = lgb.Dataset(df_train, y_train, silent=True)
|
41 |
+
cv_results = lgb.cv(
|
42 |
+
params, data_train, num_boost_round=1000, nfold=5, stratified=False, shuffle=True, metrics='rmse',
|
43 |
+
early_stopping_rounds=50, verbose_eval=50, show_stdv=True, seed=0)
|
44 |
+
|
45 |
+
print('best n_estimators:', len(cv_results['rmse-mean']))
|
46 |
+
print('best cv score:', cv_results['rmse-mean'][-1])
|
47 |
+
[50] cv_agg's rmse: 1.38497 + 0.0202823
|
48 |
+
best n_estimators: 43
|
49 |
+
best cv score: 1.3838664241
|
50 |
+
```
|
51 |
+
|
52 |
+
由于我的数据集不是很大,所以在学习率为0.1时,最优的迭代次数只有43。那么现在,我们就代入(0.1, 43)进入其他参数的tuning。但是还是建议,在硬件条件允许的条件下,学习率还是越小越好。
|
53 |
+
|
54 |
+
**Step2. max_depth 和 num_leaves**
|
55 |
+
|
56 |
+
这是提高精确度的最重要的参数。
|
57 |
+
|
58 |
+
`max_depth` :设置树深度,深度越大可能过拟合
|
59 |
+
|
60 |
+
`num_leaves`:因为 LightGBM 使用的是 leaf-wise 的算法,因此在调节树的复杂程度时,使用的是 num_leaves 而不是 max_depth。大致换算关系:num_leaves = 2^(max_depth),但是它的值的设置应该小于 2^(max_depth),否则可能会导致过拟合。
|
61 |
+
|
62 |
+
我们也可以同时调节这两个参数,对于这两个参数调优,我们先粗调,再细调:
|
63 |
+
|
64 |
+
这里我们引入`sklearn`里的`GridSearchCV()`函数进行搜索。不知道怎的,这个函数特别耗内存,特别耗时间,特别耗精力。
|
65 |
+
|
66 |
+
```
|
67 |
+
from sklearn.model_selection import GridSearchCV
|
68 |
+
### 我们可以创建lgb的sklearn模型,使用上面选择的(学习率,评估器数目)
|
69 |
+
model_lgb = lgb.LGBMRegressor(objective='regression',num_leaves=50,
|
70 |
+
learning_rate=0.1, n_estimators=43, max_depth=6,
|
71 |
+
metric='rmse', bagging_fraction = 0.8,feature_fraction = 0.8)
|
72 |
+
|
73 |
+
params_test1={
|
74 |
+
'max_depth': range(3,8,2),
|
75 |
+
'num_leaves':range(50, 170, 30)
|
76 |
+
}
|
77 |
+
gsearch1 = GridSearchCV(estimator=model_lgb, param_grid=params_test1, scoring='neg_mean_squared_error', cv=5, verbose=1, n_jobs=4)
|
78 |
+
gsearch1.fit(df_train, y_train)
|
79 |
+
gsearch1.grid_scores_, gsearch1.best_params_, gsearch1.best_score_
|
80 |
+
Fitting 5 folds for each of 12 candidates, totalling 60 fits
|
81 |
+
|
82 |
+
|
83 |
+
[Parallel(n_jobs=4)]: Done 42 tasks | elapsed: 2.0min
|
84 |
+
[Parallel(n_jobs=4)]: Done 60 out of 60 | elapsed: 3.1min finished
|
85 |
+
|
86 |
+
|
87 |
+
([mean: -1.88629, std: 0.13750, params: {'max_depth': 3, 'num_leaves': 50},
|
88 |
+
mean: -1.88629, std: 0.13750, params: {'max_depth': 3, 'num_leaves': 80},
|
89 |
+
mean: -1.88629, std: 0.13750, params: {'max_depth': 3, 'num_leaves': 110},
|
90 |
+
mean: -1.88629, std: 0.13750, params: {'max_depth': 3, 'num_leaves': 140},
|
91 |
+
mean: -1.86917, std: 0.12590, params: {'max_depth': 5, 'num_leaves': 50},
|
92 |
+
mean: -1.86917, std: 0.12590, params: {'max_depth': 5, 'num_leaves': 80},
|
93 |
+
mean: -1.86917, std: 0.12590, params: {'max_depth': 5, 'num_leaves': 110},
|
94 |
+
mean: -1.86917, std: 0.12590, params: {'max_depth': 5, 'num_leaves': 140},
|
95 |
+
mean: -1.89254, std: 0.10904, params: {'max_depth': 7, 'num_leaves': 50},
|
96 |
+
mean: -1.86024, std: 0.11364, params: {'max_depth': 7, 'num_leaves': 80},
|
97 |
+
mean: -1.86024, std: 0.11364, params: {'max_depth': 7, 'num_leaves': 110},
|
98 |
+
mean: -1.86024, std: 0.11364, params: {'max_depth': 7, 'num_leaves': 140}],
|
99 |
+
{'max_depth': 7, 'num_leaves': 80},
|
100 |
+
-1.8602436718814157)
|
101 |
+
```
|
102 |
+
|
103 |
+
这里,我们运行了12个参数组合,得到的最优解是在max_depth为7,num_leaves为80的情况下,分数为-1.860。
|
104 |
+
|
105 |
+
这里必须说一下,sklearn模型评估里的scoring参数都是采用的**higher return values are better than lower return values(较高的返回值优于较低的返回值)**。
|
106 |
+
|
107 |
+
但是,我采用的metric策略采用的是均方误差(rmse),越低越好,所以sklearn就提供了`neg_mean_squared_erro`参数,也就是返回metric的负数,所以就均方差来说,也就变成负数越大越好了。
|
108 |
+
|
109 |
+
所以,可以看到,最优解的分数为-1.860,转化为均方差为np.sqrt(-(-1.860)) = 1.3639,明显比step1的分数要好很多。
|
110 |
+
|
111 |
+
至此,我们将我们这步得到的最优解代入第三步。其实,我这里只进行了粗调,如果要得到更好的效果,可以将max_depth在7附近多取几个值,num_leaves在80附近多取几个值。千万不要怕麻烦,虽然这确实很麻烦。
|
112 |
+
|
113 |
+
```
|
114 |
+
params_test2={
|
115 |
+
'max_depth': [6,7,8],
|
116 |
+
'num_leaves':[68,74,80,86,92]
|
117 |
+
}
|
118 |
+
|
119 |
+
gsearch2 = GridSearchCV(estimator=model_lgb, param_grid=params_test2, scoring='neg_mean_squared_error', cv=5, verbose=1, n_jobs=4)
|
120 |
+
gsearch2.fit(df_train, y_train)
|
121 |
+
gsearch2.grid_scores_, gsearch2.best_params_, gsearch2.best_score_
|
122 |
+
Fitting 5 folds for each of 15 candidates, totalling 75 fits
|
123 |
+
|
124 |
+
|
125 |
+
[Parallel(n_jobs=4)]: Done 42 tasks | elapsed: 2.8min
|
126 |
+
[Parallel(n_jobs=4)]: Done 75 out of 75 | elapsed: 5.1min finished
|
127 |
+
|
128 |
+
|
129 |
+
([mean: -1.87506, std: 0.11369, params: {'max_depth': 6, 'num_leaves': 68},
|
130 |
+
mean: -1.87506, std: 0.11369, params: {'max_depth': 6, 'num_leaves': 74},
|
131 |
+
mean: -1.87506, std: 0.11369, params: {'max_depth': 6, 'num_leaves': 80},
|
132 |
+
mean: -1.87506, std: 0.11369, params: {'max_depth': 6, 'num_leaves': 86},
|
133 |
+
mean: -1.87506, std: 0.11369, params: {'max_depth': 6, 'num_leaves': 92},
|
134 |
+
mean: -1.86024, std: 0.11364, params: {'max_depth': 7, 'num_leaves': 68},
|
135 |
+
mean: -1.86024, std: 0.11364, params: {'max_depth': 7, 'num_leaves': 74},
|
136 |
+
mean: -1.86024, std: 0.11364, params: {'max_depth': 7, 'num_leaves': 80},
|
137 |
+
mean: -1.86024, std: 0.11364, params: {'max_depth': 7, 'num_leaves': 86},
|
138 |
+
mean: -1.86024, std: 0.11364, params: {'max_depth': 7, 'num_leaves': 92},
|
139 |
+
mean: -1.88197, std: 0.11295, params: {'max_depth': 8, 'num_leaves': 68},
|
140 |
+
mean: -1.89117, std: 0.12686, params: {'max_depth': 8, 'num_leaves': 74},
|
141 |
+
mean: -1.86390, std: 0.12259, params: {'max_depth': 8, 'num_leaves': 80},
|
142 |
+
mean: -1.86733, std: 0.12159, params: {'max_depth': 8, 'num_leaves': 86},
|
143 |
+
mean: -1.86665, std: 0.12174, params: {'max_depth': 8, 'num_leaves': 92}],
|
144 |
+
{'max_depth': 7, 'num_leaves': 68},
|
145 |
+
-1.8602436718814157)
|
146 |
+
```
|
147 |
+
|
148 |
+
可见最大深度7是没问题的,但是看细节的话,发现在最大深度为7的情况下,叶结点的数量对分数并没有影响。
|
149 |
+
|
150 |
+
**Step3: min_data_in_leaf 和 min_sum_hessian_in_leaf**
|
151 |
+
|
152 |
+
说到这里,就该降低过拟合了。
|
153 |
+
|
154 |
+
`min_data_in_leaf` 是一个很重要的参数, 也叫min_child_samples,它的值取决于训练数据的样本个树和num_leaves. 将其设置的较大可以避免生成一个过深的树, 但有可能导致欠拟合。
|
155 |
+
|
156 |
+
`min_sum_hessian_in_leaf`:也叫min_child_weight,使一个结点分裂的最小海森值之和,真拗口(Minimum sum of hessians in one leaf to allow a split. Higher values potentially decrease overfitting)
|
157 |
+
|
158 |
+
我们采用跟上面相同的方法进行:
|
159 |
+
|
160 |
+
```
|
161 |
+
params_test3={
|
162 |
+
'min_child_samples': [18, 19, 20, 21, 22],
|
163 |
+
'min_child_weight':[0.001, 0.002]
|
164 |
+
}
|
165 |
+
model_lgb = lgb.LGBMRegressor(objective='regression',num_leaves=80,
|
166 |
+
learning_rate=0.1, n_estimators=43, max_depth=7,
|
167 |
+
metric='rmse', bagging_fraction = 0.8, feature_fraction = 0.8)
|
168 |
+
gsearch3 = GridSearchCV(estimator=model_lgb, param_grid=params_test3, scoring='neg_mean_squared_error', cv=5, verbose=1, n_jobs=4)
|
169 |
+
gsearch3.fit(df_train, y_train)
|
170 |
+
gsearch3.grid_scores_, gsearch3.best_params_, gsearch3.best_score_
|
171 |
+
Fitting 5 folds for each of 10 candidates, totalling 50 fits
|
172 |
+
|
173 |
+
|
174 |
+
[Parallel(n_jobs=4)]: Done 42 tasks | elapsed: 2.9min
|
175 |
+
[Parallel(n_jobs=4)]: Done 50 out of 50 | elapsed: 3.3min finished
|
176 |
+
|
177 |
+
|
178 |
+
([mean: -1.88057, std: 0.13948, params: {'min_child_samples': 18, 'min_child_weight': 0.001},
|
179 |
+
mean: -1.88057, std: 0.13948, params: {'min_child_samples': 18, 'min_child_weight': 0.002},
|
180 |
+
mean: -1.88365, std: 0.13650, params: {'min_child_samples': 19, 'min_child_weight': 0.001},
|
181 |
+
mean: -1.88365, std: 0.13650, params: {'min_child_samples': 19, 'min_child_weight': 0.002},
|
182 |
+
mean: -1.86024, std: 0.11364, params: {'min_child_samples': 20, 'min_child_weight': 0.001},
|
183 |
+
mean: -1.86024, std: 0.11364, params: {'min_child_samples': 20, 'min_child_weight': 0.002},
|
184 |
+
mean: -1.86980, std: 0.14251, params: {'min_child_samples': 21, 'min_child_weight': 0.001},
|
185 |
+
mean: -1.86980, std: 0.14251, params: {'min_child_samples': 21, 'min_child_weight': 0.002},
|
186 |
+
mean: -1.86750, std: 0.13898, params: {'min_child_samples': 22, 'min_child_weight': 0.001},
|
187 |
+
mean: -1.86750, std: 0.13898, params: {'min_child_samples': 22, 'min_child_weight': 0.002}],
|
188 |
+
{'min_child_samples': 20, 'min_child_weight': 0.001},
|
189 |
+
-1.8602436718814157)
|
190 |
+
```
|
191 |
+
|
192 |
+
这是我经过粗调后细调的结果,可以看到,min_data_in_leaf的最优值为20,而min_sum_hessian_in_leaf对最后的值几乎没有影响。且这里调参之后,最后的值没有进行优化,说明之前的默认值即为20,0.001。
|
193 |
+
|
194 |
+
**Step4: feature_fraction 和 bagging_fraction**
|
195 |
+
|
196 |
+
这两个参数都是为了降低过拟合的。
|
197 |
+
|
198 |
+
feature_fraction参数来进行特征的子抽样。这个参数可以用来防止过拟合及提高训练速度。
|
199 |
+
|
200 |
+
bagging_fraction+bagging_freq参数必须同时设置,bagging_fraction相当于subsample样本采样,可以使bagging更快的运行,同时也可以降拟合。bagging_freq默认0,表示bagging的频率,0意味着没有使用bagging,k意味着每k轮迭代进行一次bagging。
|
201 |
+
|
202 |
+
不同的参数,同样的方法。
|
203 |
+
|
204 |
+
```
|
205 |
+
params_test4={
|
206 |
+
'feature_fraction': [0.5, 0.6, 0.7, 0.8, 0.9],
|
207 |
+
'bagging_fraction': [0.6, 0.7, 0.8, 0.9, 1.0]
|
208 |
+
}
|
209 |
+
model_lgb = lgb.LGBMRegressor(objective='regression',num_leaves=80,
|
210 |
+
learning_rate=0.1, n_estimators=43, max_depth=7,
|
211 |
+
metric='rmse', bagging_freq = 5, min_child_samples=20)
|
212 |
+
gsearch4 = GridSearchCV(estimator=model_lgb, param_grid=params_test4, scoring='neg_mean_squared_error', cv=5, verbose=1, n_jobs=4)
|
213 |
+
gsearch4.fit(df_train, y_train)
|
214 |
+
gsearch4.grid_scores_, gsearch4.best_params_, gsearch4.best_score_
|
215 |
+
Fitting 5 folds for each of 25 candidates, totalling 125 fits
|
216 |
+
|
217 |
+
|
218 |
+
[Parallel(n_jobs=4)]: Done 42 tasks | elapsed: 2.6min
|
219 |
+
[Parallel(n_jobs=4)]: Done 125 out of 125 | elapsed: 7.1min finished
|
220 |
+
|
221 |
+
|
222 |
+
([mean: -1.90447, std: 0.15841, params: {'bagging_fraction': 0.6, 'feature_fraction': 0.5},
|
223 |
+
mean: -1.90846, std: 0.13925, params: {'bagging_fraction': 0.6, 'feature_fraction': 0.6},
|
224 |
+
mean: -1.91695, std: 0.14121, params: {'bagging_fraction': 0.6, 'feature_fraction': 0.7},
|
225 |
+
mean: -1.90115, std: 0.12625, params: {'bagging_fraction': 0.6, 'feature_fraction': 0.8},
|
226 |
+
mean: -1.92586, std: 0.15220, params: {'bagging_fraction': 0.6, 'feature_fraction': 0.9},
|
227 |
+
mean: -1.88031, std: 0.17157, params: {'bagging_fraction': 0.7, 'feature_fraction': 0.5},
|
228 |
+
mean: -1.89513, std: 0.13718, params: {'bagging_fraction': 0.7, 'feature_fraction': 0.6},
|
229 |
+
mean: -1.88845, std: 0.13864, params: {'bagging_fraction': 0.7, 'feature_fraction': 0.7},
|
230 |
+
mean: -1.89297, std: 0.12374, params: {'bagging_fraction': 0.7, 'feature_fraction': 0.8},
|
231 |
+
mean: -1.89432, std: 0.14353, params: {'bagging_fraction': 0.7, 'feature_fraction': 0.9},
|
232 |
+
mean: -1.88088, std: 0.14247, params: {'bagging_fraction': 0.8, 'feature_fraction': 0.5},
|
233 |
+
mean: -1.90080, std: 0.13174, params: {'bagging_fraction': 0.8, 'feature_fraction': 0.6},
|
234 |
+
mean: -1.88364, std: 0.14732, params: {'bagging_fraction': 0.8, 'feature_fraction': 0.7},
|
235 |
+
mean: -1.88987, std: 0.13344, params: {'bagging_fraction': 0.8, 'feature_fraction': 0.8},
|
236 |
+
mean: -1.87752, std: 0.14802, params: {'bagging_fraction': 0.8, 'feature_fraction': 0.9},
|
237 |
+
mean: -1.88348, std: 0.13925, params: {'bagging_fraction': 0.9, 'feature_fraction': 0.5},
|
238 |
+
mean: -1.87472, std: 0.13301, params: {'bagging_fraction': 0.9, 'feature_fraction': 0.6},
|
239 |
+
mean: -1.88656, std: 0.12241, params: {'bagging_fraction': 0.9, 'feature_fraction': 0.7},
|
240 |
+
mean: -1.89029, std: 0.10776, params: {'bagging_fraction': 0.9, 'feature_fraction': 0.8},
|
241 |
+
mean: -1.88719, std: 0.11915, params: {'bagging_fraction': 0.9, 'feature_fraction': 0.9},
|
242 |
+
mean: -1.86170, std: 0.12544, params: {'bagging_fraction': 1.0, 'feature_fraction': 0.5},
|
243 |
+
mean: -1.87334, std: 0.13099, params: {'bagging_fraction': 1.0, 'feature_fraction': 0.6},
|
244 |
+
mean: -1.85412, std: 0.12698, params: {'bagging_fraction': 1.0, 'feature_fraction': 0.7},
|
245 |
+
mean: -1.86024, std: 0.11364, params: {'bagging_fraction': 1.0, 'feature_fraction': 0.8},
|
246 |
+
mean: -1.87266, std: 0.12271, params: {'bagging_fraction': 1.0, 'feature_fraction': 0.9}],
|
247 |
+
{'bagging_fraction': 1.0, 'feature_fraction': 0.7},
|
248 |
+
-1.8541224387666373)
|
249 |
+
```
|
250 |
+
|
251 |
+
从这里可以看出来,bagging_feaction和feature_fraction的理想值分别是1.0和0.7,一个很重要原因就是,我的样本数量比较小(4000+),但是特征数量很多(1000+)。所以,这里我们取更小的步长,对feature_fraction进行更细致的取值。
|
252 |
+
|
253 |
+
```
|
254 |
+
params_test5={
|
255 |
+
'feature_fraction': [0.62, 0.65, 0.68, 0.7, 0.72, 0.75, 0.78 ]
|
256 |
+
}
|
257 |
+
model_lgb = lgb.LGBMRegressor(objective='regression',num_leaves=80,
|
258 |
+
learning_rate=0.1, n_estimators=43, max_depth=7,
|
259 |
+
metric='rmse', min_child_samples=20)
|
260 |
+
gsearch5 = GridSearchCV(estimator=model_lgb, param_grid=params_test5, scoring='neg_mean_squared_error', cv=5, verbose=1, n_jobs=4)
|
261 |
+
gsearch5.fit(df_train, y_train)
|
262 |
+
gsearch5.grid_scores_, gsearch5.best_params_, gsearch5.best_score_
|
263 |
+
Fitting 5 folds for each of 7 candidates, totalling 35 fits
|
264 |
+
|
265 |
+
|
266 |
+
[Parallel(n_jobs=4)]: Done 35 out of 35 | elapsed: 2.3min finished
|
267 |
+
|
268 |
+
|
269 |
+
([mean: -1.86696, std: 0.12658, params: {'feature_fraction': 0.62},
|
270 |
+
mean: -1.88337, std: 0.13215, params: {'feature_fraction': 0.65},
|
271 |
+
mean: -1.87282, std: 0.13193, params: {'feature_fraction': 0.68},
|
272 |
+
mean: -1.85412, std: 0.12698, params: {'feature_fraction': 0.7},
|
273 |
+
mean: -1.88235, std: 0.12682, params: {'feature_fraction': 0.72},
|
274 |
+
mean: -1.86329, std: 0.12757, params: {'feature_fraction': 0.75},
|
275 |
+
mean: -1.87943, std: 0.12107, params: {'feature_fraction': 0.78}],
|
276 |
+
{'feature_fraction': 0.7},
|
277 |
+
-1.8541224387666373)
|
278 |
+
```
|
279 |
+
|
280 |
+
好吧,feature_fraction就是0.7了
|
281 |
+
|
282 |
+
**Step5: 正则化参数**
|
283 |
+
|
284 |
+
正则化参数lambda_l1(reg_alpha), lambda_l2(reg_lambda),毫无疑问,是降低过拟合的,两者分别对应l1正则化和l2正则化。我们也来尝试一下使用这两个参数。
|
285 |
+
|
286 |
+
```
|
287 |
+
params_test6={
|
288 |
+
'reg_alpha': [0, 0.001, 0.01, 0.03, 0.08, 0.3, 0.5],
|
289 |
+
'reg_lambda': [0, 0.001, 0.01, 0.03, 0.08, 0.3, 0.5]
|
290 |
+
}
|
291 |
+
model_lgb = lgb.LGBMRegressor(objective='regression',num_leaves=80,
|
292 |
+
learning_rate=0.b1, n_estimators=43, max_depth=7,
|
293 |
+
metric='rmse', min_child_samples=20, feature_fraction=0.7)
|
294 |
+
gsearch6 = GridSearchCV(estimator=model_lgb, param_grid=params_test6, scoring='neg_mean_squared_error', cv=5, verbose=1, n_jobs=4)
|
295 |
+
gsearch6.fit(df_train, y_train)
|
296 |
+
gsearch6.grid_scores_, gsearch6.best_params_, gsearch6.best_score_
|
297 |
+
Fitting 5 folds for each of 49 candidates, totalling 245 fits
|
298 |
+
|
299 |
+
|
300 |
+
[Parallel(n_jobs=4)]: Done 42 tasks | elapsed: 2.8min
|
301 |
+
[Parallel(n_jobs=4)]: Done 192 tasks | elapsed: 10.6min
|
302 |
+
[Parallel(n_jobs=4)]: Done 245 out of 245 | elapsed: 13.3min finished
|
303 |
+
|
304 |
+
|
305 |
+
([mean: -1.85412, std: 0.12698, params: {'reg_alpha': 0, 'reg_lambda': 0},
|
306 |
+
mean: -1.85990, std: 0.13296, params: {'reg_alpha': 0, 'reg_lambda': 0.001},
|
307 |
+
mean: -1.86367, std: 0.13634, params: {'reg_alpha': 0, 'reg_lambda': 0.01},
|
308 |
+
mean: -1.86787, std: 0.13881, params: {'reg_alpha': 0, 'reg_lambda': 0.03},
|
309 |
+
mean: -1.87099, std: 0.12476, params: {'reg_alpha': 0, 'reg_lambda': 0.08},
|
310 |
+
mean: -1.87670, std: 0.11849, params: {'reg_alpha': 0, 'reg_lambda': 0.3},
|
311 |
+
mean: -1.88278, std: 0.13064, params: {'reg_alpha': 0, 'reg_lambda': 0.5},
|
312 |
+
mean: -1.86190, std: 0.13613, params: {'reg_alpha': 0.001, 'reg_lambda': 0},
|
313 |
+
mean: -1.86190, std: 0.13613, params: {'reg_alpha': 0.001, 'reg_lambda': 0.001},
|
314 |
+
mean: -1.86515, std: 0.14116, params: {'reg_alpha': 0.001, 'reg_lambda': 0.01},
|
315 |
+
mean: -1.86908, std: 0.13668, params: {'reg_alpha': 0.001, 'reg_lambda': 0.03},
|
316 |
+
mean: -1.86852, std: 0.12289, params: {'reg_alpha': 0.001, 'reg_lambda': 0.08},
|
317 |
+
mean: -1.88076, std: 0.11710, params: {'reg_alpha': 0.001, 'reg_lambda': 0.3},
|
318 |
+
mean: -1.88278, std: 0.13064, params: {'reg_alpha': 0.001, 'reg_lambda': 0.5},
|
319 |
+
mean: -1.87480, std: 0.13889, params: {'reg_alpha': 0.01, 'reg_lambda': 0},
|
320 |
+
mean: -1.87284, std: 0.14138, params: {'reg_alpha': 0.01, 'reg_lambda': 0.001},
|
321 |
+
mean: -1.86030, std: 0.13332, params: {'reg_alpha': 0.01, 'reg_lambda': 0.01},
|
322 |
+
mean: -1.86695, std: 0.12587, params: {'reg_alpha': 0.01, 'reg_lambda': 0.03},
|
323 |
+
mean: -1.87415, std: 0.13100, params: {'reg_alpha': 0.01, 'reg_lambda': 0.08},
|
324 |
+
mean: -1.88543, std: 0.13195, params: {'reg_alpha': 0.01, 'reg_lambda': 0.3},
|
325 |
+
mean: -1.88076, std: 0.13502, params: {'reg_alpha': 0.01, 'reg_lambda': 0.5},
|
326 |
+
mean: -1.87729, std: 0.12533, params: {'reg_alpha': 0.03, 'reg_lambda': 0},
|
327 |
+
mean: -1.87435, std: 0.12034, params: {'reg_alpha': 0.03, 'reg_lambda': 0.001},
|
328 |
+
mean: -1.87513, std: 0.12579, params: {'reg_alpha': 0.03, 'reg_lambda': 0.01},
|
329 |
+
mean: -1.88116, std: 0.12218, params: {'reg_alpha': 0.03, 'reg_lambda': 0.03},
|
330 |
+
mean: -1.88052, std: 0.13585, params: {'reg_alpha': 0.03, 'reg_lambda': 0.08},
|
331 |
+
mean: -1.87565, std: 0.12200, params: {'reg_alpha': 0.03, 'reg_lambda': 0.3},
|
332 |
+
mean: -1.87935, std: 0.13817, params: {'reg_alpha': 0.03, 'reg_lambda': 0.5},
|
333 |
+
mean: -1.87774, std: 0.12477, params: {'reg_alpha': 0.08, 'reg_lambda': 0},
|
334 |
+
mean: -1.87774, std: 0.12477, params: {'reg_alpha': 0.08, 'reg_lambda': 0.001},
|
335 |
+
mean: -1.87911, std: 0.12027, params: {'reg_alpha': 0.08, 'reg_lambda': 0.01},
|
336 |
+
mean: -1.86978, std: 0.12478, params: {'reg_alpha': 0.08, 'reg_lambda': 0.03},
|
337 |
+
mean: -1.87217, std: 0.12159, params: {'reg_alpha': 0.08, 'reg_lambda': 0.08},
|
338 |
+
mean: -1.87573, std: 0.14137, params: {'reg_alpha': 0.08, 'reg_lambda': 0.3},
|
339 |
+
mean: -1.85969, std: 0.13109, params: {'reg_alpha': 0.08, 'reg_lambda': 0.5},
|
340 |
+
mean: -1.87632, std: 0.12398, params: {'reg_alpha': 0.3, 'reg_lambda': 0},
|
341 |
+
mean: -1.86995, std: 0.12651, params: {'reg_alpha': 0.3, 'reg_lambda': 0.001},
|
342 |
+
mean: -1.86380, std: 0.12793, params: {'reg_alpha': 0.3, 'reg_lambda': 0.01},
|
343 |
+
mean: -1.87577, std: 0.13002, params: {'reg_alpha': 0.3, 'reg_lambda': 0.03},
|
344 |
+
mean: -1.87402, std: 0.13496, params: {'reg_alpha': 0.3, 'reg_lambda': 0.08},
|
345 |
+
mean: -1.87032, std: 0.12504, params: {'reg_alpha': 0.3, 'reg_lambda': 0.3},
|
346 |
+
mean: -1.88329, std: 0.13237, params: {'reg_alpha': 0.3, 'reg_lambda': 0.5},
|
347 |
+
mean: -1.87196, std: 0.13099, params: {'reg_alpha': 0.5, 'reg_lambda': 0},
|
348 |
+
mean: -1.87196, std: 0.13099, params: {'reg_alpha': 0.5, 'reg_lambda': 0.001},
|
349 |
+
mean: -1.88222, std: 0.14735, params: {'reg_alpha': 0.5, 'reg_lambda': 0.01},
|
350 |
+
mean: -1.86618, std: 0.14006, params: {'reg_alpha': 0.5, 'reg_lambda': 0.03},
|
351 |
+
mean: -1.88579, std: 0.12398, params: {'reg_alpha': 0.5, 'reg_lambda': 0.08},
|
352 |
+
mean: -1.88297, std: 0.12307, params: {'reg_alpha': 0.5, 'reg_lambda': 0.3},
|
353 |
+
mean: -1.88148, std: 0.12622, params: {'reg_alpha': 0.5, 'reg_lambda': 0.5}],
|
354 |
+
{'reg_alpha': 0, 'reg_lambda': 0},
|
355 |
+
-1.8541224387666373)
|
356 |
+
```
|
357 |
+
|
358 |
+
哈哈,看来我多此一举了。
|
359 |
+
|
360 |
+
**step6: 降低learning_rate**
|
361 |
+
|
362 |
+
之前使用较高的学习速率是因为可以让收敛更快,但是准确度肯定没有细水长流来的好。最后,我们使用较低的学习速率,以及使用更多的决策树n_estimators来训练数据,看能不能可以进一步的优化分数。
|
363 |
+
|
364 |
+
我们可以用回lightGBM的cv函数了 ,我们代入之前优化好的参数。
|
365 |
+
|
366 |
+
```
|
367 |
+
params = {
|
368 |
+
'boosting_type': 'gbdt',
|
369 |
+
'objective': 'regression',
|
370 |
+
|
371 |
+
'learning_rate': 0.005,
|
372 |
+
'num_leaves': 80,
|
373 |
+
'max_depth': 7,
|
374 |
+
'min_data_in_leaf': 20,
|
375 |
+
|
376 |
+
'subsample': 1,
|
377 |
+
'colsample_bytree': 0.7,
|
378 |
+
}
|
379 |
+
|
380 |
+
data_train = lgb.Dataset(df_train, y_train, silent=True)
|
381 |
+
cv_results = lgb.cv(
|
382 |
+
params, data_train, num_boost_round=10000, nfold=5, stratified=False, shuffle=True, metrics='rmse',
|
383 |
+
early_stopping_rounds=50, verbose_eval=100, show_stdv=True)
|
384 |
+
|
385 |
+
print('best n_estimators:', len(cv_results['rmse-mean']))
|
386 |
+
print('best cv score:', cv_results['rmse-mean'][-1])
|
387 |
+
[100] cv_agg's rmse: 1.52939 + 0.0261756
|
388 |
+
[200] cv_agg's rmse: 1.43535 + 0.0187243
|
389 |
+
[300] cv_agg's rmse: 1.39584 + 0.0157521
|
390 |
+
[400] cv_agg's rmse: 1.37935 + 0.0157429
|
391 |
+
[500] cv_agg's rmse: 1.37313 + 0.0164503
|
392 |
+
[600] cv_agg's rmse: 1.37081 + 0.0172752
|
393 |
+
[700] cv_agg's rmse: 1.36942 + 0.0177888
|
394 |
+
[800] cv_agg's rmse: 1.36854 + 0.0180575
|
395 |
+
[900] cv_agg's rmse: 1.36817 + 0.0188776
|
396 |
+
[1000] cv_agg's rmse: 1.36796 + 0.0190279
|
397 |
+
[1100] cv_agg's rmse: 1.36783 + 0.0195969
|
398 |
+
best n_estimators: 1079
|
399 |
+
best cv score: 1.36772351783
|
400 |
+
```
|
401 |
+
|
402 |
+
这就是一个大概过程吧,其实也有更高级的方法,但是这种基本的对于GBM模型的调参方法也是需要了解的吧。如有问题,请多指教。
|
app.py
ADDED
@@ -0,0 +1,135 @@
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|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
1 |
+
from definitions import *
|
2 |
+
|
3 |
+
st.set_option('deprecation.showPyplotGlobalUse', False)
|
4 |
+
st.sidebar.subheader("请选择模型参数:sunglasses:")
|
5 |
+
|
6 |
+
num_leaves = st.sidebar.slider(label = 'num_leaves', min_value = 4.0,
|
7 |
+
max_value = 16.0 ,
|
8 |
+
value = 10.0,
|
9 |
+
step = 0.1)
|
10 |
+
|
11 |
+
max_depth = st.sidebar.slider(label = 'max_depth', min_value = 8,
|
12 |
+
max_value = 15,
|
13 |
+
value = 10,
|
14 |
+
step = 1)
|
15 |
+
|
16 |
+
min_data_in_leaf = st.sidebar.slider(label = 'min_data_in_leaf', min_value = 8,
|
17 |
+
max_value = 15,
|
18 |
+
value = 10,
|
19 |
+
step = 1)
|
20 |
+
|
21 |
+
feature_fraction = st.sidebar.slider(label = 'feature_fraction', min_value = 0.0,
|
22 |
+
max_value = 1.0 ,
|
23 |
+
value = 0.3,
|
24 |
+
step = 0.1)
|
25 |
+
|
26 |
+
lambda_l1 = st.sidebar.slider(label = 'lambda_l1', min_value = 0.000,
|
27 |
+
max_value = 1.000 ,
|
28 |
+
value = 0.500,
|
29 |
+
step = 0.001)
|
30 |
+
|
31 |
+
lambda_l2 = st.sidebar.slider(label = 'lambda_l2', min_value = 1,
|
32 |
+
max_value = 72,
|
33 |
+
value = 36,
|
34 |
+
step = 1)
|
35 |
+
|
36 |
+
min_split_gain = st.sidebar.slider(label = 'min_split_gain', min_value = 6,
|
37 |
+
max_value = 289 ,
|
38 |
+
value = 144,
|
39 |
+
step = 1)
|
40 |
+
|
41 |
+
top_rate = st.sidebar.slider(label = 'top_rate', min_value = 0.0,
|
42 |
+
max_value = 1.0 ,
|
43 |
+
value = 0.3,
|
44 |
+
step = 0.1)
|
45 |
+
|
46 |
+
other_rate = st.sidebar.slider(label = 'other_rate', min_value = 0.0,
|
47 |
+
max_value = 1.0 ,
|
48 |
+
value = 0.3,
|
49 |
+
step = 0.1)
|
50 |
+
|
51 |
+
min_data_per_group = st.sidebar.slider(label = 'min_data_per_group', min_value = 6,
|
52 |
+
max_value = 289 ,
|
53 |
+
value = 32,
|
54 |
+
step = 1)
|
55 |
+
|
56 |
+
max_cat_threshold = st.sidebar.slider(label = 'max_cat_threshold', min_value = 6,
|
57 |
+
max_value = 289 ,
|
58 |
+
value = 32,
|
59 |
+
step = 1)
|
60 |
+
|
61 |
+
learning_rate = st.sidebar.slider(label = 'learning_rate', min_value = 8.0,
|
62 |
+
max_value = 15.0,
|
63 |
+
value = 10.5,
|
64 |
+
step = 0.1)
|
65 |
+
|
66 |
+
num_leaves = st.sidebar.slider(label = 'num_leaves', min_value = 6,
|
67 |
+
max_value = 289 ,
|
68 |
+
value = 31,
|
69 |
+
step = 1)
|
70 |
+
|
71 |
+
min_gain_to_split = st.sidebar.slider(label = 'min_gain_to_split', min_value = 0.0,
|
72 |
+
max_value = 15.0,
|
73 |
+
value = 0.0,
|
74 |
+
step = 0.1)
|
75 |
+
|
76 |
+
|
77 |
+
max_bin = st.sidebar.slider(label = 'max_bin', min_value = 6,
|
78 |
+
max_value = 289 ,
|
79 |
+
value = 255,
|
80 |
+
step = 1)
|
81 |
+
|
82 |
+
num_iterations = st.sidebar.slider(label = 'num_iterations', min_value = 8,
|
83 |
+
max_value = 15,
|
84 |
+
value = 10,
|
85 |
+
step = 1)
|
86 |
+
|
87 |
+
st.title('LightGBM-parameter-tuning-with-streamlit')
|
88 |
+
|
89 |
+
|
90 |
+
# 加载数据
|
91 |
+
breast_cancer = load_breast_cancer()
|
92 |
+
data = breast_cancer.data
|
93 |
+
target = breast_cancer.target
|
94 |
+
|
95 |
+
# 划分训练数据和测试数据
|
96 |
+
X_train, X_test, y_train, y_test = train_test_split(data, target, test_size=0.2)
|
97 |
+
|
98 |
+
# 转换为Dataset数据格式
|
99 |
+
lgb_train = lgb.Dataset(X_train, y_train)
|
100 |
+
lgb_eval = lgb.Dataset(X_test, y_test, reference=lgb_train)
|
101 |
+
|
102 |
+
# 模型训练
|
103 |
+
params = {'num_leaves': num_leaves, 'max_depth': max_depth,
|
104 |
+
'min_data_in_leaf': min_data_in_leaf,
|
105 |
+
'feature_fraction': feature_fraction,
|
106 |
+
'lambda_l1': lambda_l1, 'lambda_l2': lambda_l2,
|
107 |
+
'min_split_gain': min_split_gain, 'top_rate': top_rate,
|
108 |
+
'other_rate': other_rate, 'min_data_per_group': min_data_per_group,
|
109 |
+
'max_cat_threshold': max_cat_threshold,
|
110 |
+
'learning_rate':learning_rate,'num_leaves':num_leaves,'min_gain_to_split':min_gain_to_split,
|
111 |
+
'max_bin':max_bin,'num_iterations':num_iterations
|
112 |
+
}
|
113 |
+
|
114 |
+
gbm = lgb.train(params, lgb_train, num_boost_round=2000, valid_sets=lgb_eval, early_stopping_rounds=500)
|
115 |
+
lgb_eval = lgb.Dataset(X_test, y_test, reference=lgb_train)
|
116 |
+
probs = gbm.predict(X_test, num_iteration=gbm.best_iteration) # 输出的是概率结果
|
117 |
+
|
118 |
+
fpr, tpr, thresholds = roc_curve(y_test, probs)
|
119 |
+
st.write('------------------------------------')
|
120 |
+
st.write('Confusion Matrix:')
|
121 |
+
|
122 |
+
st.write(confusion_matrix(y_test, np.where(probs > 0.5, 1, 0)))
|
123 |
+
|
124 |
+
|
125 |
+
|
126 |
+
st.write('------------------------------------')
|
127 |
+
st.write('Classification Report:')
|
128 |
+
report = classification_report(y_test, np.where(probs > 0.5, 1, 0), output_dict=True)
|
129 |
+
report_matrix = pd.DataFrame(report).transpose()
|
130 |
+
st.dataframe(report_matrix)
|
131 |
+
|
132 |
+
st.write('------------------------------------')
|
133 |
+
st.write('ROC:')
|
134 |
+
|
135 |
+
plot_roc(fpr, tpr)
|
definitions.py
ADDED
@@ -0,0 +1,24 @@
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
1 |
+
import pandas as pd
|
2 |
+
import streamlit as st
|
3 |
+
import numpy as np
|
4 |
+
from sklearn.model_selection import train_test_split
|
5 |
+
from sklearn.datasets import load_breast_cancer
|
6 |
+
from sklearn.metrics import roc_auc_score,roc_curve,auc,accuracy_score,classification_report,confusion_matrix,precision_recall_curve
|
7 |
+
import lightgbm as lgb
|
8 |
+
import matplotlib.pyplot as plt
|
9 |
+
import warnings
|
10 |
+
warnings.filterwarnings('ignore')
|
11 |
+
|
12 |
+
def plot_roc(fpr, tpr, label=None):
|
13 |
+
roc_auc = auc(fpr, tpr)
|
14 |
+
plt.title('Receiver Operating Characteristic')
|
15 |
+
plt.plot(fpr, tpr, 'b', label = 'AUC = %0.2f' % roc_auc)
|
16 |
+
plt.legend(loc = 'lower right')
|
17 |
+
plt.plot([0, 1], [0, 1],'r--')
|
18 |
+
plt.xlim([0, 1])
|
19 |
+
plt.ylim([0, 1])
|
20 |
+
plt.ylabel('True Positive Rate')
|
21 |
+
plt.xlabel('False Positive Rate')
|
22 |
+
plt.show()
|
23 |
+
st.pyplot()
|
24 |
+
|
git.sh
ADDED
@@ -0,0 +1,3 @@
|
|
|
|
|
|
|
|
|
1 |
+
git add .
|
2 |
+
git commit -m "1.0"
|
3 |
+
git push
|
requirements.txt
ADDED
@@ -0,0 +1,6 @@
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
1 |
+
pandas 1.3.1
|
2 |
+
streamlit 1.8.1
|
3 |
+
numpy 1.20.3
|
4 |
+
sklearn 0.0
|
5 |
+
lightgbm 3.3.2
|
6 |
+
matplotlib 3.4.2
|