随机欠采样的代码都有哪几种
时间: 2023-10-11 07:11:35 浏览: 51
随机欠采样是一种简单有效的解决不平衡数据集问题的方法。以下是几种基于Python的随机欠采样方法的实现代码:
1. 随机欠采样(Random Under-Sampling)
```python
from imblearn.under_sampling import RandomUnderSampler
# ratio: 欠采样后正负样本的比例
rus = RandomUnderSampler(sampling_strategy=ratio)
X_resampled, y_resampled = rus.fit_resample(X, y)
```
2. Tomek Links
```python
from imblearn.under_sampling import TomekLinks
tl = TomekLinks(sampling_strategy='auto', n_jobs=-1)
X_resampled, y_resampled = tl.fit_resample(X, y)
```
3. One-Sided Selection
```python
from imblearn.under_sampling import OneSidedSelection
oss = OneSidedSelection(sampling_strategy='auto', n_jobs=-1)
X_resampled, y_resampled = oss.fit_resample(X, y)
```
4. Neighborhood Cleaning Rule
```python
from imblearn.under_sampling import NeighbourhoodCleaningRule
ncr = NeighbourhoodCleaningRule(sampling_strategy='auto', n_jobs=-1)
X_resampled, y_resampled = ncr.fit_resample(X, y)
```
这些方法都可以用于降低不平衡数据集中多数类样本的数量。需要注意的是,样本数量的过度下采样会导致信息丢失,因此应谨慎使用。