tomek links理论 Python代码
时间: 2024-01-13 15:04:22 浏览: 22
以下是使用Python实现Tomek links算法的示例代码:
```python
import numpy as np
from sklearn.neighbors import NearestNeighbors
def remove_tomek_links(X, y):
"""
Removes Tomek links from the dataset
"""
nn = NearestNeighbors(n_neighbors=2)
nn.fit(X)
# Find indices of all samples that are their own nearest neighbors
mask = np.squeeze(nn.kneighbors(X, return_distance=False)[:, 1] == np.arange(X.shape[0]))
# Find indices of all Tomek links
tl_mask = np.zeros_like(mask)
for i in range(X.shape[0]):
if mask[i] or y[i] == -1:
continue
nn_i = nn.kneighbors(X[i].reshape(1, -1), return_distance=False)[0][1]
if y[nn_i] != y[i]:
tl_mask[i] = True
# Remove Tomek links
X_clean = X[~tl_mask]
y_clean = y[~tl_mask]
return X_clean, y_clean
```
这段代码使用NearestNeighbors算法来寻找Tomek links,然后将它们从数据集中移除。注意,这个函数的输入参数y是类标签,其中-1表示未标记数据。这个函数将删除所有未标记数据的Tomek链接。