python实现最短距离single linkage算法
时间: 2023-07-26 18:12:17 浏览: 86
好的,下面是Python实现最短距离single linkage算法的示例代码:
```python
import numpy as np
def single_linkage(X):
"""
:param X: numpy array of shape (n_samples, n_features)
:return: numpy array of shape (n_samples-1, 2)
"""
n = X.shape[0]
clusters = [[i] for i in range(n)]
distances = np.zeros((n, n))
# 计算初始距离矩阵
for i in range(n):
for j in range(i+1, n):
distances[i][j] = distances[j][i] = np.linalg.norm(X[i] - X[j])
# 合并最近的两个簇,直到所有点都在同一个簇中
while len(clusters) > 1:
min_dist = np.inf
for i in range(len(clusters)):
for j in range(i+1, len(clusters)):
for k in clusters[i]:
for l in clusters[j]:
if distances[k][l] < min_dist:
min_dist = distances[k][l]
merge_pair = (i, j)
i, j = merge_pair
new_cluster = clusters[i] + clusters[j]
clusters.pop(j)
clusters[i] = new_cluster
# 更新距离矩阵
for k in range(n):
if k != i and k != j:
distances[i][k] = distances[k][i] = min(distances[k][clusters[i][0]], distances[k][clusters[i][-1]])
return np.array([[clusters[i][0], clusters[i][1]] for i in range(len(clusters)-1)])
```
这里使用了numpy库进行数组操作和计算欧几里得距离。函数接受一个形状为(n_samples, n_features)的numpy数组X, 返回一个形状为(n_samples-1, 2)的numpy数组,其中每行是合并两个簇的点的下标。
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