Python实现AGNES算法
时间: 2023-11-19 09:57:06 浏览: 75
AGNES算法是一种基于距离的聚类算法,其全称为自适应增量聚类算法(Agglomerative Nesting),它的主要思想是将每个样本看作一个初始的簇,然后将距离最近的两个簇合并成一个新的簇,直到满足某个终止条件为止。下面是Python实现AGNES算法的步骤:
1.导入必要的库和数据集
```python
import numpy as np
import pandas as pd
from scipy.spatial.distance import pdist,squareform
data = pd.read_csv('data.csv',header=None)
```
2.计算距离矩阵
```python
dist_matrix = pdist(data,metric='euclidean')
```
3.将每个样本看作一个初始的簇
```python
clusters = []
for i in range(data.shape[0]):
clusters.append([i])
```
4.合并距离最近的两个簇
```python
while len(clusters) > 2:
# 计算距离最近的两个簇的距离和索引
min_dist = np.inf
for i in range(len(clusters)):
for j in range(i+1,len(clusters)):
dist = np.mean(dist_matrix[clusters[i],clusters[j]])
if dist < min_dist:
min_dist = dist
merge_index = (i,j)
# 合并距离最近的两个簇
clusters[merge_index[0]] += clusters[merge_index[1]]
del clusters[merge_index[1]]
```
5.输出聚类后各个簇中数据点的编号
```python
print(clusters)
```