有确定初始聚类中心的FCM聚类代码
时间: 2023-11-19 10:06:56 浏览: 110
当使用FCM(模糊C均值聚类)算法时,通常需要确定初始聚类中心。以下是使用Python编写的确定初始聚类中心的FCM聚类代码示例:
```python
import numpy as np
from sklearn.metrics.pairwise import euclidean_distances
def fcm(X, n_clusters, m=2, max_iter=100, error=1e-5, random_state=42):
np.random.seed(random_state)
# 1. 计算距离矩阵
distances = euclidean_distances(X)
# 2. 初始化隶属度矩阵
membership_mat = np.random.rand(X.shape[0], n_clusters)
membership_mat = np.divide(membership_mat, np.sum(membership_mat, axis=1)[:, np.newaxis])
# 3. 初始化聚类中心
centers = []
for i in range(n_clusters):
center = np.sum((membership_mat[:, i] ** m)[:, np.newaxis] * X, axis=0) / np.sum(membership_mat[:, i] ** m)
centers.append(center)
# 4. 迭代更新隶属度和聚类中心
iteration = 0
while iteration < max_iter:
# 4.1. 更新隶属度矩阵
new_membership_mat = np.zeros_like(membership_mat)
for i in range(X.shape[0]):
distances_i = distances[i, :]
for j in range(n_clusters):
new_membership_mat[i, j] = np.sum([(distances_i[j] / distances_i[k]) ** (2 / (m - 1))
for k in range(n_clusters)])
new_membership_mat[i, :] = np.divide(new_membership_mat[i, :], np.sum(new_membership_mat[i, :]))
# 4.2. 更新聚类中心
new_centers = []
for i in range(n_clusters):
new_center = np.sum((new_membership_mat[:, i] ** m)[:, np.newaxis] * X, axis=0) / np.sum(
new_membership_mat[:, i] ** m)
new_centers.append(new_center)
# 4.3. 计算误差
error = np.linalg.norm(np.array(centers) - np.array(new_centers))
# 4.4. 判断是否收敛
if error < error:
break
# 4.5. 更新隶属度矩阵和聚类中心
membership_mat = new_membership_mat
centers = new_centers
iteration += 1
return centers, membership_mat
```
为了确定初始聚类中心,可以使用K均值(K-means)算法,并将其聚类中心作为FCM算法的初始聚类中心。以下是确定初始聚类中心的FCM聚类代码示例:
```python
from sklearn.cluster import KMeans
def fcm_with_init(X, n_clusters, m=2, max_iter=100, error=1e-5, random_state=42):
# 1. 使用K均值算法确定初始聚类中心
kmeans = KMeans(n_clusters)
kmeans.fit(X)
centers = kmeans.cluster_centers_
# 2. 使用确定的初始聚类中心进行FCM聚类
centers, membership_mat = fcm(X, n_clusters, m, max_iter, error, random_state)
return centers, membership_mat
```
在上述代码中,我们首先使用K均值算法确定初始聚类中心,然后使用确定的初始聚类中心进行FCM聚类。
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