给出一个二分kmeans的python代码
时间: 2023-11-12 19:51:05 浏览: 68
当然,我可以给您提供一个二分kmeans的Python代码。请参考以下代码示例:
```
import random
import numpy as np
from sklearn.cluster import KMeans
class BinaryKMeans:
def __init__(self, k, max_iters=100):
self.k = k
self.max_iters = max_iters
# 初始化质心为None
self.centroids = None
# 计算欧几里得距离
def euclidean_distance(self, a, b):
return np.linalg.norm(a - b)
def find_nearest_centroid(self, x, centroids):
nearest_centroid = None
min_distance = float('inf')
for centroid in centroids:
distance = self.euclidean_distance(x, centroid)
if distance < min_distance:
min_distance = distance
nearest_centroid = centroid
return nearest_centroid
def get_variance(self, cluster):
centroid = np.mean(cluster, axis=0)
var = np.sum((cluster - centroid) ** 2)
return var
def binary_kmeans(self, X):
n = X.shape[0]
# 初始化簇
clusters = []
clusters.append(X)
# 初始化簇的标识
cluster_labels = np.zeros(n)
for i in range(self.max_iters):
k = len(clusters)
if k >= self.k:
break
variances = []
new_clusters = []
# 对每个簇进行二分
for j in range(k):
cluster = clusters[j]
# 进行KMeans聚类
kmeans = KMeans(n_clusters=2, max_iter=50, random_state=0).fit(cluster)
# 获取KMeans聚类后的簇
cluster1 = cluster[kmeans.labels_ == 0]
cluster2 = cluster[kmeans.labels_ == 1]
# 计算两个簇的方差
var1 = self.get_variance(cluster1)
var2 = self.get_variance(cluster2)
variances.append(var1 + var2)
new_clusters.append(cluster1)
new_clusters.append(cluster2)
# 更新簇的标识
indices = np.where(cluster_labels == j)[0]
labels1 = kmeans.labels_[indices][kmeans.labels_[indices] == 0]
labels2 = kmeans.labels_[indices][kmeans.labels_[indices] == 1]
cluster_labels[indices[labels1]] = len(clusters)
cluster_labels[indices[labels2]] = len(clusters) + 1
# 更新质心
clusters = new_clusters
# 获取最终的质心
self.centroids = np.zeros((self.k, X.shape[1]))
for i in range(self.k):
cluster = X[cluster_labels == i]
centroid = np.mean(cluster, axis=0)
self.centroids[i] = centroid
return cluster_labels
if __name__ == '__main__':
# 随机生成100个二维数据点
X = np.random.rand(100, 2)
# 调用二分kmeans算法
binary_kmeans = BinaryKMeans(k=5)
labels = binary_kmeans.binary_kmeans(X)
print(labels)
```
希望能对您有所帮助,如有问题请随时提出。
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