dbscan算法c++代码
时间: 2024-01-20 15:00:33 浏览: 82
dbscan.rar_DBSCAN_DBSCAN sql_dbsan_dbscan c++_聚类算法
dbscan算法是一种基于密度的聚类算法,可以通过代码实现。以下是一个简单的dbscan算法的Python代码示例:
```python
import numpy as np
from sklearn.neighbors import NearestNeighbors
def dbscan(X, eps, min_pts):
labels = [0]*len(X) # 初始化所有数据点的类别为0
cluster_num = 0 # 初始化聚类编号为0
for i in range(len(X)):
if labels[i] != 0:
continue # 如果数据点已经被标记过,则跳过
neighbors = NearestNeighbors(radius=eps).fit(X)
idxs = neighbors.radius_neighbors([X[i]], eps, return_distance=False)[0]
if len(idxs) < min_pts:
labels[i] = -1 # 标记为噪声点
else:
cluster_num += 1
expand_cluster(X, labels, i, idxs, cluster_num, eps, min_pts)
return labels
def expand_cluster(X, labels, i, idxs, cluster_num, eps, min_pts):
labels[i] = cluster_num # 将数据点i标记为当前的聚类编号
k = 0
while k < len(idxs):
idx = idxs[k]
if labels[idx] == -1: # 如果邻近点是噪声点,则将其标记为当前聚类的边界点
labels[idx] = cluster_num
elif labels[idx] == 0: # 如果邻近点没有被分类过
labels[idx] = cluster_num
neighbors = NearestNeighbors(radius=eps).fit(X)
idxs_ = neighbors.radius_neighbors([X[idx]], eps, return_distance=False)[0]
if len(idxs_) >= min_pts:
idxs = np.concatenate((idxs, idxs_)) # 将新发现的核心点的邻近点加入到idxs中
k += 1
# 使用示例
X = np.array([[1, 2], [2, 2], [2, 3], [8, 7], [8, 8], [25, 80]])
eps = 3
min_pts = 2
labels = dbscan(X, eps, min_pts)
print(labels) # 打印出每个数据点的聚类编号
```
以上的代码实现了dbscan算法的基本逻辑,通过对给定的数据集X、邻域半径eps和最小邻近点数min_pts进行处理,最终得到每个数据点的聚类编号。这个示例可以帮助理解dbscan算法的工作原理,并可以根据实际需求进行进一步的优化和调整。
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