python不用第三方库,使用皮尔逊系数计算多组多维数据的距离,最后进行dbscan聚类,给出聚类分组
时间: 2024-03-24 18:40:57 浏览: 127
python计算皮尔逊系数
好的,我可以帮你实现这个任务。以下是一个Python示例代码,用于实现你所需的功能:
```
import math
# 计算两个向量之间的皮尔逊系数
def pearson(x, y):
n = len(x)
sum_x = sum(x)
sum_y = sum(y)
sum_xy = sum([x[i] * y[i] for i in range(n)])
sum_x2 = sum([x[i] ** 2 for i in range(n)])
sum_y2 = sum([y[i] ** 2 for i in range(n)])
numerator = sum_xy - (sum_x * sum_y / n)
denominator = math.sqrt((sum_x2 - sum_x ** 2 / n) * (sum_y2 - sum_y ** 2 / n))
if denominator == 0:
return 0
else:
return numerator / denominator
# 计算距离矩阵
def distance_matrix(data):
n = len(data)
distances = [[0] * n for i in range(n)]
for i in range(n):
for j in range(i+1, n):
distances[i][j] = pearson(data[i], data[j])
distances[j][i] = distances[i][j]
return distances
# 使用DBSCAN算法进行聚类
def dbscan(data, eps, min_pts):
labels = [None] * len(data)
cluster = 0
for i in range(len(data)):
if labels[i] is not None:
continue
neighbors = get_neighbors(i, data, eps)
if len(neighbors) < min_pts:
labels[i] = -1
else:
cluster += 1
labels[i] = cluster
expand_cluster(i, neighbors, cluster, eps, min_pts, data, labels)
return labels
# 获取邻居点
def get_neighbors(point, data, eps):
neighbors = []
for i in range(len(data)):
if pearson(data[point], data[i]) >= eps:
neighbors.append(i)
return neighbors
# 扩展聚类
def expand_cluster(point, neighbors, cluster, eps, min_pts, data, labels):
for neighbor in neighbors:
if labels[neighbor] is None:
labels[neighbor] = cluster
new_neighbors = get_neighbors(neighbor, data, eps)
if len(new_neighbors) >= min_pts:
neighbors += new_neighbors
# 示例数据
data = [
[1, 2, 3, 4],
[2, 3, 4, 5],
[3, 4, 5, 6],
[4, 5, 6, 7],
[5, 6, 7, 8],
[6, 7, 8, 9],
[2, 4, 6, 8],
[1, 3, 5, 7],
[2, 4, 6, 8],
[1, 2, 3, 4],
[3, 5, 7, 9],
[4, 6, 8, 10]
]
# 计算距离矩阵
distances = distance_matrix(data)
# 聚类
labels = dbscan(distances, 0.5, 3)
# 输出聚类结果
for i in range(len(labels)):
print("第%d个样本的聚类标签为:%d" % (i+1, labels[i]))
```
在上面的示例代码中,我们使用了自定义的`pearson`函数计算两个向量之间的皮尔逊系数,然后使用`distance_matrix`函数计算距离矩阵。接着,我们使用DBSCAN算法进行聚类,并将聚类结果打印输出。
如果您需要使用自己的数据进行聚类,只需将示例数据替换为您自己的数据即可。此外,您还可以调整`dbscan`函数中的`eps`和`min_pts`参数以改变聚类效果。
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