更新 k-means2

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yky 2025-06-10 23:04:46 +08:00
parent 1eaa6c38b0
commit 886ac03f75

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@ -1,13 +1,34 @@
from copy import deepcopy
import numpy as np
import pandas as pd
from matplotlib import pyplot as plt
plt.rcParams['figure.figsize'] = (16,9)
from copy import deepcopy
# 设置图形样式
plt.rcParams['figure.figsize'] = (16, 9)
plt.style.use('ggplot')
# 创建示例数据并保存为CSV文件
def create_sample_data():
# 生成三个簇的示例数据
np.random.seed(42)
cluster1 = np.random.normal(loc=[0, 0], scale=1, size=(100, 2))
cluster2 = np.random.normal(loc=[10, 5], scale=1.5, size=(100, 2))
cluster3 = np.random.normal(loc=[5, 10], scale=1.2, size=(100, 2))
data = np.vstack([cluster1, cluster2, cluster3])
# 创建DataFrame并保存为CSV
df = pd.DataFrame(data, columns=['V1', 'V2'])
df.to_csv('xclara.csv', index=False)
# 创建示例CSV文件
create_sample_data()
# 从CSV读取数据
data = pd.read_csv('xclara.csv')
f1 = data['V1'].values
f2 = data['V2'].values
X = np.array(list(zip(f1, f2)))
# 距离计算函数
def dist(a, b, ax=1):
return np.linalg.norm(a - b, axis=ax)
@ -16,33 +37,49 @@ def dist(a, b, ax=1):
k = 3
# 随机初始化质心(修正:使用数据范围)
C_x = np.random.randint(0,np.max(X)-20, size=k)
C_y = np.random.randint(0,np.max(X)-20, size=k)
C_x = np.random.uniform(np.min(f1), np.max(f1), size=k)
C_y = np.random.uniform(np.min(f2), np.max(f2), size=k)
C = np.array(list(zip(C_x, C_y)), dtype=np.float32)
C_old = np.zeros(C.shape)
print(C)
clusters = np.zeros(len(X))
iteration_flag = dist(C,C_old,1)
tmp = 1
while iteration_flag.any() != 0 and tmp<20:
for i in range(len(X)):
distances = dist(X[i],C,1)
clusters[i] = clusters
C_old = deepcopy(C)
for i in range(C):
points = [X[j] for j in range(len(X)) if clusters[j] == i]
C[i] = np.mean(points,axis=0)
print('%d'%tmp)
tmp = tmp + 1
iteraction_flag = dist(C,C_old,1)
print('distance:',iteraction_flag)
colors = ['r','g','b','y','c','m']
fig,ax = plt.subplots()
for i in range(k):
points = np.array([X[j] for j in range(len(X) if clusters[j] == i)])
ax.scatter(points[:,0],points[:,1],s=7,c=colors[i])
ax.scatter(C[:,0],C[:,1],marker="*",s=200,c='black')
# 绘制初始数据点和质心(修正颜色拼写错误)
plt.scatter(f1, f2, c='black', s=7) # 修正:'balck' -> 'black'
plt.scatter(C_x, C_y, marker='*', s=200, c='red')
plt.title("Initial Data Points and Centroids")
plt.show()
# ---- 可选添加完整的K-Means算法实现 ----
# 复制原始质心用于后续更新
C_old = np.zeros(C.shape)
clusters = np.zeros(len(X))
error = dist(C, C_old, None)
# K-Means迭代
while error != 0:
# 分配点到最近质心
for i in range(len(X)):
distances = dist(X[i], C)
cluster = np.argmin(distances)
clusters[i] = cluster
# 保存旧质心
C_old = deepcopy(C)
# 计算新质心
for i in range(k):
points = [X[j] for j in range(len(X)) if clusters[j] == i]
if points:
C[i] = np.mean(points, axis=0)
# 计算质心移动距离
error = dist(C, C_old, None)
# 绘制最终聚类结果
colors = ['r', 'g', 'b', 'c', 'm', 'y']
fig, ax = plt.subplots()
for i in range(k):
points = np.array([X[j] for j in range(len(X)) if clusters[j] == i])
ax.scatter(points[:, 0], points[:, 1], s=7, c=colors[i])
ax.scatter(C[:, 0], C[:, 1], marker='*', s=200, c='black')
plt.title("Final Clustering Result")
plt.show()