利用AP算法进行聚类:
首先导入需要的包:
from sklearn.cluster import AffinityPropagationfrom sklearn import metricsfrom sklearn.datasets.samples_generator import make_blobs
生成一组数据:
centers = [[1, 1], [-1, -1], [1, -1]]X, labels_true = make_blobs(n_samples=300, centers=centers, cluster_std=0.5, random_state=0)
以上代码包括3个类簇的中心点以及300个以这3个点为中心的样本点。
接下来要利用AP算法对这300个点进行聚类。
af = AffinityPropagation(preference=-50).fit(X) # preference采用负的欧氏距离cluster_centers_indices = af.cluster_centers_indices_labels = af.labels_ # 样本标签n_clusters_ = len(cluster_centers_indices) # 类簇数
打印各种评价指标分数:
print('估计的类簇数: %d' % n_clusters_)print('Homogeneity: %0.3f' % metrics.homogeneity_score(labels_true, labels))print('Completeness: %0.3f' %metrics.completeness_score(labels_true, labels))print('V-measure: %0.3f' %metrics.v_measure_score(labels_true, labels))print('Adjusted Rand Index:%0.3f' %metrics.adjusted_rand_score(labels_true, labels))print('Adjusted Mutual Information:%0.3f'%metrics.adjusted_mutual_info_score(labels_true, labels))print('Silhouette Coefficient:%0.3f' %metrics.silhouette_score(X, labels, metric='sqeuclidean')) # sqeuclidean欧式距离平方
可视化聚类结果:
导入画图需要的包:
import matplotlib.pyplot as pltfrom itertools import cycleplt.close('all') plt.figure(1)plt.clf() # 清除当前图的所有信息colors = cycle('bgrcmykbgrcmykbgrcmykbgrcmyk')
close()方法介绍【可忽略】
close方法简介:matplotlib.pyplot.close(*args) --- Close a figure window.close() by itself closes the current figureclose(fig) closes the Figure instance figclose(num) closes the figure number numclose(name) where name is a string, closes figure with that labelclose('all') closes all the figure windows
for k, col in zip(range(n_clusters_),colors): class_members = labels == k; print('k:',k) print('labels:',labels) print('cls_member--------',class_members) cluster_center = X[cluster_centers_indices[k]] print('cluster_center:', cluster_center) # 画样本点 plt.plot(X[class_members, 0], X[class_members, 1], col + '.') # 画中心点 plt.plot(cluster_center[0], cluster_center[1], 'o', markeredgecolor='k', markersize=28) # 划线 for x in X[class_members]: plt.plot([cluster_center[0], x[0]], [cluster_center[1], x[1]], col) plt.title('Estimated number of clusters:%d' %n_clusters_)plt.show()# 显示图
运行结果:
完整代码:
print(__doc__)from sklearn.cluster import AffinityPropagationfrom sklearn import metricsfrom sklearn.datasets.samples_generator import make_blobs# ################################################## generate sample datacenters = [[1, 1], [-1, -1], [1, -1]]X, labels_true = make_blobs(n_samples=300, centers=centers, cluster_std=0.5, random_state=0)# ######################################################## Compute Affinity Propagationaf = AffinityPropagation(preference=-50).fit(X) # preference采用负的欧氏距离cluster_centers_indices = af.cluster_centers_indices_labels = af.labels_ # 样本标签n_clusters_ = len(cluster_centers_indices) # 类簇数print('估计的类簇数: %d' % n_clusters_)print('Homogeneity: %0.3f' % metrics.homogeneity_score(labels_true, labels))print('Completeness: %0.3f' %metrics.completeness_score(labels_true, labels))print('V-measure: %0.3f' %metrics.v_measure_score(labels_true, labels))print('Adjusted Rand Index:%0.3f' %metrics.adjusted_rand_score(labels_true, labels))print('Adjusted Mutual Information:%0.3f'%metrics.adjusted_mutual_info_score(labels_true, labels))print('Silhouette Coefficient:%0.3f' %metrics.silhouette_score(X, labels, metric='sqeuclidean')) # sqeuclidean欧式距离平方# ########################################################### Plot resultimport matplotlib.pyplot as pltfrom itertools import cycleplt.close('all')plt.figure(1)plt.clf()colors = cycle('bgrcmykbgrcmykbgrcmykbgrcmyk')for k, col in zip(range(n_clusters_),colors): class_members = labels == k; print('k:',k) print('labels:',labels) print('cls_member--------',class_members) cluster_center = X[cluster_centers_indices[k]] print('cluster_center:', cluster_center) plt.plot(X[class_members, 0], X[class_members, 1], col + '.') plt.plot(cluster_center[0], cluster_center[1], 'o', markeredgecolor='k', markersize=28) # 划线 for x in X[class_members]: plt.plot([cluster_center[0], x[0]], [cluster_center[1], x[1]], col)plt.title('Estimated number of clusters:%d' %n_clusters_)plt.show()