为判断聚类结果质量的好坏，需要一个客观的评价指标来评价聚类结果的合理性。聚类性能评价方法通常分为三种：外部评价法，内部评价法，相对评价法。外部评价法将聚类结果得到类标签和已知类标签进行比较，此评价法的前提是数据集样本的类标签已知-In order to judge the quality of clustering results, good or bad, the need for an objective evaluation to assess the reasonableness of the clustering results. Clustering performance evaluation method is usually divided into three types: external evaluation method, internal evaluation method, relative evaluation method. External evaluation method of clustering results to obtain class labels and the known class labels are compared, the premise of this evaluation method is a class label known sample of the data set