顾及密度对比的多层次聚类点群选取方法

A Point Group Selecting Method Using Multi-level Clustering Considering Density Comparison

  • 摘要: 在语义信息缺乏的情况下进行点群选取是制图综合的难点之一。提出了一种新的通过多层次聚类进行点群选取的方法。首先,针对k-means聚类算法的不足,利用改进的密度峰值聚类算法实现点群自动聚类,主要表现为用基尼系数确定最优截断距离及用局部密度和相对距离的关系自动确定聚类中心。其次,提出一种顾及密度对比的选取策略,通过点群多层次聚类,将点群划分成不同等级的簇,确定不同等级的聚类中心,建立点群的层次树结构;依据方根定律计算的选取数量,按照各级别簇的点数比例,自上而下逐层分配待选取点数,确定选取对象,实现点群的自动选取和多尺度表达。对不同分布模式的点群进行实验,验证了该方法的普适性和有效性。

     

    Abstract: In the absence of semantic information, the selection of point group is one of the difficulties in cartographic generalization. This paper proposes a new multi-level clustering point group generalization method which takes into account density contrast. Firstly, in view of the shortcoming of k-means clustering algorithm, this paper uses an improved density peak clustering method to realize automatic clustering of point group, mainly reflects on determining the optimal cut-off distance by the Gini coefficient and uses the relation of local density and relative distance to detect the clustering centers. Secondly, we propose a point group selection strategy which takes into account density contrast, the point group is divided into clusters of different grade by multi-level clustering. The clustering centers of different grades are determined, and the hierarchical tree structure of point group data is established. The number of points to be selected is calculated according to the square root law, then allocated from top to bottom according to the number of clusters at each level, and the selected objects are determined, and automatic selection of points and multi-scale expression of point group are realized. Point groups experimental results with different distribution patterns show that the method described in this paper can get reasonable selection results, which verifies the universality and effectiveness of the method.

     

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