顾及地图要素级别的几何信息量量测方法

A measurement method of geometrical information considering multi-level map feature

类型和级别是作为地图要素表达的重要方式,但将其引入地图信息量量算是很困难的。本文在总结了传统量测方法不足的基础上,利用加权Voronoi图的空间划分特性,用各生成元面积比重新定义了熵的计算公式,基于经典信息量量算方法提出一种多级要素地图几何信息量量测方法;同时指出对多类地物应独立计算信息量。实验表明,该方法符合熵的相关结论,同时符合人的空间认知特性。

As an important approaches to express cartographic elements, multi-type and multilevel make it difficult to calculate the quantity of information in the map. In this paper, based on the drawback analysis of existing method, the authors use the spatial division property of weighted Voronoi diagrams, and a new formula of entropy by using the ratio between the Voronoi regions over the whole area. On the basis of classical measurement of information, this paper gives a new way to measure the information quantity in multilevel elements maps. At the same time, it indicates that people should calculate each object separately. The test result proves that the methods meet the correlative conclusion of entropy greatly, and it also corresponds with map reader's spatial perceptual property.