制图综合中等高线相交的判断和消除

An Algorithm for Detecting and Eliminating Intersection of Polylines in Cartographic Generalization

在线性综合中 ,人们总是先假设结果不产生自相交 ,但在实际应用中 ,由于算法或限差的选择不当都可能会引起曲线的相交或自相交 ,如等高线的综合。文章针对此问题介绍了一种基于单调链的划分来判断曲线自相交的算法 ,进而推广到判断曲线的相交 ;同时文章结合等高线的具体情况 ,提出了等高线综合中相交消除的解决方法。

Sometimes polylines intersect or self-intersect because of incorrect selection of algorithm or tolerance when they are simplified in cartographic generalization. Many algorithms avoid this problem, but it actually exists. In this paper,we develop an algorithm to detect it based on the partition of monotone chains, and analysis the situations in contour lines generalization, then present an efficient solution.