从整体到局部相互协调是示意性网络地图的关键所在,已有方法多是单纯地将线段作为示意基本单元,当空间要素分布不均衡时,容易产生示意结果全局表达不一致以及局部要素过于紧凑而变形的现象。考虑网络连通与网络闭合这两个性质,提出了一种化简分割生成方法,核心思想是根据连通化简网络,进而依据闭合构建网眼与线段两种基本示意单元。首先,对网络节点化简以及方向、长度调整,形成整体一致的化简网络;其次,将化简网络分割为网眼集合与线段集合;第三,建立从网眼至线段的示意化过程,通过网眼局部控制以避免要素过于紧凑。实验讨论了本文方法在不同示意约束规则之下的表现效果,与经典迭代寻优方法的对比分析表明,在网络整体形态保持与局部要素布置方面具有一定的优势。
The harmony of the whole and the local layout is the key to generating schematic network maps. The existing methods simply take line segments as the basic unit for schematization and easily cause global inconsistency or local deformation of schematic results when spatial distribution is not balanced. Considering the properties of connectivity and closure of network structures, this paper presents a new method to generate schematic maps by network simplification and partition. The core idea is simplifying network structures into meshes and lines. Firstly, the number of nodes are reduced and the direction and length of lines are adjusted to form a consistent simplification network. Secondly, the network structure is partitioned into a mesh set and line set. Thirdly, meshes and lines are schematized,avoiding local congestion by mesh schematization. An experiment shows the performance of our method under different constraints and makes comparisons with the classical iteration optimization method. Results indicate the advantages of our method in preserving the overall network shape and local element arrangements.