Density map is an effective visualization technique for depicting the scalar field distribution in 2D space. Conventional methods for constructing density maps are mainly based on Euclidean distance, limiting their applicability in urban analysis that shall consider road network and urban traffic. In this work, we propose a new method named Topology Density Map, targeting for accurate and intuitive density maps in the context of urban environment. Based on the various constraints of road connections and traffic conditions, the method first constructs a directed acyclic graph (DAG) that propagates nonlinear scalar fields along 1D road networks. Next, the method extends the scalar fields to a 2D space by identifying key intersecting points in the DAG, dividing the underlying territory into planar regions using a weighted Voronoi diagram, and calculating the scalar fields for every point. Two case studies demonstrate that the Topology Density Map supplies accurate information to users and provides an intuitive visualization for decision making. An interview with domain experts demonstrates the feasibility, usability, and effectiveness of our method.
翻译:密度图是描述2D空间天平分布面积的有效直观化技术。建造密度图的常规方法主要以欧几里德距离为基础,限制了其在城市分析中考虑到公路网和城市交通的可应用性。在这项工作中,我们提出了名为地形密度图的新方法,目标是在城市环境中绘制准确和直观的密度图。基于道路连接和交通条件的各种限制,该方法首先构建了一条直接的单流图(DAG),该图在1D公路网络上传播非线性天平地。接下来,该方法通过确定DAG的关键交叉点、使用加权的Voronoiois图将地下区域划分为平面区域并计算每个点的斜度区域,将斜度图扩大到2D空间。两项案例研究表明,“地形密度图”为用户提供了准确的信息,并为决策提供了直观的直观直观直观可见性。与域专家的访谈显示了我们的方法的可行性、可用性和有效性。