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cs.CG计算几何2
2606.12008 2026-06-11 cs.CG cs.GR 新提交

Automated Responsive Thematic Mapping with Layout Guides

基于布局引导的自动化响应式专题制图

Arjen Simons, Sarah Schöttler, Wouter Meulemans, Kevin Verbeek, Bettina Speckmann

AI总结 提出首个算法框架,通过布局引导结构高效计算响应式专题地图,实现地图元素在不同显示尺寸下的平滑自适应,兼顾统计信息可读性与制图上下文。

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AI中文摘要

专题地图以视觉方式传达关于空间单元(如国家或州)的统计信息。它们必须平衡承载统计信息的地图元素的个体可读性与整体制图上下文。如今,大多数地图不再是静态图像,而必须灵活响应各种设备类型和显示尺寸。当前的响应式专题制图方法存在局限性:对从业者而言劳动密集,且通常依赖组合不连贯的视觉编码以覆盖不同设备类型。在本文中,我们首次提出一种算法框架,用于高效计算能平滑适应不同显示尺寸的响应式专题地图。我们框架的关键组件是布局引导:一种组合结构,编码了专题地图的两个基本方面。第一个方面是每个统计地图元素的视觉需求(至少其期望的宽度和高度),第二个方面是以地图元素相对位置形式呈现的制图上下文。我们的主要算法贡献是地图排列器,它接收视觉容器作为输入,并返回合适的布局引导。地图排列器以稳定且一致的方式实现:如果容器变化很小,布局引导也变化很小,且相同的输入容器总是产生相同的布局引导。要使用我们的框架,需要三个要素:$(1)$ 参考布局,对应于“理想”的专题地图,$(2)$ 所有地图元素的总体垂直和水平顺序(针对具有极端宽高比的容器的期望布局),以及$(3)$ 能够从布局引导构建专题地图的专题制图算法。我们在两种类型的专题地图上演示了我们的框架,即矩形和Demers面积图。

英文摘要

Thematic maps visually communicate statistical information about spatial units such as countries or states. They must balance the individual readability of those map elements that carry the statistical information and the overall cartographic context. Nowadays, most maps are not static images, but must flexibly respond to a range of device types and display sizes. Current approaches to responsive thematic mapping are limited: they are labor-intensive for practitioners and often rely on combining disjointed visual encodings to cover different device types. In this paper we introduce the first algorithmic framework to efficiently compute responsive thematic maps that smoothly adapt to different display sizes. A key component of our framework is the layout guide: a combinatorial structure which encodes the two essential aspects of a thematic map. The first aspect are the visual requirements of each statistical map element (at least their desired width and height), the second aspect is the cartographic context in the form of relative positions of map elements. Our main algorithmic contribution is the map arranger which takes a visual container as input and returns a suitable layout guide. The map arranger does so in a stable and consistent manner: if the container changes only a little, then so does the layout guide, and the same input container always results in the same layout guide. To use our framework, one needs three ingredients: $(1)$ a reference layout, which corresponds to the ``ideal'' thematic map, $(2)$ a total vertical and horizontal order for all map elements (the desired layouts for containers with extreme aspect ratios), and $(3)$ a thematic mapping algorithm that can construct a thematic map from a layout guide. We demonstrate our framework on two types of thematic maps, namely rectangular and Demers cartograms.

2504.13819 2026-06-11 math.CO cs.CG 版本更新

Ordered Yao graphs: maximum degree, edge density, and clique numbers

有序Yao图:最大度、边密度和团数

Péter Ágoston, Adrian Dumitrescu, Arsenii Sagdeev, Karamjeet Singh, Ji Zeng

AI总结 研究有序Yao图的最大度、边数和团数的极值,给出不同扇区数下的精确或渐近界,并证明所有构造可有效实现。

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Comments
18 pages, 12 figures
AI中文摘要

对于正整数$k$和平面上一组有序的$n$个点,定义其\textit{$k$-扇区有序Yao图}如下:将每个点周围的平面分成$k$个相等的扇区,并从每个点向每个扇区中其最近的前驱点连一条边。我们分析了这些图的几个自然参数。主要结果如下:I 设$d_k(n)$为最大整数,使得对于平面上任意$n$个点的集合,存在一个顺序,使得对应的$k$-扇区有序Yao图的最大度至少为$d_k(n)$。我们证明,若$k=4$或$k\ge 6$,则$d_k(n)=n-1$,并对剩余的$k$值给出一些估计。具体地,我们证明$d_1(n)=\Theta(\log n)$;$\frac{1}{2}(n-1)\le d_3(n)\le 5\left\lceil\frac{n}{6}\right\rceil-1$;$\frac{2}{3}(n-1)\le d_5(n)\le n-1$;II 设$e_k(n)$为最小整数,使得对于平面上任意$n$个点的集合,存在一个顺序,使得对应的$k$-扇区有序Yao图至多有$e_k(n)$条边。则$e_k(n)=\left\lceil\frac{k}{2}\right\rceil\cdot n-o(n)$。III 设$w_k$为最小整数,使得对于平面上任意点集,存在一个顺序,使得对应的$k$-扇区有序Yao图的团数至多为$w_k$。则$\left\lceil\frac{k}{2}\right\rceil\le w_k\le\left\lceil\frac{k}{2}\right\rceil+1$。上述所有顺序均可有效构造。

英文摘要

For a positive integer $k$ and an ordered set of $n$ points in the plane, define its \textit{k-sector ordered Yao graphs} as follows. Divide the plane around each point into $k$ equal sectors and draw an edge from each point to its closest predecessor in each of the $k$ sectors. We analyze several natural parameters of these graphs. Our main results are as follows: I Let $d_k(n)$ be the maximum integer so that for every $n$-element point set in the plane, there exists an order such that the corresponding $k$-sector ordered Yao graph has maximum degree at least $d_k(n)$. We show that $d_k(n)=n-1$ if $k=4$ or $k \ge 6$, and provide some estimates for the remaining values of $k$. Namely, we show that $d_1(n) = \Theta( \log {n} )$; $\frac{1}{2}(n-1) \le d_3(n) \le 5\left\lceil\frac{n}{6}\right\rceil-1$; $\frac{2}{3}(n-1) \le d_5(n) \le n-1$; II Let $e_k(n)$ be the minimum integer so that for every $n$-element point set in the plane, there exists an order such that the corresponding $k$-sector ordered Yao graph has at most $e_k(n)$ edges. Then $e_k(n)=\left\lceil\frac{k}{2}\right\rceil\cdot n-o(n)$. III Let $w_k$ be the minimum integer so that for every point set in the plane, there exists an order such that the corresponding $k$-sector ordered Yao graph has clique number at most $w_k$. Then $\lceil\frac{k}{2}\rceil \le w_k\le \lceil\frac{k}{2}\rceil+1$. All the orders mentioned above can be constructed effectively.