Kyrix-S: Authoring Scalable Scatterplot Visualizations of Big Data
Kyrix-S: Authoring Scalable Scatterplot Visualizations of Big Data
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DOI：
10.1109/tvcg.2020.3030372
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发表时间：
2020-07
影响因子：
5.2
通讯作者：
Wenbo Tao;Xinli Hou;Adam Sah;L. Battle;Remco Chang;M. Stonebraker
中科院分区：
文献类型：
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作者：
Wenbo Tao;Xinli Hou;Adam Sah;L. Battle;Remco Chang;M. Stonebraker
静态散点图通常会遇到大数据集上的过度绘制问题，其中对象重叠会导致不希望的视觉混乱。在散点图中使用放大可以帮助缓解这个问题。通过多个缩放级别，可以使用更多的屏幕真实的空间，从而可以以不太拥挤的方式放置对象。我们称这种类型的可视化为可扩展散点图可视化，简称为SSV。尽管SSV具有潜力，但由于三个限制，现有的系统和工具包在支持SSV的创作方面存在不足。首先，许多系统具有有限的可扩展性，假设数据适合一台计算机的内存。第二，开发人员的工作太多，例如，使用自定义代码来生成标记布局或呈现对象是必需的。第三，许多系统只关注SSV设计空间的一个小子集（例如，支持特定类型的视觉标记）。为了解决这些局限性，我们开发了Kyrix-S，这是一个易于大规模创作SSV的系统。Kyrix-S基于散点图任务和设计的现有调查，导出了一种声明性语法，可以在几十行代码中指定各种SSV。分布式布局算法支持声明式语法，该算法自动将视觉标记放置到缩放级别上。我们将数据存储在多节点数据库中，并使用多节点空间索引来实现大型SSV的交互式浏览。大量的实验表明：1）Kyrix-S能够交互式浏览数十亿对象的SSV，响应时间低于500 ms; 2）与最先进的创作系统相比，Kyrix-S在规格上减少了4 - 9倍。
Static scatterplots often suffer from the overdraw problem on big datasets where object overlap causes undesirable visual clutter. The use of zooming in scatterplots can help alleviate this problem. With multiple zoom levels, more screen real estate is available, allowing objects to be placed in a less crowded way. We call this type of visualization scalable scatterplot visualizations, or SSV for short. Despite the potential of SSVs, existing systems and toolkits fall short in supporting the authoring of SSVs due to three limitations. First, many systems have limited scalability, assuming that data fits in the memory of one computer. Second, too much developer work, e.g., using custom code to generate mark layouts or render objects, is required. Third, many systems focus on only a small subset of the SSV design space (e.g. supporting a specific type of visual marks). To address these limitations, we have developed Kyrix-S, a system for easy authoring of SSVs at scale. Kyrix-S derives a declarative grammar that enables specification of a variety of SSVs in a few tens of lines of code, based on an existing survey of scatterplot tasks and designs. The declarative grammar is supported by a distributed layout algorithm which automatically places visual marks onto zoom levels. We store data in a multi-node database and use multi-node spatial indexes to achieve interactive browsing of large SSVs. Extensive experiments show that 1) Kyrix-S enables interactive browsing of SSVs of billions of objects, with response times under 500ms and 2) Kyrix-S achieves 4X-9X reduction in specification compared to a state-of-the-art authoring system.