Kopp Wiebke, Weinkauf Tino
IEEE Trans Vis Comput Graph. 2018 Aug 21. doi: 10.1109/TVCG.2018.2865265.
We consider temporally evolving trees with changing topology and data: tree nodes may persist for a time range, merge or split, and the associated data may change. Essentially, one can think of this as a time series of trees with a node correspondence per hierarchy level between consecutive time steps. Existing visualization approaches for such data include animated 2D treemaps, where the dynamically changing layout makes it difficult to observe the data in its entirety. We present a method to visualize this dynamic data in a static, nested, and space-filling visualization. This is based on two major contributions: First, the layout constitutes a graph drawing problem. We approach it for the entire time span at once using a combination of a heuristic and simulated annealing. Second, we propose a rendering that emphasizes the hierarchy through an adaption of the classic cushion treemaps. We showcase the wide range of applicability using data from feature tracking in time-dependent scalar fields, evolution of file system hierarchies, and world population.
树节点可能在一定时间范围内持续存在、合并或分裂，并且相关数据可能会发生变化。从本质上讲，可以将其视为一系列时间上的树，在连续的时间步之间，每个层次级别都存在节点对应关系。针对此类数据的现有可视化方法包括动画二维树状图，其中动态变化的布局使得难以全面观察数据。我们提出了一种在静态、嵌套且空间填充的可视化中呈现这种动态数据的方法。这基于两项主要贡献：第一，布局构成了一个图形绘制问题。我们通过结合启发式方法和模拟退火算法一次性处理整个时间跨度。第二，我们提出了一种渲染方法，通过改编经典的缓冲树状图来强调层次结构。我们使用来自时间相关标量场中的特征跟踪、文件系统层次结构的演变以及世界人口的数据展示了其广泛的适用性。
