While many graph drawing algorithms consider nodes as points, graph visualization tools often represent them as shapes. These shapes support the display of information such as labels or encode various data with size or color. However, they can create overlaps between nodes which hinder the exploration process by hiding parts of the information. It is therefore of utmost importance to remove these overlaps to improve graph visualization readability. If not handled by the layout process, Overlap Removal (OR) algorithms have been proposed as layout post-processing. As graph layouts usually convey information about their topology, it is important that OR algorithms preserve them as much as possible. We propose a novel algorithm that models OR as a joint stress and scaling optimization problem, and leverages efficient stochastic gradient descent. This approach is compared with state-of-the-art algorithms, and several quality metrics demonstrate its efficiency to quickly remove overlaps while retaining the initial layout structures.
翻译:虽然许多图形绘图算法将节点视为点, 图形可视化工具通常以形状表示它们。 这些形状支持显示标签或以大小或颜色编码各种数据等信息。 但是, 它们可以在节点之间产生重叠, 从而隐藏部分信息, 从而妨碍勘探进程。 因此, 最重要的是要消除这些重叠, 以提高图形可视化的可读性。 如果不由布局进程处理, 则将重叠删除( OR) 算法提议为布局后处理。 由于图形布局通常传递有关其地形的信息, OR 算法必须尽可能保存这些信息。 我们提议一种新型算法, 将OR 模型作为联合压力和缩放优化问题, 并使用高效的随机梯度梯度梯度梯位。 这种方法与最先进的算法比较, 一些质量计量法显示其效率可以快速消除重叠, 同时保留初始布局结构 。