DiffAni: Visualizing Dynamic Graphs with a Hybrid of Difference Maps and Animation

Abstract

Fig. 1. Given a dynamic graph defined over a series of time slices, our DiffAni hybrid visualization displays it as a sequence of consecutive tiles. Each tile may show one or more time slices, and there are three kinds of tiles: diff tiles (indicated with a solid border and two time slice numbers below them, e.g., the left-most tile), animation tiles (indicated with a dashed border and two time slice numbers below them, e.g., the tile covering time slices 2 to 3), and small multiple tiles (indicated with a solid border and a single time slice number below them, e.g., the right-most tile). Nodes and edges are colored in red if they are being removed, or green if they are being added, over time slices. The radial menu above is being used to convert a diff tile into two small multiple ("SM") tiles.Abstract-Visualization of dynamically changing networks (graphs) is a significant challenge for researchers. Previous work has experimentally compared animation, small multiples, and other techniques, and found trade-offs between these. One potential way to avoid such trade-offs is to combine previous techniques in a hybrid visualization. We present two taxonomies of visualizations of dynamic graphs: one of non-hybrid techniques, and one of hybrid techniques. We also describe a prototype, called DiffAni, that allows a graph to be visualized as a sequence of three kinds of tiles: diff tiles that show difference maps over some time interval, animation tiles that show the evolution of the graph over some time interval, and small multiple tiles that show the graph state at an individual time slice. This sequence of tiles is ordered by time and covers all time slices in the data. An experimental evaluation of DiffAni shows that our hybrid approach has advantages over non-hybrid techniques in certain cases.

Temporal Multivariate Networks

“…And even more recently, Rufiange et al have developed a hybrid approach that lets the user interactively combine or switch between animations, small multiples, and plots that explicitly indicate what has changed [90].…”

Can animation support the visualisation of dynamic graphs?

“…Situations where the structure of the graph changes substantially due to node insertions/deletions can be the cause of such movement. In many areas of the graph visualisation and information visualisation literature [10,46,8], animated transitions have been shown to be helpful when there are significant changes to the data and/or how it is arranged on the screen.…”

Node Overlap Removal for 1D Graph Layout

“…This aid in comparing elements of the network would be much more difficult to obtain with the other 4 visual representation strategies proposed by Rufiange and McGuffin [21], which are all based on a 2D graph layout. It is interesting to notice that none of them allows such an ease of analysis when the user needs to visually compare the count of publications over the years.…”

“…It corresponds to the total number of papers published by the author at PacificVis during this period. Rufiange and McGuffin [21] propose a taxonomy of 5 strategies for visualizing dynamic graphs (see Figure 2 of their article). It is important to notice that the concept of dynamic graph such as developed in the article covers both (i) topological changes and (ii) numerical attribute changes.…”