Chapter 6. Hierarchical visualization
This chapter covers
- Understanding hierarchical data principles
- Using dendrograms
- Learning about circle packs
- Working with treemaps
- Employing partitions
Complex data visualization is defined by its encoding of data types other than numerical data. We’ll start with dealing with hierarchical data, which encodes how things are related to other things, whether through dependency, lineage, or categorization. There are four different layouts we’ll look at in this chapter, each of which uses different methods to show a node and indicate the parent-child relationships between those nodes. For two of those charting methods—circle packing and treemaps—the way we signal parent-child relationship is via enclosure, which is to say that the parent graphical mark is drawn around the child graphical mark. In the other two charts, parent-child relationship is signaled by adjacency (in the case of the partition layout) or via connection (using lines in the dendrogram). See figure 6.1.
