Graphics Reference
In-Depth Information
Summary
Tree drawing has been with us for a long time. Trees can clearly and
unambiguously show a hierarchy of relationships, such as organizational
charts, family trees, and decision trees. Or, a tree can be extracted from any
graph—family trees are actually graphs where the authors have chosen to
show only edges directly related to one immediate lineage.
Trees can be drawn with a minimum of overlap to create visually clear
diagrams. Furthermore, the many different ways to draw a tree can be used
to reveal different aspects of the hierarchy and the data.
You can use trees as an effective organizing device. A tree layout can be used
to organize a complex graph and then used as a template for drawing other
types of links on top of the tree.
However, for some types of analysis, such as understanding clusters that
exist in graphs, other approaches are needed. Chapter 11 discusses
techniques to identify and analyze clusters in graphs.
