Drawing trees
Trees are a specific kind of graph where any two vertices are connected by exactly one path, which consists of edges. We may encounter them in mathematics, such as in graph theory, in computer science, or in any drawing that illustrates parent-children relationships in a hierarchical way.
We already know the node
and edge
operations, and the child
operation combines both of them. Specifically, it connects a parent node and one or more child nodes by edges, each from the parent to a child. Moreover, TikZ counts the children and determines an appropriate positioning for each of them.
A very simple example is this:
\node {A} child { node {1} edge from parent };
The output is this very simple tree:
Figure 6.1 – A simple tree
edge from parent
is a special path operation that adds an edge from the parent to the child. We can add options and nodes to this edge, as we know from Chapter 4, Drawing Edges and Arrows. For example,...