5 Graph Description Language (GDL) - Absint

4.1.3 Example
Figure 7 shows a nested graph in different grouping and folding stages. This graph consists of
five subgraphs: Graph A to Graph E. Graph B and C are subgraphs of Graph A. Graph E is a
subgraph of Graph D.
1. All graphs are clustered. In this case it is not possible to choose a different layout for subgraphs.
2. All graphs are boxed. Boxed graphs are drawn in independent frames. Edges between nodes
in different frames are substituted by edges between frames. For example, edge I–>M is
represented by the substitute edge Graph C–>M and edge L–>Graph E is represented by
substitute edge Graph A–>Graph D.
Note: Different layout algorithms or layout parameters can be chosen within boxes. For
example, graph B is drawn in a force-directed layout, graph C in a tree layout with a top
down orientation and graph E right-left-oriented.
3. The frames of graphs B, C, and E are now folded. Nodes inside these frames, i. e. the nodes
of the corresponding subgraphs, disappear.
4. The frames of graphs A and D are unfolded and the formerly substituted edges are shown.
Edge Graph C–>N is represented by the substitute edge Graph C–>Graph E, since N is
a node of the folded graph E.
5. The summary nodes of graphs B, C, and E are unfolded. No frames and summary nodes any
longer exist in this rendering. Therefore edges like Graph E–>N are substituted. Substituted
edges are introduced that start/end at the root node of a frame/subgraph. For example, edge
Graph E–>N is now represented by the substitute edge F–>N since F is the root node of
graph C.
6. Graphs A and D are boxed again, but graphs B, C, and E remain unfolded.
7. Graphs B, C, and E are wrapped. This operation doesn’t change the layout.
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