GraphViz Node Placement and Rankdir

Question

I'm having very good luck with graphviz and have been able to make nearly every graph that I need. I'm trying to duplicate this:

http://en.wikipedia.org/wiki/File:ICS_Structure.PNG

as faithfully as I can. The bottom part of that graph all flows top to bottom and I've got that working fine. What I have not been able to do is place the first 3 children right below "Incident Commander". They branch left and right. Plus note how the edges are shared in the top 8 nodes. Is that possible with dot? I can deal with everything else but not those top nodes. Can someone give me a clue to solve this?

Answer 1

Two useful techniques for reproducing graph layouts are:

• Invisible nodes
• Rank constraints

Here's a quick try for the top nodes:

digraph g{
ranksep=0.2;

node[shape=box3d, width=2.3, height=0.6, fontname="Arial"];
n1[label="Incident Commander"];
n2[label="Public Information\nOfficer"];
n3[label="Liaison Officer"];
n4[label="Safety Officer"];
n5[label="Operations Section"];
n6[label="Planning Section"];
n7[label="Logistics Section"];
n8[label="Finance/Admin. Section"];

node[shape=none, width=0, height=0, label=""];
edge[dir=none];
n1 -> p1 -> p2 -> p3;
{rank=same; n2 -> p1 -> n3;}
{rank=same; n4 -> p2;}
{rank=same; p4 -> p5 -> p3 -> p6 -> p7;}
p4 -> n5;
p5 -> n6;
p6 -> n7;
p7 -> n8;
}

And here's the result: