unable to print the label and outline box of a cluster subgraph in graphviz

Question

I am a newbie to graphviz and the DOT language. I was trying out generating graphs with cluster subgprahs. However, when I have clusters, each with node positions exactly specified in the script, graphviz does not generate the outline boxes or the labels for the clusters! Specifically, if I have the following DOT script:

digraph G{
subgraph cluster0{
label="Cluster 0"
a->b
}
subgraph cluster1{
label="Cluster 1"
c->d
}
}

then the graph generated is:

However, with the following DOT script, in which I specify the node positions of the 4 nodes exactly:

digraph G{
subgraph cluster0{
label = "Cluster 0"
a[pos="10,200"]
b[pos="100,200"]
a->b
}
subgraph cluster1{
label = "Cluster 1"
c[pos="10,100"]
d[pos="100,100"]
c->d
}
}

The graph generated is:

Notice that in this case, neither the outline box for the clusters nor the labels for the clusters are printed!! In this case, there is a clear demarcation between the 2 clusters as you can see - the clusters don't overlap, so in principle graphviz should not have a problem showing them, am I right?

How can I tell graphviz to draw the cluster outline boxes and labels no matter what? Any help in this will be greatly appreciated!!

Thanks!

Answer 1

The dot layout engine doesn't support the pos attribute.

To render a graph with positions of all nodes predefined, you should use neato or fdp with the -n option.

neato doesn't support clusters (though it seems it should now). Fortunately, fdpdoes!

Therefore, you may use the following command:

dot -Tpdf -Kpdf -n -O filename.dot

or

fdp -Tpdf -n -O filename.dot

Unfortunately, the positions of the nodes relative to the cluster are ok, but clusters still seem to get moved by fdp (-n switch didn't make a difference).

I didn't try with the latest version (I used 2.29.20120504), but if the latest doesn't work neither, this may be a case for a bug report.

Btw, since positions are assumed to be in inches, this will create a very large graph.

---

Output I get with fdp (with or without -n switch) - I added size=20 to limit the image size:

---

Alternative solution without using pos:

digraph G{
subgraph cluster0{
label = "Cluster 0"
{rank=same; a->b;}
}
subgraph cluster1{
label = "Cluster 1"
{rank=same; c->d; }
}

a -> c [style=invis];
}

Answer 2

Your code is rendering fine in svg on viz.js. I am able to see borders around clusters.

Perhaps the graphviz version you use is old, an upgrade should fix the issue.